Sleep Disorders
Sleep-related bruxism
Apr. 14, 2024
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Sleep and parkinsonism …
- Updated 12.21.2023
- Released 10.11.1993
- Expires For CME 12.21.2026
Sleep and parkinsonism
Introduction
Overview
The significant impact of Parkinson disease on sleep was clearly noted in James Parkinson’s remarkable description of the illness in his 1817 monograph, “An Essay on the Shaking Palsy.” He correctly noted that the motoric symptoms of Parkinson disease, such as severe nocturnal emergent tremor or nocturnal immobility, have great potential to interrupt sleep. Today, we are aware that the sleep-Parkinson disease interaction takes many other forms, including the effect of Parkinson drugs or Parkinson-associated behavioral symptoms (depression and psychosis) on sleep, and the (mostly beneficial) effect of sleep on the symptoms of the disease. The author highlights the common sleep disorders found in Parkinson disease, looking at both the potential etiologies and treatment options. One of the most striking sleep problems in Parkinson disease is excessive daytime sleepiness, which is in part due to medication side effects, but also highly correlated with age and duration of disease. We have also learned that many sleep disorders that are moderately common in the general population, such as restless legs syndrome and REM sleep behavior disorder, could be more prevalent among Parkinson patients, the latter condition sometimes antedating clinical Parkinson disease by years. Finally, this update discusses the role of circadian disruption in the development of Parkinson disease, an exciting new area of research and potential intervention.
Key points
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• REM sleep behavior disorder is one of the most common sleep disorders associated with Parkinson disease and sometimes antedates the motoric features of Parkinson disease by years. | |
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• Daytime sleepiness and fatigue are common complaints in Parkinson disease patients, especially in the elderly and in men. | |
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• Circadian dysfunction is an important emerging component of sleep dysfunction in Parkinson disease, with recent demonstration of changes in melatonin release patterns and potential benefits seen from timed bright light exposure. | |
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• The common notion that parkinsonian tremor disappears entirely during sleep is not completely true as tremor can re-emerge, sometimes significantly, during sleep arousals. | |
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• Bedtime dosages of dopaminergic medications, especially long-acting preparations, are very useful to combat nocturnal re-emergent parkinsonian symptoms, such as high-amplitude tremor or severe akinesia, while in bed, which can significantly disrupt sleep. |
Historical note and terminology
In 1817 James Parkinson, a medical practitioner from the township of Shoreditch, published his remarkable monograph entitled “An Essay on the Shaking Palsy.” In this monograph he described six patients he had observed with a unique neurologic disorder that would later come to bear his name. In the first six lines of this monograph, he confirmed the prominent clinical features of this condition much as we know them today:
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. . . involuntary tremulous motion, with lessened muscular power, in parts not in action and even when supported. . . with a propensity to bend the trunk forwards, and to pass from a walking to a running pace. . . the senses and intellects being uninjured. |
In addition to its classical features, Parkinson was also well aware of the syndrome’s interaction with sleep. On page 7 of his 63-page monograph he noted, “The tremulous motion of the limbs occurs during sleep, and augment until they awaken the patient and frequently with much agitation and alarm.” Commenting on the potential severity of tremor in advanced Parkinson patients, Parkinson goes on to state, “but even when exhausted nature seizes a small portion of sleep, the motion becomes so violent as not only to shake the bed-hangings, but even the floor and sashes of the room” (75). Parkinson’s vivid and concise descriptions of this syndrome and its accompaniments remain among the most remarkable and venerated accomplishments in clinical neurology. Although he coined the Latinized term “paralysis agitans” in place of shaking palsy, both terms have gradually disappeared in favor of Parkinson disease, the title that honors the master clinician. Today, even those conditions that clinically resemble Parkinson disease, although they are histologically different, are referred to collectively as the Parkinson syndromes.
Clinical manifestations
Presentation and course
Deterioration of sleep quality and duration are considered as markers of the prodromal phase of parkinsonism (57). Sleep abnormalities are common nonmotor symptoms of Parkinson disease, interesting as many as 93% of Parkinson disease patients. In a cross-sectional study on 157 Parkinson disease patients using an actigraph for six consecutive nights, a significant difference in objective sleep quality and quantity between Parkinson disease patients and controls has been found (48).
Altered NREM sleep microstructure is present even at an early stage of Parkinson disease, suggesting an early alteration of the central pathways involved in NREM sleep building-up and stability (81).
More importantly, it was demonstrated that poor sleep quality in patients with Parkinson disease correlates with impaired cognition (82; 59), pain scores (70), and the presence of comorbid sleep disorders is predictive of increased nonmotor symptoms. In contrast, a good sleep quality characterized by deeper slow wave sleep might relate to a more benign course of Parkinson disease (97). However, it is often difficult to ascertain whether the reported sleep disturbances are related to Parkinson disease itself or to the antiparkinsonian drugs. For example, it may be difficult to determine whether sleep disruption unrelated to Parkinson medications is caused by nocturnal reemergence of akinesia, rigidity or tremor, associated parasomnias, disruption of the circadian rhythm, or a primary alteration of sleep architecture. A polysomnographic study on 23 drug-naïve Parkinson disease patients showed a reduced sleep efficiency, longer sleep latency, and reduced duration of stage 3 NREM and rapid eye movement sleep compared to controls (37). Twelve patients were subsequently evaluated after two months of levodopa therapy with a significant improvement of sleep efficiency and reduction of sleep latency and wake-after-sleep-onset (37).
Most of the mechanisms by which Parkinson disease can affect sleep become more prominent as the illness progresses, explaining why studies of mild Parkinson disease patients may not uncover the full spectrum of sleep disturbances (122). In an Italian cohort study looking at 1072 patients with Parkinson disease, fatigue was the most common symptom (58%), followed by insomnia (37%), REM sleep behavior disorder (30%), excessive daytime sleepiness (21%), and restless legs syndrome (15%) (09).
Insomnia and Parkinson disease. Insomnia in Parkinson disease is multifactorial, with multiple components of the underlying disease process and treatment modalities contributing to difficulty falling asleep and maintaining sleep. Early-onset parkinsonism had a higher risk for developing post-motor insomnia compared with typical-onset parkinsonism (61). Nonmotor symptoms (fatigue, depressed mood, anxiety and autonomic problems) are closely associated with reported insomnia (93).
Parkinson disease patients suffer from increased sleep latency and an increased frequency of nocturnal arousals.
These frequent arousals may stem in part from abnormalities in sleep architecture that are present in Parkinson disease, including a reduction in total slow-wave and REM sleep and a decrease in sleep spindle density. The reduction in slow-wave sleep in Parkinson patients correlates with age and duration of disease, but not with the administration of daytime dopaminergic medications.
Each of the fundamental motor signs of Parkinson disease: tremor, rigidity, and bradykinesia, can also contribute to sleep fragmentation and result in complaints such as immobility in bed and pain related to nocturnal rigidity. The exact sequence of events that leads to awakening in patients with these nocturnal motoric symptoms is less clear. Tremor, once thought to disappear entirely in sleep, is now known to be one of the causes of arousals in Parkinson disease patients. Polysomnographic studies have shown that tremor usually appears in stage 1 or 2 of NREM sleep, after arousals, and during sleep stage transitions, in an attenuated form. This attenuated tremor may not result in awakening, but after a true awakening, no matter the cause, more severe tremor can appear and can be associated with sleep disturbance. Severe tremor may also prevent patients from initiating sleep at bedtime, as noted in James Parkinson’s original monograph.
Bradykinesia can also contribute to sleep disturbance (11). In some patients with advanced disease, the effect of dopaminergic medication can wear off as the night progresses. The severe immobility that results from this will cause sleep disturbances in those patients.
Nocturnal immobility is a significant complaint in Parkinson disease patients. Parkinson disease patients sleep more frequently in a supine position than controls and the supine position is associated with a higher apnea-hypopnea index end excessive daytime sleepiness. Moreover, it was demonstrated that patients with nocturnal immobility reported significantly worse subjective sleep quality and objectively had significantly lower sleep efficiency. Seventy-nine percent of Parkinson disease patients indicated the need to void at night, yet 35% were unable to get out of bed unaided (114). The third fundamental symptom of Parkinson disease, rigidity, may appear during an awakening, resulting in pain that prevents the resumption of sleep.
The potential for re-emergent parkinsonian symptoms to disrupt sleep suggests that nighttime dosages of antiparkinsonian medications might improve sleep (37). There is some controversy, however, about whether a bedtime dose of levodopa or a dopamine agonist improves sleep in Parkinson disease. Clinical experience suggests that in many moderately severe to advanced Parkinson disease patients, nocturnal amelioration of significant motor signs is often an important step in attempting to normalize sleep. This can be accomplished by around-the-clock dosing with antiparkinsonian medications, or more simply, with administration of a bedtime dose of sustained release carbidopa-levodopa, a sustained-release dopamine agonist, or the transdermal dopamine agonist, rotigotine. Rotigotine reduces nocturnal motor activity, duration of wake episodes after sleep onset (WASO), nocturia, pain, and coexisting sleep disorders such as restless legs syndrome; it may also reduce the number and duration of daytime sleep episodes in Parkinson disease patients (16; 78). There is also the possibility that antiparkinsonian drugs can alter sleep. Because of its potentially alerting amphetamine metabolites, the MAO-B inhibiting agent selegiline can result in insomnia. However, rasagiline does not have amphetamine metabolites and may have a lower potential to cause or exacerbate insomnia. Rasagiline administration significantly reduces the mean sleep latency and increases the mean total sleep time (96). Levodopa has the potential to alter sleep architecture, especially in the months immediately after the initiation of therapy. In some patients, dopaminergic drugs administered at high dosages late in the evening can increase sleep latency and result in sleep fragmentation (103). Accordingly, unless a late evening dosage of levodopa or dopamine agonist is required to control nocturnal motor symptoms, it should be eliminated or distanced from bedtime.
A variety of behavioral side effects that might adversely affect sleep can result from antiparkinsonian therapy, including memory loss, confusion, paranoia, psychosis, hallucinations, and vivid dreaming. Among these adverse effects, nocturnal hallucinations and vivid dreaming have the greatest potential to interrupt sleep. With chronic dopaminergic therapy, some patients report that dreams become increasingly vivid even though dream content remains relatively unchanged. Medication-induced vivid dreams not only have the potential to interrupt sleep, but they have been thought to be a premonitory sign of hallucinations and advanced psychosis, suggesting the need for treatment. The initial event in this behavioral cascade leading from vivid dreaming to overt hallucinations may be a reduction in REM sleep related to levodopa therapy. This progression is most likely to occur in Parkinson disease patients who are aged, cognitively impaired, and already have disturbed nocturnal sleep of any cause. Prospective studies of this sequence of events have questioned the predictive significance of vivid dreams, but, despite this controversy, it still seems advisable to reduce the bedtime dosage of antiparkinsonian drugs and distance it from bedtime, if possible, when vivid dreams appear. Although levodopa and the dopamine agonists are the most common triggers, anticholinergic drugs, selegiline, and amantadine can also produce this syndrome. Their intake should be reduced first before attempting to taper more clinically effective primary dopaminergic agents.
Dyskinesias are abnormal involuntary movements resulting from dopaminergic therapy that are usually choreiform or dystonic in nature. Typically, choreiform dyskinesias occur when a dopaminergic drug is manifesting its greatest central effect (peak dose dyskinesia), or less commonly, at the beginning and end of the central effect (biphasic dyskinesia). Choreiform dyskinesias, irrespective of their temporal pattern of occurrence, tend not to persist or emerge during sleep and are seldom the cause of self-reported sleep disturbance. Dystonic dyskinesias, on the other hand, are more likely to impact sleep. Although dystonia can also occur in untreated Parkinson disease patients, it is more commonly related to the administration of dopaminergic medications. Dystonic dyskinesias can occur with the peak effect of dopaminergic agents or in a biphasic pattern but even more commonly appear at the end of an interdose period when the central effects of medication have nearly or totally worn off (ie, on awakening in the morning after a night-long, medication-free interval). During this pattern of occurrence, referred to as early morning dystonia, painful plantar flexion of the feet and curling of the toes is typical. Less commonly, facial and upper extremity musculature are also affected.
Levodopa-induced myoclonus occurs predominantly, but not exclusively, at night. It typically involves axial and proximal muscles and can appear during non-REM sleep as often as 30 times per night. These movements usually emerge only after chronic administration of levodopa. It is not always clear whether they interrupt the sleep of the Parkinson disease patient, but they can pose a problem for the bed partner.
Akathisia, an irresistible internal desire to move, is seen in some Parkinson disease patients receiving levodopa and, rarely, in the untreated patient. It can be distinguished from restless legs syndrome by its lack of relationship to recumbency, the absence of associated sensory phenomena, and the involvement of the entire body. Although not completely confined to bedtime, it is commonly nocturnal in Parkinson disease patients. Akathisia has a variable relationship to the timing of levodopa administration and can occur in either the "on" or "off" state. Accordingly, in treating Parkinson disease patients with severe nocturnal akathisia it is sometimes necessary to experiment by first increasing and then decreasing the evening dosage of dopaminergic medication. Should both approaches fail, a bedtime dosage of the atypical neuroleptic clozapine may be effective in treating this symptom.
Excessive daytime sleepiness and Parkinson disease. Excessive daytime sleepiness (EDS) is common in Parkinson disease and is probably multifactorial (76; 129), occurring independently of nocturnal sleep disturbances (52). A quantitative EEG study suggests that daytime sleepiness in Parkinson disease patients is associated with a reduced overnight slow wave activity decline and reduced spindle frequency activity, indicating that poor sleep quality, with incomplete dissipation of homeostatic sleep pressure, may contribute to excessive daytime sleepiness in Parkinson disease (98). On the other hand, several risk factors for excessive daytime sleepiness in Parkinson disease have been demonstrated, such as male gender, the severity of the disease, presence of depression and/or cognitive impairment, hallucinations, dysautonomia, and the dose of dopamine agonists (102; 129; 34). In a cohort of 186 participants with Parkinson disease, no significant relationship between chronotype and sleepiness was found (68). Longitudinally, excessive daytime sleepiness in Parkinson disease has been associated with non-tremor dominant phenotype and the presence of autonomic dysfunction, depression, anxiety, and probable REM sleep behavior disorder (02; 121). To date, conflicting results regarding the higher prevalence of excessive daytime sleepiness in de novo Parkinson disease patients are present. A study on 159 drug-naïve patients found a higher prevalence of excessive daytime sleepiness in Parkinson disease compared to healthy controls at disease onset as well as during follow-up (110). On the contrary, a case-control study on a large cohort of Parkinson disease patients demonstrated that the prevalence of daytime sleepiness in de novo patients was not dissimilar to that of healthy controls (102).
Fatigue appears to be a separate symptom in Parkinson patients that is unrelated to daytime sleepiness or nighttime sleep dysfunction and is found in up to one third of patients with Parkinson disease.
Sleep-disordered breathing. A review of case-control polysomnographic studies on Parkinson disease patients highlighted the lack of consistency of the data regarding this topic (76; 107). Significant respiratory dysfunction is not seen in mild Parkinson disease. A polysomnographic study of Parkinson disease patients of all severities revealed a similar incidence of obstructive sleep apnea (OSA) in Parkinson disease and controls (112). If present, obstructive sleep apnea is associated with sleepiness, cognitive dysfunction, and higher baseline MDS-UPDRS scores (64; 63).
Obstructive sleep apnea severity is lower in Parkinson disease patients with REM sleep behavior disorder and with higher levodopa equivalent dose (100).
Obstructive sleep apnea is much more common in multiple system atrophy than in idiopathic Parkinson disease, and stridor is not seen in the latter condition.
Medications and excessive daytime sleepiness. Most of the commonly used antiparkinson medications, including levodopa, amantadine, dopamine agonists, COMT inhibitors, and anticholinergic agents have some potential to induce excessive daytime somnolence. Selegiline, on the other hand, is virtually never associated with excessive daytime sleepiness. Among the antiparkinson drugs, levodopa and dopamine agonists are the most common cause of medication-related somnolence (29). Typically, patients complain of an irresistible desire to sleep within 30 minutes of a dosage of standard or sustained release carbidopa-levodopa. Polysomnographic studies in such patients have demonstrated diurnal NREM sleep episodes after 30 to 60 minutes of a dosage of levodopa (23). Multiple sleep latency tests in these patients have been normal, whereas visual reaction times worsened after 30 and 60 minutes after levodopa intake (23). The pathogenesis of this phenomenon is unclear. Some excessive daytime somnolence in Parkinson disease undoubtedly occurs independent of medications, reflecting microstructural changes in the sleep-related circuits (06), but the striking temporal relationship between somnolence and the administration of the last dosage of medication in some patients suggests that, at least in these circumstances, a true cause-effect relationship exists. Unlike somnolence, fatigue does not appear to be related to therapy with dopamine agonists or levodopa, but it is said to be the single most common reason cited for medical disability insurance claims.
A potentially dangerous form of somnolence leading to serious motor vehicle accidents has been reported in patients being treated with dopaminergic medications, most commonly reported in patients receiving dopamine agonists such as pramipexole or ropinirole (36). Because of the suddenness of sleep onset in some cases, these episodes are sometimes labeled "sleep attacks." It was demonstrated using a maintenance of wakefulness test that increased use of dopamine agonists was associated with decreased alertness; however, increased levodopa doses actually were associated with higher levels of alertness (13). The International Parkinson and Movement Disorders Society Rating Scale Task Force has endorsed several instruments for measuring sleep and alertness in the Parkinson disease population (42). Among these self-reported instruments, Parkinson Disease Sleep Scale (PDSS) correlated well with Pittsburgh Sleep Quality Index (PSQI) and sleep diary-reported metrics (106).
Mood disorders and sleep in Parkinson disease. The behavioral manifestations of Parkinson disease can also impact sleep. Depression or anxiety symptoms are significantly associated with poor sleep quality in Parkinson disease (18). Depression occurs in over 40% of Parkinson disease patients, and these individuals have a higher incidence of sleep complaints than those who are not depressed. The typical clinical and polygraphically defined sleep changes caused by depression (including shortened REM sleep latency, increased number of arousals, and early awakening) occur more frequently in depressed than nondepressed Parkinson disease patients. The relative contributions of depression to disturbed sleep can be difficult to separate from the other effects of Parkinson disease. Some studies have suggested that within this population, age, illness-related variables and levodopa dose are more strongly correlated with sleep disturbance than the degree of depression. Others have found that depression correlates with sleep disturbance more than any motor or demographic variable of Parkinson disease. Dementia, another common behavioral manifestation of Parkinson disease, can indirectly impact sleep. Cognitively impaired Parkinson disease patients are much more susceptible to nocturnal confusion and hallucinations.
Circadian rhythms and Parkinson disease. Disruption of normal circadian rhythms is another potential effect of Parkinson disease on sleep (69). Reversal of the sleep cycle is common in Parkinson disease, especially in elderly patients with advanced disease. Typically, affected patients nap frequently during the day and are awake at night. This circadian abnormality is multifactorial in origin. Many of the standard external markers of diurnal rhythmicity, such as mealtime and scheduled activities, are altered by Parkinson disease and the timing of medications used to treat the condition. Often, a natural circadian pattern of worsening and improvement in dopamine-dependent functions may dictate certain periods of the waking day when the patient is ambulatory and active (typically the early morning) and other times when there is relative immobility and a tendency to nap (typically late afternoon).
In addition, it is possible that there is intrinsic pathology contributing to this dysfunction, with the primary circadian pacemaker and the suprachiasmatic nucleus being directly affected by the disease. It has been demonstrated that melatonin, a biological marker of the circadian system, shows decreased amplitude in Parkinson disease patients compared to controls, with the greatest differences seen in patients with Parkinson disease and excessive daytime sleepiness (116). In addition, the presence of alterations in body core temperature profile, another circadian marker, in Parkinson disease patients is still controversial (77; 128). Finally, studies have demonstrated that bright light therapy, often used to reset the circadian clock, can improve motor symptoms in Parkinson disease and subjective sleep quality (92); however, the appropriate timing and duration of light are still being determined. A deeper understanding of the dysfunctions of the networks governing circadian rhythms will provide not only a greater understanding of Parkinson disease neuropathology but will also hold the promise for effective therapies (38).
Parasomnias. Parkinson disease patients experience abnormal motor activity and behaviors (parasomnias) during sleep, with the most common being REM sleep behavior disorder (05).
Little is known about the time course of REM sleep behavior disorder in Parkinson disease. In a prospective study on moderate-to-advanced Parkinson disease patients, despite the subjective improvement of REM sleep behavior disorder symptoms in one-fourth of patients, REM sleep without atonia (RSWA) increased significantly at 3-years follow-up, correlating with the clinical evolution of motor and nonmotor symptoms (39). In another study, REM sleep without atonia is associated with an increased and more symmetric presentation of upper limb rigidity in mild to moderate Parkinson disease (54). One study underlines a significant association between doses of levodopa and REM sleep behavior disorder symptoms in Parkinson disease patients (62).
Several reports have strengthened the notion that patients presenting with isolated REM sleep behavior disorder (iRBD) often develop a progressive neurodegenerative disease involving α-synuclein pathology, including Parkinson disease, later in life (80; 65). A multicenter longitudinal study assessed the risk of developing a synucleinopathy in a cohort of 279 patients with iRBD, finding a relative risk of 25% after three years and 41% after five-years follow-up (79). A detailed meta-analysis showed that the appearance of significant motor dysfunction, constipation, orthostatic hypotension, hyposmia, mild cognitive impairment, and abnormal color vision in patients with iRBD correlated with susceptibility to Parkinson disease (117).
In addition, a controlled study conducted on 113 Parkinson disease patients demonstrated that REM sleep behavior disorder increases with disease duration, and it may be preceded by prodromal REM sleep behavioral events (104). The appearance of REM sleep behavior disorder in currently diagnosed Parkinson disease patients is associated with a high risk of developing visual hallucinations, dementia (28), impulse control disorders (17), and functional dependency (50), with a worse prognosis (35). Comparing 25 Parkinson disease patients with REM sleep behavior disorder and 25 Parkinson disease patients without REM sleep behavior disorder, patients with REM sleep behavior disorder had significant impairment in mini mental state examination category fluency test (FAS test), frontal assessment battery, attention (digit span backwards, Corsi span), verbal memory (story recall), and Rey's auditory verbal learning test (45; 27). In the de novo Parkinson disease-RBD group, impairment in global cognition, phonemic fluency, processing speed, and visuospatial function are associated with atrophy in the bilateral putamen, left hippocampus, left amygdala, and thinning in the right superior temporal gyrus (72). REM sleep behavior disorder in Parkinson disease is also associated with isolated apathy and increased severity of depressive symptoms (08).
Although REM sleep parasomnias have been extensively described in Parkinson disease, little is known about NREM parasomnias in Parkinson disease (55). A questionnaire study on 661 Parkinson disease patients showed a sleepwalking occurrence of 1.8 % and a night terrors occurrence of 3.9 % (124).
Periodic limb movements of sleep and restless legs syndrome. Periodic limb movements of sleep can be seen in up to 58% of Parkinson disease patients and they increase with increasing disease severity (103). Periodic limb movements of sleep consist of stereotypic movements of the lower extremities characterized by extension of the great toe as well as ankle and flexion at the knee and sometimes the hip. Rarely, the upper extremities are involved. SPECT of the dopamine transporter has suggested that periodic limb movements of sleep frequency in Parkinson disease correlates with striatal dopaminergic dysfunction.
Although the relationship between restless legs syndrome and Parkinson disease is still under debate and the pathophysiological link is still unclear (12), the association between these two disorders is common (88). As compared to non-parkinsonian patients, patients with Parkinson disease have been found to have onset of restless legs syndrome at an older age, and they are less likely to have a family history of the syndrome (88; 120). Furthermore, the syndrome has been associated with lower ferritin levels also in patients with Parkinson disease. A longitudinal study has demonstrated that restless legs syndrome is present in drug-naïve Parkinson disease patients at the time of the first diagnosis (4.6%) and that its prevalence increases during follow-up (6.5% at 2 years; 16.3% at 4 years) (67). Restless legs syndrome prevalence was higher in female (13%) than in male Parkinson disease patients (11%) and among patients who had previously received Parkinson disease treatment (15%) than among drug-naïve patients (11%) (123). Parkinson disease patients with restless legs syndrome suffer from worse life and sleep quality, depression, anxiety, and autonomic disturbances (125).
Effect of sleep on Parkinson disease. Sleep typically has a salutary effect on the symptoms of Parkinson disease. The most common diurnal pattern of symptom severity in Parkinson disease is that of improvement of akinesia and rigidity in the morning just after arising paralleled by improvement in nonmotor dopamine-dependent functions at the same time. In a questionnaire-based study, 6.9% of Parkinson disease patients reported improvement in symptoms following nocturnal sleep (113). Sleep benefit was more common in patients with longer disease duration, with shorter total sleep time and longer sleep latency (101). Better objective sleep measures were significantly associated with shorter low morning mobility (49). The beneficial effect of sleep on the symptoms of Parkinson disease can be so prominent in some patients as to eliminate the need for antiparkinsonian medications for the first half of the day. The mechanisms underlying this phenomenon are not yet fully understood. In addition to the salutary effect of sleep on the motor signs of Parkinson disease, there is additional evidence that lack of quality sleep is associated with impaired executive function, but not memory, in apparently non-demented Parkinson disease patients.
Clinical vignette
A 57-year-old man with a two-year history of Parkinson disease was initially treated with pramipexole in a dosage of 1 mg three times daily with good relief of his symptoms of asymmetric upper extremity tremor, mild generalized bradykinesia, and moderate rigidity of both arms and both legs. His wife complained that he frequently shouted out at night and grabbed her arm as though wrestling with her while he was still asleep. A clinical diagnosis of Parkinson disease-associated REM sleep behavior disorder was made and the patient was treated with clonazepam 0.5 mg at bedtime. This resulted in total resolution of these nocturnal episodes. Over the next five years, the motor symptoms of Parkinson disease progressed, requiring the addition of sustained-release carbidopa or levodopa, which he took in dosage of 50/200 at 8:00 AM, 12:00 PM, 6:00 PM, and 11:00 PM (bedtime). He soon began to develop vivid dreams and nocturnal hallucinations. Accordingly, his bedtime dosage of carbidopa-levodopa was discontinued, resulting in resolution of the nocturnal hallucinations. Without this bedtime dosage, he became severely immobile at night and was unable to shift position or arise to void despite a full bladder. He was restarted on a smaller dosage of sustained-release levodopa at bedtime, in addition to a bedtime dosage of 50 mg quetiapine. On this regime he was less akinetic during the night, yet he did not suffer from nocturnal hallucinosis.
Biological basis
Etiology and pathogenesis
The sleep disturbances experienced by Parkinson disease patients are multifactorial. It is known that Parkinson disease can affect sleep through disruption of micro- and macro-sleep architecture (81). Whole-night video polysomnography-high-density EEG (vPSG-hdEEG) suggests an association between sleep and some clinical phenotypes of Parkinson disease and a relationship between sleep disruption and levodopa-induced dyskinesia (04).
In a patient receiving antiparkinson drug therapy, it is often difficult to determine whether this disruption represents a primary neurobiological or a medication effect of Parkinson disease.
Two additional mechanisms by which sleep may be disturbed in Parkinson disease are the disruption of circadian rhythms and the appearance of parasomnias.
The appearance of a parasomnia, especially REM sleep behavior disorder, may antedate the onset of clinically apparent Parkinson disease (79; 14). In idiopathic REM sleep behavior disorder subjects, CD4+ T cells exhibit a peculiar molecular signature strongly resembling cells from Parkinson disease patients (26). Furthermore, α-synuclein (SNCA) hypomethylation in leukocytes existed both in patients with iRBD and those with Parkinson disease, indicating that α-synuclein methylation could be a potential biomarker for early Parkinson disease diagnosis (127).
The motor symptoms of Parkinson disease have significant potential to interrupt sleep. In this regard, either hyperkinetic or hypokinetic abnormalities can interfere with sleep onset or maintenance. One final mechanism of sleep disturbance relates to the medications used to treat Parkinson disease. These drugs can result in daytime sleepiness and nocturnal or early morning dystonia as well as contribute to the development of nocturnal hallucinations.
Dopamine deficiency is a major neurochemical change in Parkinson disease. Generally, dopaminergic stimulation is thought to promote wakefulness. Dopamine agonists have been found to suppress REM sleep in animals (111). However, single-cell recordings in nigral dopaminergic neurons do not exhibit major changes during the phases of the sleep-wake cycle (66). Observations such as these raise the possibility that other neurotransmitter changes in Parkinson disease may play a role in the genesis of sleep disorders. Moreover, alterations in brainstem nuclei, ie, coeruleus-subcoeruleus and gigantocellularis, that are present in Parkinson disease patients could explain the presence of REM behavior disorder. MRI studies document a smaller right putamen, left hippocampus, and left thalamus volume linked to REM sleep behavior disorder symptoms severity in Parkinson disease patients (47).
Norepinephrine and serotonin are both reduced in Parkinson disease (109). In a study with positron emission tomography, reduced serotonergic function in the midbrain raphe, basal ganglia, and hypothalamus was associated with sleep dysfunction in Parkinson disease (119).
Neuromelanin-sensitive imaging demonstrated reduced signal intensity in the locus coeruleus/subcoeruleus area that correlated with the percentage of abnormally increased muscle tone during REM sleep (40). Hypocretin cell loss has been demonstrated in the hypothalamus of Parkinson patients, CSF hypocretin has been found to be normal, reinforcing the notion that other mechanisms may contribute to excessive somnolence in this condition (21). Aberrations of cholinergic function in Parkinson disease may be important in the production of sleep disorders. The pedunculopontine nucleus contains cholinergic neurons that are thought to play an important role in the modulation of REM sleep, has reciprocal connections with the substantia nigra, and is known to be hyperactive in animal models of parkinsonism (74). Studies looking at PET imaging for cholinergic neurons found evidence of cholinergic denervation in patients with symptoms of REM sleep behavior disorder (51). Therefore, abnormalities of cholinergic function may be, in part, responsible for the increased incidence of REM sleep behavior disorder as well as for the disruption of sleep architecture found in patients with Parkinson disease. In Parkinson disease patients with excessive daytime sleepiness, current neuroimaging studies generally suggest diminished neural structural and functional features (eg, brain volume, white matter integrity as indicated by fractional anisotropy, and cerebral metabolism) (118). Sleep disturbances were associated with thalamic atrophy in 41 Parkinson disease patients, and an alteration of intra- and interregional functional connectivity of the anterior cingulate gyrus was related to sleep disorders in patients with tremor-dominant Parkinson disease (19; 71). Parkinson disease patients with nocturnal hallucinations have prominent basal ganglia volume reduction (83).
Parkinson disease patients with REM sleep behavior disorder show extensive cortical thinning in the perisylvian and temporal cortices and shape contraction in the basal ganglia, hippocampus, and thalamus, suggesting more severe neurodegeneration (47; 84).
Epidemiology
Although there are some exceptions, sleep disorders associated with Parkinson disease tend to be more common and intense in older patients and in those with more severe clinical symptoms. With the exception of REM sleep behavior disorder, sleep disorders associated with Parkinson disease tend to occur later rather than earlier in the course of the illness.
Prevention
To date, there are no proven means of delaying the onset or halting the progression of Parkinson disease. Once the illness is established, however, several strategies may be used to reduce the incidence of associated sleep disorders. Among these strategies including also a correct sleep-hygiene, is the judicious use of antiparkinsonian drugs, which includes:
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(a) the use of those drugs with the least potential for producing daytime somnolence | |
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(b) avoiding bedtime dosages of medications if not needed to reverse nocturnal immobility or tremor | |
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(c) low dosages of dopaminergic drugs in order to reduce the incidence of dyskinesias and hallucinosis (91) |
Diagnostic workup
The correct use of antiparkinsonian drugs, with a successful balance between side-effects and motor symptoms, is fundamental to reduce drug-related alterations of sleep in Parkinson patients. Thus, the improvement in daytime somnolence after replacing one dopaminergic medication with another confirms drug-induced somnolence. Improvement in nocturnal sleep efficiency after adding a dosage of sustained-release levodopa at bedtime helps confirm insomnia secondary to nocturnal rigidity and akinesia. Still, many forms of sleep disturbance require documentation by formal testing. RBD current diagnosis relies on nocturnal video-polysomnography; the use of wrist actigraphy could be of help in RBD diagnoses in home settings (85).
Suspected sleep apnea should be assessed by formal polysomnography, as should insomnia and daytime somnolence that cannot be adequately diagnosed by the practical measures mentioned previously. For Parkinson disease patients with severe daytime somnolence, a 24-hour sleep/wake polygraphic recording could be useful to document the severity of this symptom. In some patients, documenting the relationship of daytime somnolence to medication dosing times is also beneficial. Additionally, these tests can be useful to document treatment success.
Management
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• Park sleep, originally identified by Sauerbier and colleagues in 2016, is one of the non-motor Parkinson disease clinical subtypes characterized by the predominant clinical presentation of sleep dysfunctions including excessive daytime sleepiness and insomnia (94). | |
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• Park sleep recognition may drive lifestyle changes (eg, driving) along with therapy adjustments, as Park sleep patients may be sensitive to dopamine D3 active agonists, such as ropinirole and pramipexole (108). | |
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• If the nature of the sleep disturbance can be correctly identified, there is an excellent chance that a beneficial therapeutic intervention can be undertaken. | |
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• Levodopa and dopaminergic drugs may have different effects, beneficial or adverse, depending on dosing, method of administration, and differential effects on the different dopamine receptors (95). |
If the nature of the sleep disturbance can be correctly identified, there is an excellent chance that a beneficial therapeutic intervention can be undertaken.
Patients whose sleep is interrupted by extreme nocturnal rigidity benefit therapeutically from a bedtime dose of a dopaminergic agent with a relatively long efficacy half-life. A sustained-release levodopa preparation is possibly more useful. The use of a COMT-inhibiting agent along with levodopa at bedtime might further prolong the dopaminergic effect during the night. Bedtime dosing in these patients results in fewer awakenings, at least during the early part of the night and often through the entire night. Some patients may require an additional dose of a sustained-release or standard levodopa preparation after early awakening to allow uninterrupted sleep for the remainder of the night. Dopaminergic drugs can also interfere with sleep by impairing sleep initiation or by inducing nocturnal dyskinesias or hallucinations in some patients. Bedtime dosing with dopaminergic medications can either improve or interfere with sleep. A clinical judgment in individual patients must be made to determine which effect is likely to prevail. In general, advanced Parkinson disease patients who experience nocturnal emergence of motoric symptoms are more likely to benefit from bedtime dosing. Rotigotine, a dopamine agonist administered through a 24-hour transdermal patch (16), or the administration of 24-hour prolonged-release dopamine agonist can be useful in providing some relief of sleep-disturbing motor symptoms during the entire night. Rasagiline (1 mg/day) showed beneficial effects on sleep quality as polysomnographically measured (99), and safinamide improved nocturnal sleep disturbances and daytime sleepiness as assessed by sleep questionnaires in fluctuating Parkinson disease patients (53). In patients with advanced Parkinson disease with moderate to severe insomnia (Insomnia Severity Index score ≥15), subcutaneous night-time only apomorphine infusion improved sleep disturbances according to difference on PDSS score, with an overall safety profile (25).
In patients who are severely disabled by nocturnal symptoms, but unable to get sufficient relief from these medical measures, deep brain stimulation of the subthalamic nucleus can provide good results (20; 87; 24; 44). Of interest, daytime sleepiness does not necessarily change after deep brain stimulation despite significant reduction of parkinsonian medications (56). Early morning dystonia can also be improved with bilateral deep brain stimulation (56). It remains elusive whether modulated activity in the subthalamic nucleus directly contributes to changes in sleep-wake behavior (10). Although it is possible that the procedure has a direct effect on sleep regulatory centers, much of the benefit can be explained by the improvement of nocturnal motor symptoms and the reduction in dosage of antiparkinsonian medications.
When insomnia is not related to motor or nonmotor Parkinson symptoms, eszopiclone, doxepin, zolpidem, trazodone, and ramelteon could be useful, although these drugs are investigational in Parkinson disease because the evidence of their efficacy is insufficient (89; 91). Melatonin can significantly improve the subjective and objective sleep quality of patients with Parkinson disease with good safety and tolerability (58).
In addition to pharmacological treatment of the sleep-disrupting motor features of Parkinson disease, several nonpharmacological strategies are also useful. To minimize the effect of nocturnal immobility, the use of satin sheets can be recommended as a means of reducing friction between the body and bed sheets, thereby allowing easier mobility in bed. Ambient stimuli (noises, drafts, a restless bed partner), which might lead to brief arousals followed by a major reemergence of tremor or rigidity and pain, should be avoided to the extent possible. Light-intensity exercise rehabilitation may be helpful in ameliorating the quality of sleep, as well as mood and cognition (86; 03).
Depression-related sleep disturbances in Parkinson disease are treated in much the same manner as those in the non-Parkinson disease population. The only minor differences include choices of drug. The sedating antidepressants such as amitriptyline or doxepin administered at bedtime are useful for this purpose. A randomized controlled trial demonstrated that doxepin (10 mg) at bedtime significantly improved both insomnia severity and sleep quality (89). For some Parkinson disease patients, especially those with dementia, agents with lower anticholinergic properties such as nortriptyline are a better choice in order to avoid exacerbating their cognitive deficit. Selective serotonin reuptake inhibitor (SSRI) drugs may be effective in treating depression and sleep-related symptoms in Parkinson disease (22). Also, the use of either SSRI or tricyclic antidepressants in patients receiving selegiline or rasagiline for Parkinson disease can cause a potentially serious interaction in a very small number of patients. Agomelatine in Parkinson disease depressed patients may have a considerable therapeutic potential because of its dual action for treating both symptoms of depression and disturbed sleep, reducing extrapyramidal symptoms (07).
Several strategies are available to help reverse the sleep cycle towards normalcy in Parkinson disease. An attempt should be made to restore mealtime to a typical morning, noon, and early evening pattern. Scheduled activities should be planned during times of predicted somnolence, whether drug-induced or related to the patient's spontaneous diurnal cycle. Light exposure is a promising medical treatment for improving sleep in Parkinson disease patients receiving dopaminergic therapies (60; 31). After exposing patients with Parkinson disease to bright or dim-red light twice daily, sleep and depressive symptoms improved, daytime sleepiness decreased, and Parkinson-specific motor scores were reduced (115; 105). New approaches include the prescription of precision medicine to modulate photoreceptor activation ratios that reflect daylight inputs to the circadian pacemaker, the use of small molecules to target clock genes, and the manipulation of orexin pathways that could help restore the circadian system, to offer novel symptomatic and novel disease modifying strategies (33).
The sedating effects of antiparkinson medication can be countered to a slight extent by administration of a daytime dosage of selegiline. Despite the lack of clear evidence of the effect of pharmacological treatment of excessive daytime sleepiness in Parkinson disease patients (90), stimulant agents such as methylphenidate or dextroamphetamine are occasionally used, but tachyphylaxis and the occasional induction of hallucinosis in the elderly or cognitively impaired Parkinson disease patient limit their use. The adverse behavioral effects of these wake-promoting drugs in Parkinson disease might be avoided through the use of modafinil, which appears to have little or no dopaminergic activity and to reduce daytime sleepiness and fatigue (30). Early reports of the usefulness of this agent in Parkinson disease patients were favorable, but a double-blind study suggested that this agent was no different than placebo in improving excessive daytime sleepiness in Parkinson patients (73). Sodium oxybate was found to be useful in enhancing slow-wave sleep as well as in reducing daytime somnolence and fatigue (15).
Medication-induced somnolence can be difficult to correct. One simple strategy is to lower the daily dose. Another, mentioned earlier, is to alter environmental stimuli and planned activity schedules in the immediate post-dose period when somnolence is most likely to occur. During this at-risk period, dark, quiet, poorly ventilated rooms should be avoided, and planned vigorous activities such as a morning or afternoon walk should be scheduled. Fortunately, many Parkinson disease patients are best able to engage in such physically demanding activities immediately after a dosage of medication, when they are "on." An attempt can also be made to change to another antiparkinson drug. Some patients may be less somnolent on standard carbidopa or levodopa than on the sustained-release preparation. In a small percentage of patients, the reverse is true. Similarly, the available dopamine agonists may each have different potential to induce somnolence or “sleep attacks” in a given patient, so changing from one agent to another is a reasonable strategy. Reducing the agonist dosage, if clinically feasible, is also an effective strategy for many patients. Lastly, stimulant drugs, especially modafinil, have sometimes been found to be useful to combat this form of excessive daytime sleepiness in Parkinson disease.
Drug-induced hallucination treatment begins with a systematic withdrawal of dopaminergic drugs, beginning with the least clinically potent agents such as anticholinergics, amantadine, and selegiline. Next, a reduction or discontinuation of levodopa and dopamine agonists may be considered, although it is not always possible because of reemergence of serious parkinsonian symptoms. In this case, a relatively small bedtime dosage of the atypical antipsychotic agent quetiapine could be used. Quetiapine also improved sleep in Parkinson disease patients without hallucinations or psychosis, whereas two other atypical antipsychotic agents, olanzapine and risperidone, seem to be less effective for this purpose because they retain some ability to worsen Parkinson disease. If these strategies fail, low dosages of the atypical neuroleptic clozapine (12.5 to 50 mg per day) can be administered. Both of these agents can cause daytime somnolence if taken at any time other than at bedtime. Clozapine must be used with caution because of its potential to induce agranulocytosis and request periodic controls of blood-cell counts.
Because nocturnal or early morning dystonia is most commonly related to the waning central effect of the previous dosage of levodopa as the night progresses, the most useful treatment is to institute bedtime therapy with a relatively long-acting dopaminergic agent such as controlled release carbidopa-levodopa or a long-acting dopamine agonist. In some patients, a bedtime dosage of baclofen will also ameliorate this symptom. An additional strategy employed by some patients to prevent early morning dystonia is to set their alarm so that they can administer a dose of levodopa 30 to 45 minutes earlier than their usual waking time and then return to sleep to awaken permanently after the medication has begun to take effect.
Because of the potential for serious injury to the patient and for disruption of both the patient's and bed partner's sleep, serious attention should be given to treating REM sleep behavior disorder in Parkinson disease. The potential for injury while acting out a dream is even greater than average in Parkinson disease patients because they may fall if they attempt to stand in the middle of the night when antiparkinsonian medications have worn off. Parkinson disease patients with REM sleep behavior disorder are treated in much the same way as in non-Parkinson disease patients, namely clonazepam, at bedtime (43). Because of the long efficacy half-life of clonazepam, a bedtime dosage can result in daytime somnolence. Accordingly, it is often useful to experiment with dosage times as far in advance of bedtime as possible in order to avoid this potential complication. Melatonin improves sleep quality in patients with neurodegenerative disorders and can be considered as a possible mono or add-on therapy in patients with REM sleep behavior disorder (126; 01). Nevertheless, in a study on 30 Parkinson disease patients with REM sleep behavior disorder, prolonged-release melatonin 4 mg did not reduce REM sleep behavior disorder (41). Ramelteon was effective in REM sleep behavior disorder in Parkinson disease patients in two open trials, which were conducted in 24 and 12 Parkinson disease patients, respectively (32). Daytime sleepiness, nausea, delirium, giddiness, and worsening of constipation are possible ramelteon side effects.
In patients with obstructive sleep apnea, CPAP treatment can improve overall nonmotor symptoms, sleep quality, and global cognitive function (46).
Outcomes
Many of the sleep disturbances associated with Parkinson disease are amenable to reversal, although others are not. Conditions such as insomnia related to nocturnal immobility, nocturnal hallucinosis, and REM sleep behavior disorder can often be reversed with appropriate therapeutic interventions. Daytime somnolence has the worst prognosis for improvement, especially when related to medication. Often, patients suffering this adverse effect note that virtually all of the dopaminergic medications act similarly to induce somnolence, although discontinuing all dopaminergic medications during the day is not a viable option for most of these patients.
Special considerations
Pregnancy
Pregnancy is rare in the Parkinson disease population, given the older age distribution of the condition.
Anesthesia
Parkinson disease may be temporarily exacerbated after a major surgical procedure, especially with the use of general anesthesia or major sedation.
Media
References
- 01
- Ahn JH, Kim M, Park S, et al. Prolonged-release melatonin in Parkinson’s disease patients with a poor sleep quality: a randomized trial. Parkinsonism Relat Disord 2020;75:50-4. PMID 32480307
- 02
- Amara AW, Chahine LM, Caspell-Garcia C, et al. Longitudinal assessment of excessive daytime sleepiness in early Parkinson’s disease. J Neurol Neurosurg Psychiatry 2017;88:(8):653-62. PMID 28554959
- 03
- Amara AW, Wood KH, Joop A, et al. Randomized, controlled trial of exercise on objective and subjective sleep in Parkinson’s Disease. Mov Disord 2020;35(6):947-58. PMID 32092190
- 04
- Amato N, Manconi M, Möller JC, et al. Levodopa-induced dyskinesia in Parkinson disease: sleep matters. Ann Neurol 2018;84(6):905-17. PMID 30328147
- 05
- American Academy of Sleep Medicine. International classification of sleep disorders: 3rd edition, text revision. Darien, IL: American Academy of Sleep Medicine, 2023.**
- 06
- Ashraf-Ganjouei A, Kheiri G, Masoudi M, et al. White matter tract alterations in drug-naïve Parkinson’s disease patients with excessive daytime sleepiness. Front Neurol 2019;10:378. PMID 6477886
- 07
- Avila A, Cardona X, Martin-Baranera M, et al. Agomelatine for depression in Parkinson Disease: additional effect on sleep and motor dysfunction. J Clin Psychopharmacol 2015;35(6):719-23. PMID 26444951
- 08
- Bargiotas P, Ntafouli M, Lachenmayer ML, Krack P, Schüpbach WMM, Bassetti CLA. Apathy in Parkinson’s disease with REM sleep behavior disorder. J Neurol Sci 2019;399:194-8. PMID 30826716
- 09
- Barone P, Antonini A, Colosimo C, et al. The PRIAMO study: a multicenter assessment of nonmotor symptoms and their impact on quality of life in Parkinson’s disease. Mov Disord 2009;24(11):1641-9.** PMID 19514014
- 10
- Baumann-Vogel H, Imbach LL, Sürücü O, et al. The impact of subthalamic deep brain stimulation on sleep-wake behavior: a prospective electrophysiological study in 50 Parkinson patients. Sleep 2017;40(5). PMID 28369624
- 11
- Bhidayasiri R, Trenkwalder C. Getting a good night sleep? The importance of recognizing and treating nocturnal hypokinesia in Parkinson's disease. Parkinsonism Relat Disord 2018;50:10-8. PMID 29336905
- 12
- Bliwise DL, Karroum EG, Greer SA, Factor SA, Trotti LM. Restless legs symptoms and periodic leg movements in sleep among patients with Parkinson's disease. J Parkinsons Dis 2022;12(4):1339-44. PMID 35311713
- 13
- Bliwise DL, Trotti LM, Wilson AG, et al. Daytime alertness in Parkinson’s disease: potentially dose-dependent, divergent effects by drug class. Mov Disord 2012;27(9):1118-24. PMID 22753297
- 14
- Blesa J, Foffani G, Dehay B, Bezard E, Obeso JA. Motor and non-motor circuit disturbances in early Parkinson disease: which happens first? Nat Rev Neurosci 2022;23(2):115-28. PMID 34907352
- 15
- Büchele F, Hackius M, Schreglmann SR, et al. Sodium oxybate for excessive daytime sleepiness and sleep disturbance in Parkinson disease: a randomized clinical trial. JAMA Neurol 2018;75(1):114-8. PMID 29114733
- 16
- Calandra-Buonaura G, Guaraldi P, Doria A, et al. Rotigotine objectively improves sleep in Parkinson's disease: an open-label pilot study with actigraphic recording. Parkinsons Dis 2016;2016:3724148. PMID 26981312
- 17
- Cao R, Chen X, Xing F, Xie C, Hu P, Wang K. Cross-sectional and longitudinal associations between probable rapid eye movement sleep behavior disorder and impulse control disorders in Parkinson’s disease. Eur J Neurol 2020;27(5):757-63. PMID 32065438
- 18
- Chang CW, Fan JY, Chang BL, Wu YR. Anxiety and Levodopa equivalent daily dose are potential predictors of sleep quality in patients with Parkinson Disease in Taiwan. Front Neurol 2019;10:340. PMID 6476952
- 19
- Chen X, Hou X, Luo X, et al. Altered intra- and inter-regional functional connectivity of the anterior cingulate gyrus in patients with tremor-dominant Parkinson’s Disease complicated with sleep disorder. Front Aging Neurosci 2019;11:319. PMID 31824298
- 20
- Choi JH, Kim HJ, Lee JY, et al. Long-term effects of bilateral subthalamic nucleus stimulation on sleep in patients with Parkinson’s disease. PLoS ONE 2019;14(8):e0221219. PMID 31454366
- 21
- Compta Y, Santamaria J, Ratti L, et al. Cerebrospinal hypocretin, daytime sleepiness and sleep architecture in Parkinson's disease dementia. Brain 2009;132(Pt 12):3308-17. PMID 19858078
- 22
- Connolly BS, Lang AE. Pharmacological treatment of Parkinson disease: a review. JAMA 2014;311(16):1670-83. PMID 24756517
- 23
- Contin M, Provini F, Martinelli P, et al. Excessive daytime sleepiness and levodopa in Parkinson's disease: polygraphic, placebo-controlled monitoring. Clin Neuropharmacol 2003;26(3):115-8. PMID 12782912
- 24
- Dafsari HS, Ray-Chaudhuri K, Ashkan K, et al. Beneficial effect of 24-month bilateral subthalamic stimulation on quality of sleep in Parkinson’s disease. J Neurol 2020;267(6):1830-41. PMID 32152689
- 25
- De Cock VC, Dodet P, Leu-Semenescu S, et al. Safety and efficacy of subcutaneous night-time only apomorphine infusion to treat insomnia in patients with Parkinson's disease (APOMORPHEE): a multicentre, randomised, controlled, double-blind crossover study. Lancet Neurol 2022;21(5):428-37. PMID 35429481
- 26
- De Francesco E, Terzaghi M, Storelli E, et al. CD4+ T-cell transcription factors in Idiopathic REM Sleep Behavior Disorder and Parkinson’s Disease. Mov Disord 2021;36(1):225-9. PMID 32649001
- 27
- Dijkstra F, de Volder I, Viaene M, Cras P, Crosiers D. Polysomnographic predictors of sleep, motor, and cognitive dysfunction progression in Parkinson's Disease. Curr Neurol Neurosci Rep 2022;21(5):428-37. PMID 35994190
- 28
- Duarte Folle A, Paul KC, Bronstein JM, Keener AM, Ritz B. Clinical progression in Parkinson’s disease with features of REM sleep behavior disorder: A population-based longitudinal study. Parkinsonism Relat Disord 2019;62:105-11. PMID 6589360
- 29
- Eckhardt C, Fanciulli A, Högl B, et al. Analysis of sleep, daytime sleepiness and autonomic function and multiple system atrophy and Parkinson disease: a prospective study. J Clin Sleep Med 2023;19(1):63-71. PMID 36004744
- 30
- Elbers RG, Berendse HW, Kwakkel G. Treatment of fatigue in Parkinson disease. JAMA 2016;315(21):2340-1. PMID 27272586
- 31
- Endo T, Matsumura R, Tokuda IT, et al. Bright light improves sleep in patients with Parkinson’s disease: possible role of circadian restoration. Sci Rep 2020;10(1):7982. PMID 32409683
- 32
- Esaki Y, Kitajima T, Koike S, et al. An open-labeled trial of Ramelteon in idiopathic rapid eye movement sleep behavior disorder. J Clin Sleep Med 2016;12(5):689-93. PMID 26857053
- 33
- Feigl B, Lewis SJG, Rawashdeh O. Targeting sleep and the circadian system as a novel treatment strategy for Parkinson's disease. J Neurol 2023. [Epub ahead of print] PMID 37943299
- 34
- Feng F, Cai Y, Hou Y, Ou R, Jiang Z, Shang H. Excessive daytime sleepiness in Parkinson's disease: a systematic review and meta-analysis. Parkinsonism Relat Disord 2021;85:133-40. PMID 33637423
- 35
- Fereshtehnejad SM, Romenets SR, Anang JB, Latreille V, Gagnon JF, Postuma RB. New clinical subtypes of Parkinson disease and their longitudinal progression: a prospective cohort comparison with other phenotypes. JAMA Neurol 2015;72(8):863-73. PMID 26076039
- 36
- Ferreira JJ, Galitzky M, Montastruc JL, Rascol O. Sleep attacks and Parkinson’s disease treatment. Lancet 2000;355:1333-4. PMID 10776750
- 37
- Ferreira T, Prabhakar S, Kharbanda PS. Sleep disturbances in drug naïve Parkinson's disease (PD) patients and effect of levodopa on sleep. Ann Indian Acad Neurol 2014;17(4):416-9. PMID 25506163
- 38
- Fifel K. Alterations of the circadian system in Parkinson’s disease patients. Mov Disord 2017;32(5):682-92. PMID 27859638
- 39
- Figorilli M, Marques AR, Vidal T, et al. Does REM sleep behavior disorder change in the progression of Parkinson’s disease? Sleep Med 2020;68:190-8. PMID 32044557
- 40
- Garcia-Lorenzo D, Longo-Dos Santos C, Ewenczyk C, et al. The coeruleus/subcoeruleus complex in rapid eye movement sleep behaviour disorders in Parkinson’s disease. Brain 2013;136(Pt 7):2120-9. PMID 23801736
- 41
- Gilat M, Coeytaux Jackson A, Marshall NS, et al. Melatonin for rapid eye movement sleep behavior disorder in Parkinson’s disease: a randomised controlled trial. Mov Disord 2020;35(2):344-9. PMID 31674060
- 42
- Högl B, Arnulf I, Comella C, et al. Scales to assess sleep impairment in Parkinson's disease: critique and recommendations. Mov Disord 2010;25(16):2704-16. PMID 20931631
- 43
- Howell M, Avidan AY, Foldvary-Schaefer N, et al. Management of REM sleep behavior disorder: an American Academy of Sleep Medicine clinical practice guideline. J Clin Sleep Med 2023;19(4):759-68. PMID 36515157
- 44
- Jost ST, Ray Chaudhuri K, Ashkan K, et al. Subthalamic stimulation improves quality of sleep in Parkinson disease: a 36-month controlled study. J Parkinsons Dis 2021;11(1):323-35. PMID 33074192
- 45
- Kamble N, Yadav R, Lenka A, Kumar K, Nagaraju BC, Pal PK. Impaired sleep quality and cognition in patients of Parkinson’s disease with REM sleep behavior disorder: a comparative study. Sleep Med 2019;62:1-5. PMID 31518942
- 46
- Kaminska M, Mery VP, Lafontaine AL, et al. Change in cognition and other non-motor symptoms with obstructive sleep apnea treatment in Parkinson disease. J Clin Sleep Med 2018;14(5);819-28. PMID 29734988
- 47
- Kamps S, van den Heuvel OA, van der Werf YD, Berendse HW, Weintraub D, Vriend C. Smaller subcortical volume in Parkinson patients with rapid eye movement sleep behavior disorder. Brain Imaging Behav 2019;13(5):1352-60. PMID 30155787
- 48
- Kataoka H, Saeki K, Kurumatani N, Sugie K, Obayashi K. Objective sleep measures between patients with Parkinson’s disease and community-based older adults. Sleep Med 2020a;68:110-4. PMID 32035300
- 49
- Kataoka H, Saeki K, Yamagami Y, Sugie K, Obayashi K. Quantitative associations between objective sleep measures and early-morning mobility in Parkinson’s disease: cross-sectional analysis of the PHASE study. Sleep 2020b;43(1):zsz203. PMID 31554009
- 50
- Kim R, Yoo D, Im JH, Kim HJ, Jeon B. REM sleep behavior disorder predicts functional dependency in early Parkinson’s disease. Parkinsonism Relat Disord 2019;66:138-42. PMID 31371182
- 51
- Kotagal V, Albin RL, Müller ML, et al. Symptoms of rapid eye movement sleep behavior disorder are associated with cholinergic denervation in Parkinson disease. Ann Neurol 2012;71(4):560-8. PMID 22522445
- 52
- Liguori C, Mercuri NB, Albanese M, Olivola E, Stefani A, Pierantozzi M. Daytime sleepiness may be an independent symptom unrelated to sleep quality in Parkinson’s disease. J Neurol 2019;266(3):636-41. PMID 30607535
- 53
- Liguori C, Stefani A, Ruffini R, Mercuri NB, Pierantozzi M. Safinamide effect on sleep disturbances and daytime sleepiness in motor fluctuating Parkinson's disease patients: a validated questionnaires-controlled study. Parkinsonism Relat Disord 2018;57:80-1. PMID 30006034
- 54
- Linn-Evans ME, Petrucci MN, Amundsen Huffmaster SL, et al. REM sleep without atonia is associated with increased rigidity in patients with mild to moderate Parkinson’s disease. Clin Neurophysiol 2020;131(8):2008-16. PMID 32451296
- 55
- Loddo G, Fragiacomo F, Mainieri G, et al. Disorders of arousal in 4 older men: evidence from clinical practice. J Clin Sleep Med 2022;18(1):129-36. PMID 34180806
- 56
- Lyons KE, Pahwa R. Effects of bilateral subthalamic nucleus stimulation on sleep, daytime sleepiness, and early morning dystonia in patients with Parkinson’s disease. J Neurosurg 2006;104(4):502-5. PMID 16619652
- 57
- Lysen TS, Darweesh SKL, Ikram MK, Luik AI, Ikram MA. Sleep and risk of parkinsonism and Parkinson’s disease: a population-based study. Brain 2019;142(7):2013-22. PMID 31038176
- 58
- Ma H, Yan J, Sun W, Jiang M, Zhang Y. Melatonin treatment for sleep disorders in Parkinson's Disease: a meta-analysis and systematic review. Front Aging Neurosci 2022;14:784314. PMID 35185525
- 59
- Maggi G, Trojano L, Barone P, Santangelo G. Sleep disorders and cognitive dysfunctions in Parkinson's disease: a meta-analytic study. Neuropsychol Rev 2021;31(4):643-82. PMID 33779875
- 60
- Martino JK, Freelance CB, Willis GL. The effect of light exposure on insomnia and nocturnal movement in Parkinson's disease: an open label, retrospective, longitudinal study. Sleep Med 2018;44:24-31. PMID 29530365
- 61
- McCarter SJ, Camerucci E, Mullan AF, et al. Sleep disorders in early-onset parkinsonism: a population-based study. J Parkinsons Dis 2023;13(7):1175-83. PMID 37742659
- 62
- Meloni M, Bortolato M, Cannas A, et al. Association between dopaminergic medications and REM sleep behavior disorder in Parkinson’s disease: a preliminary cohort study. J Neurol 2020;267(10):2926-31. PMID 32472180
- 63
- Meng L, Benedetti A, Lafontaine AL, et al. Obstructive sleep apnea, CPAP therapy and Parkinson's disease motor function: a longitudinal study. Parkinsonism Relat Disord 2020;70:45-50. PMID 31855690
- 64
- Mery VP, Gros P, Lafontaine AL, et al. Reduced cognitive function in patients with Parkinson disease and obstructive sleep apnea. Neurology 2017;88(12):1120-8. PMID 28228566
- 65
- Miglis MG, Adler CH, Antelmi E, et al. Biomarkers of conversion to α-synucleinopathy in isolated rapid-eye-movement sleep behaviour disorder. Lancet Neurol 2021;20(8):671-84. PMID 34302789
- 66
- Miller JD, Farber J, Gatz P, Roffwarg H, German DC. Activity of mesencephalic dopamine and non-dopamine neurons across stages of sleep and walking in the rat. Brain Res 1983;273:133-41. PMID 6616218
- 67
- Moccia M, Erro R, Picillo M, et al. A four-year longitudinal study on restless legs syndrome in Parkinson disease. Sleep 2016;39(2):405-12. PMID 26564123
- 68
- Murphy S, Chibnik LB, Videnovic A. Chronotype, sleep, and sleepiness in Parkinson's disease. Parkinsonism Relat Disord 2023;106:105189. PMID 36442363
- 69
- Nassan M, Videnovic A. Circadian rhythms in neurodegenerative disorders. Nat Rev Neurol 2022;18(1):7-24.** PMID 34759373
- 70
- Nguy V, Barry BK, Moloney N, et al. The associations between physical activity, sleep, and mood with pain in people with Parkinson’s Disease: an observational cross-sectional study. J Parkinsons Dis 2020;10(3):1161-70. PMID 32333551
- 71
- Niccolini F, Wilson H, Giordano B, et al. Sleep disturbances and gastrointestinal dysfunction are associated with thalamic atrophy in Parkinson’s disease. BMC Neurosci 2019;20(1):55. PMID 31640554
- 72
- Oltra J, Uribe C, Segura B, et al. Brain atrophy pattern in de novo Parkinson's disease with probable RBD associated with cognitive impairment. NPJ Parkinsons Dis 2022;8(1):60. PMID 35610256
- 73
- Ondo WG, Fayle R, Atassi F, Jankovic J. Modafinil for daytime somnolence in Parkinson’s disease: double blind, placebo, controlled parallel trial. J Neurol Neurosurg Psychiatry 2005;76:1636-9. PMID 16291885
- 74
- Orieux G, Francois C, Feger J, et al. Metabolic activity of excitatory parafascicular and pedunculopontine inputs to the subthalamic nucleus in a rat model of Parkinson’s disease. Neuroscience 2000;97:79-88. PMID 10771341
- 75
- Parkinson J. An essay on the shaking palsy. London: Sherwood Neely and Jones, 1817.
- 76
- Peeraully T, Yong MH, Chokroverty S, Tan EK. Sleep and Parkinson's disease: a review of case-control polysomnography studies. Mov Disord 2012;27(14):1729-37.** PMID 23115083
- 77
- Pierangeli G, Provini F, Maltoni P, et al. Nocturnal body core temperature falls in Parkinson's disease but not in Multiple-System Atrophy. Mov Disord 2001;16(2):226-32. PMID 11295774
- 78
- Pierantozzi M, Placidi F, Liguori C, et al. Rotigotine may improve sleep architecture in Parkinson’s disease: a double-blind, randomized, placebo-controlled polysomnographic study. Sleep Med 2016;21:140-4. PMID 27448485
- 79
- Postuma RB, Iranzo A, Hogl B, et al. Risk factors for neurodegeneration in idiopathic rapid eye movement sleep behavior disorder: a multicenter study. Ann Neurol 2015;77(5):830-9.** PMID 25767079
- 80
- Postuma RB, Iranzo A, Hu M, et al. Risk and predictors of dementia and parkinsonism in idiopathic REM sleep behaviour disorder: a multicentre study. Brain 2019;142(3):744-59. PMID 30789229
- 81
- Priano L, Bigoni M, Albani G, et al. Sleep microstructure in Parkinson’s disease: cycling alternating pattern (CAP) as a sensitive marker of early NREM sleep instability. Sleep Med 2019;61:57-62. PMID 31307885
- 82
- Pushpanathan ME, Loftus AM, Thomas MG, Gasson N, Bucks RS. The relationship between sleep and cognition in Parkinson's disease: A meta-analysis. Sleep Med Rev 2016;26:21-32.** PMID 26365136
- 83
- Radziunas A, Deltuva VP, Tamasauskas A, et al. Brain MRI morphometric analysis in Parkinson's disease patients with sleep disturbances. BMC Neurol 2018;18(1):88. PMID 29925331
- 84
- Rahayel S, Gaubert M, Postuma RB, et al. Brain atrophy in Parkinson’s disease with polysomnography-confirmed REM sleep behavior disorder. Sleep 2019;42(6):zsz062. PMID 30854555
- 85
- Raschellà F, Scafa S, Puiatti A, Martin Moraud E, Ratti PL. Actigraphy enables home screening of REM behavior disorder in Parkinson’s disease. Ann Neurol 2023;93(2):317-29. PMID 36193943
- 86
- Reynolds GO, Otto MW, Ellis TD, Cronin-Golomb A. The therapeutic potential of exercise to improve mood, cognition, and sleep in Parkinson's disease. Mov Disord 2016;31(1):23-38. PMID 26715466
- 87
- Ricciardi L, Sorbera C, Barbuto M, Morgante F. Sleep disturbances are mainly improved by deep brain stimulation of the subthalamic nucleus. Mov Disord 2019;34(1):154-5. PMID 30653735
- 88
- Rijsman RM, Schoolderman LF, Rundervoort RS, Louter M. Restless legs syndrome in Parkinson's disease. Parkinsonism Relat Disord 2014;20 Suppl 1:S5-9. PMID 24262188
- 89
- Rios Romenets S, Creti L, Fichten C, et al. Doxpein and cognitive behavioral therapy for insomnia in patients with Parkinson’s disease -- a randomized study. Parkinsonism Relat Disord 2013;19(7):670-5. PMID 23561946
- 90
- Rodrigues TM, Castro Caldas A, Ferreira JJ. Pharmacological interventions for daytime sleepiness and sleep disorders in Parkinson's disease: systematic review and meta-analysis. Parkinsonism Relat Disord 2016;27:25-34. PMID 27010071
- 91
- Rukavina K, Batzu L, Leta V, Chaudhuri KR. New approaches to treatments for sleep, pain and autonomic failure in Parkinson's disease – Pharmacological therapies. Neuropharmacology 2022;208:108959.** PMID 35051446
- 92
- Rutten S, Vriend C, Smit JH, et al. Bright light therapy for depression in Parkinson disease: a randomized controlled trial. Neurology 2019;92(11):e1145-56. PMID 30770426
- 93
- Rutten S, Vriend C, van der Werf YD, Berendse HW, Weintraub D, van den Heuvel OA. The bidirectional longitudinal relationship between insomnia, depression and anxiety in patients with early-stage, medication-naïve Parkinson’s disease. Parkinsonism Relat Disord 2017:39:31-6. PMID 28365203
- 94
- Sauerbier A, Jenner P, Todorova A, Chaudhuri KR. Nonmotor subtypes and Parkinson’s disease. Parkinsonism Relat Disord 2016;22 Suppl 1:S41-6. PMID 26459660
- 95
- Scanga A, Lafontaine AL, Kaminska M. An overview of the effects of levodopa and dopaminergic agonists on sleep disorders in Parkinson's disease. J Clin Sleep Med 2023;19(6):1133-44. PMID 36716191
- 96
- Schettino C, Dato C, Capaldo G, Sampaolo S, Di Iorio G, Melone MA. Rasagiline for sleep disorders in patients with Parkinson’s disease: a prospective observational study. Neuropsychiatr Dis Treat 2016;12:2497-502. PMID 27729794
- 97
- Schreiner SJ, Imbach LL, Werth E, et al. Slow-wave sleep and motor progression in Parkinson disease. Ann Neurol 2019;85(5):765-70. PMID 30887557
- 98
- Schreiner SJ, Werth E, Ballmer L, et al. Sleep spindle and slow wave activity in Parkinson disease with excessive daytime sleepiness. Sleep 2023;46(4):zsac165. PMID 35877159
- 99
- Schrempf W, Fauser M, Wienecke M, et al. Rasagiline improves polysomnographic sleep parameters in patients with Parkinson's disease: a double-blind, baseline-controlled trial. Eur J Neurol 2018;25(4):672-9. PMID 29322594
- 100
- Shen Y, Shen Y, Dong ZF, Pan PL, Shi HC, Liu CF. Obstructive sleep apnea in Parkinson's disease: a study in 239 Chinese patients. Sleep Med 2020;67:237-43. PMID 31981970
- 101
- Sherif E, Valko PO, Overeem S, Baumann CR. Sleep benefit in Parkinson’s disease is associated with short sleep times. Parkinsonism Relat Disord 2014;20(1):116-8. PMID 24084381
- 102
- Simuni T, Caspell-Garcia C, Coffey C, et al. Correlates of excessive daytime sleepiness in de novo Parkinson's disease: a case control study. Mov Disord 2015;30(10):1371-81. PMID 26095202
- 103
- Sixel-Doring F, Trautmann E, Mollenhauer B, Trenkwalder C. Age, drugs, or disease: what alters the macrostructure of sleep in Parkinson’s disease. Sleep Med 2012;13(9):1178-83.** PMID 22841842
- 104
- Sixel-Döring F, Zimmermann J, Wegener A, Mollenhauer B, Trenkwalder C. The evolution of REM sleep behavior disorder in early Parkinson disease. Sleep 2016;39(9):1737-42. PMID 27306265
- 105
- Smilowska K, van Wamelen DJ, Schoutens AMC, Meinders MJ, Bloem BR. Blue light therapy glasses in Parkinson’s disease: patients’ experience. Parkinsons Dis 2019;2019:1906271. PMID 6604290
- 106
- Stauder M, Klerman EB, Wang W, Erickson H, Videnovic A. Relationships of self-reported and objective measures of sleep, sleepiness, and sleep quality in Parkinson's disease. Parkinsonism Relat Disord 2022;101:57-61. PMID 35797857
- 107
- Sun AP, Liu N, Zhang YS, Zhao HY, Liu XL. The relationship between obstructive sleep apnea and Parkinson's disease: a systematic review and meta-analysis. Neurol Sci 2020;41(5):1153-62. PMID 31897944
- 108
- Tall P, Qamar MA, Rosenzweig I, et al. The Park Sleep subtype in Parkinson's disease: from concept to clinic. Expert Opin Pharmacother 2023;24(15):1725-36. PMID 37561080
- 109
- Thannickal TC, Lai YY, Siegel JM. Hypocretin (orexin) cell loss in Parkinson’s disease. Brain 2007;130(Pt 6):1586-95. PMID 17491094
- 110
- Tholfsen LK, Larsen JP, Schulz J, Tysnes OB, Gjerstad MD. Development of excessive daytime sleepiness in early Parkinson disease. Neurology 2015;85(2):162-8. PMID 26085603
- 111
- Trampus M, Ongini E. The D-sub-1 receptor antagonist SCH 23390 enhances REM sleep in the rat. Neuropharmacology 1990;10:889-93. PMID 2147740
- 112
- Trotti LM, Bliwise DL. Treatment of the sleep disorders associated with Parkinson's disease. Neurotherapeutics 2014;11(1):68-77. PMID 24272458
- 113
- van Gilst MM, Louter M, Baumann CR, Bloem BR, Overeem S. Sleep benefit in Parkinson’s disease: time to revive an enigma? J Parkinsons Dis 2012;2(2):167-70. PMID 23939441
- 114
- Vaughan CP, Juncos JL, Trotti LM, Johnson TM 2nd, Bliwise DL. Nocturia and overnight polysomnography in Parkinson disease. Neurourol Urodyn 2013;32(8):1080-5. PMID 23359220
- 115
- Videnovic A, Klerman EB, Wang W, Marconi A, Kuhta T, Zee PC. Timed light therapy for sleep and daytime sleepiness associated with Parkinson disease: a randomized clinical trial. JAMA Neurol 2017;74(4):411-8. PMID 28241159
- 116
- Videnovic A, Noble C, Reid KJ, et al. Circadian melatonin rhythm and excessive daytime sleepiness in Parkinson disease. JAMA Neurol 2014;71(4):463-9. PMID 24566763
- 117
- Wang C, Chen F, Li Y, Liu J. Possible predictors of phenoconversion in isolated REM sleep behaviour disorder: a systematic review and meta-analysis. J Neurol Neurosurg Psychiatry 2022;93(4):395-403.** PMID 34937751
- 118
- Wen MC, Chan LL, Tan LCS, Tan EK. Mood and neural correlates of excessive daytime sleepiness in Parkinson’s disease. Acta Neurol Scand 2017;136(2):84-96. PMID 28670700
- 119
- Wilson H, Giordano B, Turkheimer FE, Chaudhuri KR, Politis M. Serotonergic dysregulation is linked to sleep problems in Parkinson's disease. Neuroimage Clin 2018;18:630-7. PMID 29845011
- 120
- Wong JC, Li Y, Schwarzschild MA, Ascherio A, Gao X. Restless legs syndrome: an early clinical feature of Parkinson disease in men. Sleep 2014;37(2):369-72. PMID 24497665
- 121
- Xu Z, Anderson KN, Pavese N. Longitudinal studies of sleep disturbances in Parkinson's Disease. Curr Neurol Neurosci Rep 2022;22(10):635-55. PMID 36018498
- 122
- Xu Z, Anderson KN, Saffari SE, et al. Progression of sleep disturbances in Parkinson's disease: a 5-year longitudinal study. J Neurol 2021;268(1):312-20. PMID 32804280
- 123
- Yang X, Liu B, Shen H, et al. Prevalence of restless legs syndrome in Parkinson's disease: a systematic review and meta-analysis of observational studies. Sleep Med 2018;43:40-6. PMID 29482811
- 124
- Ylikoski A, Martikainen K, Partinen M. Parasomnias and isolated sleep symptoms in Parkinson’s disease: a questionnaire study on 661 patients. J Neurol Sci 2014;346(1-2):204-8. PMID 25201715
- 125
- You S, Jeon SM, Do SY, Cho YW. Restless legs syndrome in Parkinson’s disease patients: clinical features including motor and nonmotor symptoms. J Clin Neurol Seoul Korea 2019;15(3):321-7. PMID 31286703
- 126
- Zhang W, Chen XY, Su SW, et al. Exogenous melatonin for sleep disorders in neurodegenerative diseases: a meta-analysis of randomized clinical trials. Neurol Sci 2016;37(1):57-65. PMID 26255301
- 127
- Zhao A, Li Y, Niu M, et al. SNCA hypomethylation in rapid eye movement sleep behavior disorder is a potential biomarker for Parkinson’s disease. J Parkinsons Dis 2020;10(3):1023-31. PMID 32444558
- 128
- Zhong G, Bolitho S, Grunstein R, Naismith SL, Lewis SJ. The relationship between thermoregulation and REM sleep behaviour disorder in Parkinson’s disease. PLoS One 2013;8(8):e72661. PMID 23991135
- 129
- Zhu K, van Hilten JJ, Marinus J. Course and risk factors for excessive daytime sleepiness in Parkinson's disease. Parkinsonism Relat Disord 2016;24:34-40. PMID 26846609
Contributors
All contributors' financial relationships have been reviewed and mitigated to ensure that this and every other article is free from commercial bias.
Author
-
Federica Provini MD
Dr. Provini of the University of Bologna and IRCCS Institute of Neurological Sciences of Bologna received speakers' fees from Idorsia, Italfarmaco, and NeoPharmed Gentili Spa.
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Editor
-
Antonio Culebras MD FAAN FAHA FAASM
Dr. Culebras of SUNY Upstate Medical University at Syracuse has no relevant financial relationships to disclose.
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Former Authors
- Giuseppe Loddo MD
- Michael Aldrich MD (original author), Robert L Rodnitzky MD, Ramadevi RG Gourineni MD, Sabra M Abbott MD PhD, and Stefano Zanigni MD PhD
Patient Profile
- Age range of presentation
-
- Typical:after 61 years
- Atypical:21-40 years
- Sex preponderance
-
- male=female
- Heredity
-
- none
- Population groups selectively affected
-
- none selectively affected
- Occupation groups selectively affected
-
- none selectively affected
ICD & OMIM codes
- ICD-9
-
- Other specified extrapyramidal and movement disorders – restless legs syndrome: 333.94
- ICD-10
-
- Other specified extrapyramidal and movement disorders – restless legs syndrome: G25.8
- Parkinson disease: G20
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