Neuro-Oncology
Anti-LGI1 encephalitis
Oct. 03, 2024
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Toll Free (U.S. + Canada): 800-452-2400
US Number: +1-619-640-4660
Support: service@medlink.com
Editor: editor@medlink.com
ISSN: 2831-9125
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The mental status examination is a core component of a comprehensive physical, neurologic, or neuropsychological examination that evaluates a patient’s cognitive (eg, attention, visuospatial, language, memory, and executive functioning), affective, and behavioral functioning. The mental status examination is a uniformly brief (approximately 5 to 15 minutes), in-person, paper-and-pencil measure administered individually by a physician or clinician (eg, neuropsychologist), directly to the patient, or indirectly to an informant. The mental status examination should include the use of standardized screening instruments to enhance objectivity, diagnostic reliability, and validity. Traditionally developed for and used with adults, the mental status examination has been used with child and adolescent populations. Recent considerations and applications include cultural adaptations, linguistic translations, use with minoritized populations, and tele-administrations.
• Mental status examinations, also known as cognitive screening measures, are standardized tools used by medical and behavioral health professionals, typically neurologists and neuropsychologists, that involve administering a set of individual subtests belonging to one or more composite cognitive, behavioral, or affective domains. Cognitive domains reflect different regions of cortical function and, as such, provide insights regarding the integrity of the respective neuroanatomical correlates. | |
• A number of psychometrically sound cognitive screening tools include the Mini-Mental Status Examination (MMSE), which is one of the most widely used screening tools in the United States; the Montreal Cognitive Assessment (MoCA), which seems to be more sensitive in mild cognitive impairment; the Addenbrooke’s Cognitive Assessment III (ACD-III), which identifies everyday functional impairments; and the Saint Louis University Mental Status (SLUMS), which is designed for a United States veteran population. | |
• Mental status examinations can be administered at the bedside as part of an emergency room or inpatient evaluation and during outpatient evaluations. Several measures have been found to have adequate-to-high sensitivity and specificity for predicting or tracking neurologic disease and recovery. | |
• Spoken and sign language adaptations and translations exist for several mental status examinations, including the Mini-Mental Status Examination and the Montreal Cognitive Assessment. | |
• Mental status examinations have been researched as part of distance evaluations since the 1980s and are increasingly used as part of teleassessments for individuals across the lifespan, especially since the COVID-19 pandemic. |
Mental status examinations span a wide range of sophistication, from patient observation during history-taking and physical examination to extensive neurologic and neuropsychological testing in standardized settings. Bedside mental status examination tools have been developed to combine ease of administration with standardized scoring. Klein and Mayer-Gross created one of the first measures (48). Other tests include Kahn’s Mental Status Questionnaire (44), Short Portable Mental Status Questionnaire (77), Mattis Dementia Rating Scale and the second edition (DRS and DRS-2, respectively) (57; 43), Cognitive Capacity Screening Examination (40), Mini-Mental Status Examination (MMSE) (29), Modified Mini-Mental State Examination (3MS) (93), Montreal Cognitive Assessment (MoCA) (68), and Addenbrooke’s Cognitive Assessment III (ACE-III) (37).
The best-known of these tools is the MMSE, which was primarily developed to screen for organic behavioral signs and facilitate the diagnosis of general organic mental syndromes (eg, dementia) or specific organic mental disorders (eg, Alzheimer disease). As efficient treatment of these conditions has become available, the MMSE and other mental status examinations have been used to monitor outcomes and recovery of function and evaluate treatment effects. For example, the Montreal Cognitive Assessment scale seems to be more sensitive in the early stages of Alzheimer disease and mild cognitive impairment.
Disease-specific tools that are more sensitive and specific also have been developed. They are generally a little more complicated to administer but are simpler than full neurologic and neuropsychological examinations (eg, DRS, DRS-2, and The Alzheimer's Disease Assessment Scale-Cognitive Subscale [ADAS-COG]). The ADAS-COG is a widely used cognitive scale in clinical trials and is considered one of the gold standards for evaluating treatment in Alzheimer disease and mild cognitive impairment (79).
Standardized cognitive screening measures involve the administration of individual subtests belonging to one or more composite cognitive, behavioral, or affective domains. Cognitive domains reflect different regions of cortical function and, as such, provide insights regarding the integrity of the respective neuroanatomical correlates. Some aspects of cognitive functioning, such as the patient’s awareness of symptoms, are generally not covered by these measures directly but are assessed informally during the clinical interview or by gathering collateral data from individuals familiar with the patient’s functioning (99). Alterations in consciousness (eg, delirium or coma) preclude using most mental status screening measures designed to assess higher-level cognitive and behavioral functions (see Contraindications). However, physicians should be aware that standardized measures have been developed to assess and monitor alterations in consciousness, such as delirium (eg, the 3D Confusion Assessment Method, 3D-CAM) (54) or coma (eg, the Coma Recovery Scale-Revised, CRS-R) (31).
All mental status examinations should be interpreted within the context of the patient’s background and lived experience (eg, age, education, racial and ethnic identities, culture, linguistic status, socioeconomic status, and acculturation) to reduce the potential for pathologizing pre-morbid cognitive weaknesses. Care should also be taken to identify when using standardized measures may not be appropriate (eg, individuals with limited educational experiences or for whom standardized measures are not available in their native language).
The following are explanations of major domains of functioning typically tested via a mental status examination.
Orientation refers to a person’s awareness of themself, their situation, and their surroundings. In the context of cognitive screening measures, orientation is sometimes treated as a distinct domain or is otherwise included within the domain of memory or, occasionally, attention.
Orientation is typically assessed by asking the patient a series of questions about autobiographical information (eg, their name, age, and date and place of birth), time (eg, the current month, year, date, day of the week, and time of day), place (eg, the type and name of the facility and the town, state, and country in which that facility is located), and situation (eg, asking the patient to provide an account of why they are being evaluated and the event or events that led to the evaluation).
Attention encompasses a range of skills related to a person’s ability to orient to and process external (environmental) and internal stimuli and information. The ability to meaningfully select and maintain focus on a specific stimulus is integral to attention and stands in contrast to the concept of alertness, which is a more basic arousal process that allows the awake person to respond to any stimulus in the environment. Aspects of attention measured by the mental status examination may include basic attentional capacity, sustained attention, and alternating attention.
Basic attention. Basic attention is the patient’s capacity to hold simple information that must be rehearsed to not be lost (ie, decay of memory trace). Basic attention is most commonly assessed with measures of simple digit span, where a patient must repeat back strings of digits of increasing length until they reach their capacity to do so accurately.
Sustained attention. Sustained attention, also called vigilance or concentration, refers to the patient’s ability to maintain attention on a specific stimulus for a period of time. This may be assessed informally in the evaluation, such as by observing the patient’s ability to maintain engagement in a conversation or activity without intentionally or unintentionally shifting their attention to extraneous external or internal stimuli. Formal measures of sustained attention often involve exposing the patient to a series of numbers or digits and having them produce a response only to specific items within that series. For example, a patient may be asked to listen to a series of numbers and to tap their hand when and only when they hear a specific number.
Alternating attention. Alternating attention refers to the patient’s ability to deliberately shift their attention back and forth between two tasks or sets of stimuli. Alternating attention is sometimes subsumed within the domain of executive functioning rather than attention. A common task assessing alternating attention involves asking the patient to switch between listening to or visually connecting numbers and letters in order.
Language must be evaluated early in the course of the examination, as disturbances to language, such as aphasia, may render the patient unable to perform other cognitive tasks (ie, through inability or difficulties to understand task instructions accurately or to produce the language necessary to meet the task demands sufficiently). Language assessment should examine the following features to elucidate the presence and type of aphasia or another language disturbance.
Expressive language. The physician or clinician should attend carefully to the patient’s spontaneous speech production and ask open-ended questions, attending to articulation, lexicon, semantics, syntax, prosody, and related errors (eg, word-finding errors or phonemic or semantic paraphasic errors). For culturally Deaf individuals using American Sign Language, similar aspects of articulation (eg, nonmanual markers) and expressive sign language should be evaluated through an American Sign Language-fluent clinician or interpreter. Expressive language may also be assessed by having the patient describe a picture or an object.
Comprehension. The patient’s ability to understand both simple and complex instructions should be carefully evaluated. Basic responding is assessed by asking the patient a series of Yes or No questions with unambiguous answers that should be known to the patient. The patient’s ability to understand simple commands of increasing length and complexity also should be tested. Examples of comprehension measures include asking the patient to perform a series of tasks involving an object (eg, manipulating a piece of paper) or following one-, two-, or three-step instructions. Additionally, comprehension should be informally assessed throughout the evaluation by attending to the appropriateness and consistency of the patient’s responses to questions and their ability to correctly participate in other aspects of the examination (eg, to stand and walk in a straight line when asked to do so).
Repetition. The patient’s ability to repeat single words and sentences of varying complexity should be evaluated, with careful attention to grammar, omissions, additions, perseverations, and naming errors. Some structured screening measures include a standardized set of single words or sentences that the patient is asked to repeat.
Naming. The ability to name objects is a basic element of language that may be compromised in various neurologic conditions. Naming can be tested informally by pointing to a range of objects in the examination room belonging to a variety of categories and asking the patient to name them. Patients also may be shown photographs or drawings of various objects and asked to name them. Noticeable pauses for word-finding or production of semantic (ie, category) or phonemic (ie, sound) errors during naming tasks, even if the patient can produce the target word, should raise concern for naming difficulties. Several mental status examinations provide semantic or phonemic cues when patients experience difficulty freely naming an object or picture.
Reading. Reading is typically evaluated by having the patient read simple words and sentences printed on a page. For these items, examiner attention should be paid to the patient’s reading fluency, syntax and articulation errors, and omissions and additions. However, it is important to consider which language (eg, L1: native language; L2: non-native, heritage, or acquired language) should be used to evaluate this domain depending on the language and educational experiences of the patient and their functioning in home, educational, and work settings.
Writing. Writing ability can be assessed by having the patient write words or compose and write sentences based on a stimulus cue, as well as writing words and sentences from dictation. Their written production should be evaluated for legibility, spelling errors, syntax, and semantic value (ie, Did their writing convey meaningful information?). Similar to reading, the language and educational backgrounds of the patient should be considered when selecting a formal mental status examination and basing conclusions on informal writing samples.
Visuospatial functions refer to the patient’s ability to perceive, locate, process, analyze, and manipulate visual information. In the mental status examination, visuospatial skills can be divided into two broad categories (ie, visual perception and visual constructional abilities).
Visual perception. Visual perception can be assessed by observing the patient’s interactions with their environment (eg, their ability to navigate the examination room). Other means of assessment include having the patient count dots or letters scattered across a page, identify fragmented or partially obscured objects, or match two images or objects from a field of several choices. Attention should also be paid to errors on other cognitive screening items, such as misperceptions of pictures in confrontation naming tasks (eg, mistaking the drawing of a musical instrument for a staircase).
Visual construction. Visual construction is typically assessed through (1) reproduction of drawings, such as making copies of visually presented geometric shapes of increasing complexity, or (2) drawing to command, in which the patient is requested to draw simple everyday objects.
Memory on the mental status examination typically refers to a three-part process comprised of (1) encoding, (2) retaining, and (3) retrieving information. Memory is complex and conceptualized via different theoretical models or processes, such as type of knowledge (eg, facts versus procedural skills) or modality (ie, verbal versus visual). Furthermore, the three aspects of memory typically assessed in the mental status examination are based on the period between stimulus presentation and memory retrieval: (1) immediate, (2) recent, and (3) remote.
Immediate memory. Sometimes referred to as short-term memory, immediate memory refers to recalling an information trace after an interval of a few seconds. Although immediate memory is typically evaluated within the domain of attention, such as by having the patient repeat digits or a few words immediately after exposure, it also requires a degree of memory functioning. However, this information typically decays quickly if the patient is not asked to recall it again or if they are not instructed to remember it later during the mental status examination.
Recent memory. Recent memory refers to the ability to retain new material and to retrieve that material after relatively brief intervals (ie, minutes or hours). Recent memory may be tested through orientation questions, asking the patient to recall information previously presented in the examination (eg, a list of words or a short story), and by having the patient provide details of recent personal or world events with corroboration from a collateral source. When information cannot be remembered, it is typically considered a function of forgetting rather than a decay of the information (memory) trace.
Remote memory. Remote memory refers to older memories (eg, events occurring weeks, months, years, or decades earlier). Remote memories, unlike recent memories, are highly stable and generally resistant to neurologic damage and disease. Remote memory is often evaluated as part of orientation (ie, asking the patient for their name, the names of their parents, and their date and place of birth). The patient may be asked questions of semantic knowledge generally known to the public (eg, the name of particular past presidents), but care should be taken to determine that these questions are appropriate to the patient’s level of education and acculturation. Like recall, loss of such information due to an underlying change in neurologic mechanisms is considered forgetting.
Recall versus recognition. The above typically represent the encoding and storage of information. Evaluation of the patient’s ability to remember information presented during the mental status examinations or from their knowledge base or life experience is typically through either free recall (eg, asked to produce information with a general or minimal cue), cued recall (eg, asked to produce the information with a specific cue, such as a word, categorical reference, or picture), or recognition (selection of a target piece of information from foils or distractors via a Yes/No or multiple-choice format question).
Executive functions are a heterogeneous collection of skills broadly associated with frontal lobe functioning and are necessary for the patient to independently engage in purposeful behavior. Executive functions have considerable overlap with other cognitive domains. For example, mental manipulation, alternating attention, and vigilance, although described earlier within the domain of attention, are often conceptualized as executive functions. Similarly, measures of visual construction provide valuable information about the patient’s ability to plan and execute a task successfully. The following also should be briefly screened as part of the mental status examination.
Sequencing and shifting. Patients are asked to identify or maintain sequences of information, such as certain verbal cues, letters, or number sequences. Additionally, they may be asked to hold certain types of information and shift their responses according to specific instructions.
Working memory. Working memory is the patient’s ability to mentally manipulate information held in temporary attentional storage, which either decays without further mental effort or is transferred to long-term memory storage (ie, remote memory). Working memory is most often assessed by having the patient perform digit reversal or sequencing tasks, spell words backward, or perform simple mental arithmetic.
Category formation and abstract reasoning. The patient may be asked to identify similarities in various groups of objects, and the practitioner should assess whether or not they can provide a high-level response (ie, identify an overall category, class, or function), a concrete response (ie, identify shared surface characteristics), or no response. For example, if the patient were asked how a dog and a cat were similar, they could identify both as animals or mammals (an abstract response), state that both have fur or four legs (concrete responses), or state that they are different or not the same (inability to identify a relationship between them).
Behavior and personality. These areas should be evaluated through careful observation of patient behavior and feedback from collateral sources who know the patient well. The practitioner should be attentive to signs of atypical behaviors or personality characteristics given the background and lived experiences of the patient, as well as information provided by collateral sources. Additionally, the clinician should look for atypical or unusual distractibility, disinhibition, impulsivity, mood lability, indifference, abulia, and reduced or absent initiation.
Affect and mood. Affect refers to the patient’s current emotional state as expressed through nonverbal means, such as facial expression, posture, and body movement. Affect is assessed through careful observation of the patient throughout the evaluation. Mood refers to the patient’s current overarching state of emotional feeling and is typically stable and pervasive across settings. Mood should be assessed through patient self-report, administration of standardized measures that screen for depression (eg, the Patient Health Questionnaire – 7; PHQ-7) and anxiety (eg, the General Anxiety Disorder – 7; GAD-7), or report from collateral sources.
The most commonly used screening tools in the United States include the Addenbrooke's Cognitive Examination-III (37), Mini-Mental State Examination (29), Montreal Cognitive Assessment (68), Saint Louis University Mental Status (66), and MiniCog (04), among others (70; 01; 61; 46).
Mini-Mental State Examination (MMSE). The MMSE is the best-known mental status examination test battery (29). Surveys have indicated that the MMSE is the most commonly used screener in assessing neuropsychiatric aspects of older adults (87; 39; 42) and the most studied in research (95).
Traditionally, the MMSE has been administered at the bedside or in the office. It requires that the patient has access to a hard surface when writing and drawing. The MMSE comprises 11 questions assessing orientation to time and place, attention or calculation, immediate and short-term recall, language (naming, repetition, comprehension, reading, and writing), and visuospatial abilities (drawing or construction). One noted disadvantage is that it lacks any evaluation of executive functioning. It also has been copyrighted by Psychological Assessment Resources and, thus, is no longer in the public domain.
The score is a weighted sum of the items. The maximum score is 30 points. Some disagreement exists concerning what constitutes an abnormal score. Most authors suggest that patients scoring below 24 are cognitively impaired (69; 18). The MMSE is not typically used to evaluate early cognitive impairment, especially at the cutoff score of 24 (84). Some accept lower scores as normal, and a few find that 18 is the limit below which definite cognitive impairment is present (08). However, Kvitting and others recommend a cut-off score of 26 for those 85 years of age and older (50), and Chun and colleagues suggest 26 or less for mild cognitive impairment (17). One of the problems with the MMSE is that it only provides a single score, which is used to identify the presence and degree of brain disease; thus, it is only a gross estimate of the patient’s global cognitive functioning (90). It often fails to detect focal brain injury and resulting specific cognitive deficits (28). Right-hemisphere lesions are especially overlooked by the MMSE.
It should be noted that age and education strongly influence test scores, which makes it difficult to interpret a low score obtained by an elderly patient with modest intelligence or limited education (07); typically, at least an eighth-grade education is needed. The MMSE is also less effective when administered to individuals with limited literacy (74). It is possible for intelligent, well-educated persons who are cognitively impaired to perform within the normal range because their premorbid performance was so high that a test of global functioning does not pick up a modest reduction.
The Montreal Cognitive Assessment (MoCA). The Montreal Cognitive Assessment is a bedside test considered more sensitive to mild cognitive impairment than the MMSE (68). This test also has a maximum score of 30 based on visuospatial performance, naming, memory, attention, language, abstraction, and orientation. It is generally thought to reflect right hemisphere function and executive functioning more than the MMSE; there is no measure of processing speed. The Montreal Cognitive Assessment is available from https://mocacognition.com in both paper and mobile tablet versions, and the website states that the test is available in almost 100 languages in paper and five languages with the app version. Since September 2019, a 1-hour training and certification has been mandatory, although certain groups, such as trainees and neuropsychologists, are exempt. The website also refers to many validation studies of the Montreal Cognitive Assessment.
The original cut-off score for the Montreal Cognitive Assessment was 26 (68), with scores of 25 or lower indicating mild cognitive impairment. To lessen misclassification, Ratcliffe and colleagues suggest a cutoff of 25 or lower for White versus 22 or lower for Black-identified individuals, despite both groups being highly educated (82). However, additional research is required to evaluate this recommendation. Another study of non-Hispanic White and Black Americans showed that the Montreal Cognitive Assessment, supplemented by a functional measure, improved diagnostic accuracy between the cognitively unimpaired, mild cognitive impairment, and dementia (33). Using a double threshold has been suggested to utilize the Montreal Cognitive Assessment to triage patients needing further neuropsychological evaluation (20). In this two-stage process, Montreal Cognitive Assessment scores under 21 indicate those who should be assessed further, whereas those scoring 26 or higher could be discharged, and those who score 21 to 26 would be considered at risk for dementia.
Addenbrooke's Cognitive Examination (ACE-III). The ACE-III takes longer to administer than the MMSE or the Montreal Cognitive Assessment (37). The measure covers areas of memory, language, word fluency, attention, and visuospatial skills. The highest score is 100, with higher scores indicating better memory and general cognitive function. The ACE-III is the second update from the original ACE (56), which incorporated the MMSE with additional tests of executive functioning; it was developed to differentiate Alzheimer disease and frontotemporal dementia. It is available for free at the University of Sydney at https://www.sydney.edu.au/brain-mind/resources-for-clinicians/dementia-test.html.
The ACE-III has good sensitivity and specificity in assessing cognitive deficits in people with Alzheimer disease and frontotemporal dementia (37). It seems to be more sensitive to impairment of everyday activity than the MMSE or Montreal Cognitive Assessment (32). A systematic review of 28 screening tools used on older adults by primary care providers found that the Montreal Cognitive Assessment was the most common and preferable tool for screening mild cognitive impairment, given its sensitivity, whereas the original Addenbrooke's Cognitive Examination (ACE) was the preferable tool for screening dementia (01).
Saint Louis University Mental Status (SLUMS). The Saint Louis University Mental Status examination was found to be a good alternative to the Montreal Cognitive Assessment, as it is also out of 30 points, has tasks of executive functioning, can be administered in a variety of languages, and accounts for education (66; 88; 72). It incorporates tasks of orientation, calculation, semantic verbal fluency, word and story recall, reverse digit span, clock drawing, and visuospatial function. It is available free from Saint Louis University at https://www.slu.edu/medicine/internal-medicine/geriatric-medicine/aging-successfully/-pdf/mental-status-exam.pdf. When compared to the MMSE for detecting mild neurocognitive disorder, the Saint Louis University Mental Status examination proved better (92).
Mini-Cog. The Mini-Cog is a 3-minute cognitive screen made up of clock drawing and a three-word recall and is considered better than the MMSE for non-English speakers (04; 05). It has higher sensitivity for dementia than for mild cognitive impairment. Comparing the MMSE to the Mini-Cog, Malini found the Mini-Cog effective as a screening tool in older adults but less so in those with lower education (52). Tuch and colleagues, in a rapid review, also recommended the Mini-Cog over both the MMSE and the Montreal Cognitive Assessment for assessing older adults with cancer (96). It is available for free from the Alzheimer’s Association at https://www.alz.org/media/documents/mini-cog.pdf.
Other Screeners. There has been an increase in the number of systematic reviews of cognitive screening instruments and in the development of new testing instruments. Following are examples of additional screeners.
Clock-Drawing Test (CDT). The clock-drawing test is easy to administer and score, although it does not assess memory, per se (36; 85). It has been shown to be better for identifying dementia than mild cognitive impairment. In a scoping review, Chun and colleagues found the Montreal Cognitive Assessment, the MMSE (with a cut-off score of 26), and the clock-drawing test to be the most used for diagnosing mild cognitive impairment (17). Brain Check is a tool that includes a formula utilizing the clock-drawing test, informant information, and a decision tree to detect incipient cognitive decline (26).
Oxford Cognitive Screen (OCS). When focusing on specific cognitive domains in stroke, such as visual inattention and visual field cuts, Demeyere and colleagues found that the Oxford Cognitive Screen was overall more sensitive than the Montreal Cognitive Assessment and detected important cognitive deficits after stroke not assessed in the Montreal Cognitive Assessment (24). The Oxford Cognitive Screen also has been shown to be more sensitive to stroke-specific impairments than the MMSE (53). However, in a critical review, Murphy and colleagues found the Oxford Cognitive Screen insensitive to memory problems and favoring the cognitive sequelae from left-hemisphere strokes (67).
Severe Mini-Mental State Examination. For patients with predominantly severe cognitive defects, other modifications have been made, for instance, the Severe Mini-Mental State Examination, which has been found to be useful for assessing severely impaired patients with Alzheimer disease (35). Despite the problems and limitations of the MMSE, this test remains a robust and easily administered test, suitable for first-line clinical practice.
The Hong Kong Brief Cognitive Test (HKBC). The Hong Kong Brief Cognitive Test was developed to provide a simple test for subjects with low educational levels (16). It has been validated in Hong Kong on 359 subjects with neurocognitive disorder or normal controls. There was a high overlap between the HKBC and MMSE, as well as the Montreal Cognitive Assessment. The validity at low educational levels is still under investigation. The HKBC also was found to be more sensitive and specific than the MMSE for detecting amnestic mild cognitive impairment and Alzheimer disease in a Chinese population (91).
Rowland Universal Dementia Assessment (RUDAS). The Rowland Universal Dementia Assessment is a six-item test designed as a multi-cultural screener and validated in Australia (89).
Global Examination of Mental State (GEMS). The Global Examination of Mental State is an 11-item test, with tasks weighted evenly, up to 100 points. It was developed in Italy and has parallel versions. The Global Examination of Mental State does not address any specific diagnosis or disorder (64). It is available free at https://osf.io/4t5a8.
Other screeners. Other screeners include the Short Portable Mental Status Questionnaire (14), MyCog ap (101), and Test Your Memory (97). The General Practitioner Assessment of Cognition (GPCOG) is different, as it is fast to administer with only 10 items and includes an informant interview; it is meant to be administered by general practitioners. The GPCOG was found to be similar to, but faster than, the MMSE (12).
Thus, many validated mental status examination tools exist. They vary in ease and speed of administration, sensitivity and specificity on disease progression and diagnostics, relative focus, and various cognitive domains. It is worth noting that the most extensive examinations tend to give the most detailed information. However, none of the screeners are valid for differential diagnosis, and practitioners should not rely too heavily on any one screener.
Physical examination by neurologists and psychiatrists almost always involves some degree of mental status evaluation. As previously noted, the type and extent of evaluation depends on the issues under consideration and the state of the patient. The multitude of components in a mental status examination can be informative in probing for details for an underlying neurologic or neuropsychiatric condition. This form of bedside screening can also guide further examination that may include more comprehensive neuropsychological testing to detect more subtle deficits not fully captured by the mental status examination. Longitudinal use of mental status examination also may prove useful in the continued assessment and monitoring of neurodegenerative conditions, such as dementia or a neuromuscular condition (34; 59).
Overall, the mental status examination can be a useful aid for determining and differentiating conditions that are both neurologic and psychiatric, including delirium, dementia, depression, bipolar disorder, and schizophrenia (70). Mental status screening, in conjunction with additional assessment tools, can also be useful for diagnosing concussion. Follow-up administration of a mental status examination during the period after a concussion can be beneficial as there is a possibility of psychiatric conditions arising, most notably depression (58). Further, mental status screening is important for those who initially present vague behavioral complaints that are difficult to quantify clinically in the standard neurologic examination. Complaints such as memory problems, difficulties in concentration, declining interest in family or work, or various physical complaints without identified structural cerebral etiology should alert the clinician to the possibility of structural brain disease (90). Assessment for substance abuse and possible overdose also could benefit from the administration of a mental status examination to help identify cognitive functioning and aid in clinical decisions of possible increased risk of further complications (62).
Altered mental states may present challenges when considering mental status examination as part of a diagnostic evaluation. Altered mental states can be referred to as an “acute confusional state” or “confusion.” Typical characterization includes changes in awareness, cognition, attention, or consciousness. Delirium, typically referring to a specific condition that is acute and with fluctuating mental status, can also pose as challenging to assess with a mental status examination. Both altered mental status and delirium likely indicate the presence of another underlying medical condition that could be life-threatening, but with treatment, it could be reversible. Altered mental status is common among hospitalized adults, and nearly 10% of adults presenting to an emergency department exhibit altered mental status. A mental status examination may provide an important tool in the initial evaluation, but given the altered mental state present, physical examination, a review of known medical history, and neuroimaging become extremely valuable in differentiating diagnosis and determining the course of treatment. In some cases, the initial mental status examination may indicate a diagnosis of delirium, but as previously stated, additional, more comprehensive evaluations would be needed to determine the underlying conditions that may be causing the delirium and the course of treatment (98; 51).
The following conditions are the most common causes of confusional states: dementia, hypercapnia, hypoxia, ischemia, hypoglycemia, electrolyte derangement, ketoacidosis and other osmolarity abnormalities, renal failure, hepatic failure, trauma, tumors, hydrocephalus and other mechanical effects, hypothermia, drug or alcohol intoxication, endogenous metabolites, anesthesia, epilepsy, and infections. Mental status examinations may still yield useful information when assessing these types of conditions, but other factors should be considered. These include patient demographics, other medical conditions, poor sleep, psychiatric conditions, and medication side effects (34; 70). When the cause is immediately identifiable and treatable, the acute treatment should gain priority over elaborate mental status examinations; however, a few moments spent evaluating the mental state of a confused patient during the first contact may be well worth the effort.
Increasing numbers of studies examine changes to neurologic and neuropsychological functions among specific groups of disease processes using mental status examinations, as well as the use when providing clinical interventions and assisting in the process of determining outcomes. Because this literature is extensive, the following section provides a few examples describing the utility of the MMSE when identifying progressive illness. Several studies have looked at the relation between systemic disease and mental state using the MMSE. Often, the cognitive changes that are looked for are relatively small, and the result may be nonsignificant because the MMSE is not sufficiently sensitive. For example, Molander and coworkers found in a group of very old people (85 years of age and older) that those with low systolic blood pressure (120 mmHg) had lower scores on the MMSE than those with systolic blood pressure higher than 140 mmHg (63). In a group of patients who had experienced cardiac arrest, it was found that hypothermia was widely used to protect cerebral function (11). The MMSE score and several other variables were used to evaluate the overall outcome for these patients. No effect could be measured on the MMSE score (11).
The results of the MMSE for diagnostic work-up should generally be improved by comprehensive mental status examination and imaging, for instance, in patients suspected of having mild cognitive impairment for which the MMSE is often not sensitive enough (27). Multimodal methods have been developed for predicting the development of Alzheimer disease. A combination of PET images, MRI images, CSF measures, etc. can predict much later values of continuous clinical variables like the MMSE with high accuracy (103).
For example, the Alzheimer’s Disease Neuroimaging Initiative selected 523 individuals with various stages of preclinical or manifest Alzheimer disease for MRI scanning (25). They found an association between gray matter atrophy and MMSE score. Additionally, in a study of 51 patients with Alzheimer disease who received the acetylcholinesterase inhibitor donepezil hydrochloride, Shimizu and colleagues found that a decline in MMSE score was associated with a decrease in regional cerebral blood flow as evaluated by SPECT (86).
Age. Although cognitive screening is well established and widely used with adults, it may be practical for use with younger age groups. For example, cognitive screeners administered to children, adolescents, and young adults may assist with earlier evaluation of the potential impacts of developmental, psychiatric, or neurologic conditions on cognitive functioning. This domain is slowly emerging, and more research is needed on the feasibility and utility of measures sensitive to cognitive impairment in these earlier years (10). In the context of limited existing recommendations for cognitive screening tools with younger populations, recommendations have been proposed by Bryce and Allott, which include selecting measures that are brief, less than 30 minutes, appropriately normed with considerations of the diverse range of cognitive development, sensitive to detecting different cognitive concerns, and capable of being administered by appropriately trained health and allied professionals (09). A systematic review of cognitive screeners used with youths ages 12 to 25 years identified research evaluating 14 cognitive screeners applied to this population with ranging sensitivity and specificity to cognitive impairment (10). Their review reaffirmed the limited research and the need to further evaluate existing mental status examination measures for younger populations.
Turning to the group of adults sometimes termed the oldest-old, the number of validated measures becomes more limited. Normative data for some cognitive screening tools tend to include the 80- or 90-year range. For example, the normative data for the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) Update includes 89-year-old adults (81). Additionally, large-scale normative data are available for up to 105 years of age (ie, DRS-2), and various research-based normative samples also are being examined (eg, Montreal Cognitive Assessment) (60).
Disability and deafness. Screening and assessment of cognitive changes for patients with congenital or adventitious sensory experiences (eg, no light perception, low vision, and deafness) separate from the referral question typically present additional challenges. Several existing cognitive screening measures have been adapted as part of research studies for use with individuals who are blind or otherwise visually impaired (MoCA-Blind; MMSE-Blind) and for individuals with postlingual deafness or hearing loss (MoCA-H) (13; 21; 22; 47). Efforts have also been made to either adapt existing versions of mental status examinations for Deaf individuals who use American Sign Language (23) or develop a culturally and linguistically accessible and appropriate cognitive screening measure for the population (94). There remains, however, very limited research on these modifications and appropriate norms for measures used with these groups of individuals (41; 47; 83).
Intellectual disability. Another population to consider is individuals with intellectual disabilities. The aging process for individuals with intellectual disabilities is significantly variable and may depend on several factors, particularly the underlying condition. Although individuals with mild intellectual disability may follow a similar aging trajectory as the general adult population (76), individuals with Down syndrome may experience accelerated aging, placing them at higher risk for Alzheimer disease (02; 30). A review of screening measures for individuals with intellectual disability (73) identified the two most used measures being the Dementia Questionnaire for Learning Disabilities (102) and the Cambridge Cognitive Examination for Older Adults with Down Syndrome (CAMCOG-DS) (80). Caution was recommended in using measures validated with the general adult population due to limited sensitivity in detecting dementia (73).
Telemedicine and telepsychological administration. As early as the 1980s, researchers and clinicians have been increasingly interested in the feasibility and related psychometric properties of administering paper-based mental status examinations, among other neuropsychological measures, to individuals outside of the traditional inpatient and outpatient settings, especially assessment via telephones (65; 38). Some of the more commonly used measures, especially for research and clinical trials, have been the Telephone Interview for Cognitive Status (06), the modified Telephone Interview for Cognitive Status (100), and the Minnesota Cognitive Acuity Screen (49). Telephone-based versions of the MMSE (71) and Montreal Cognitive Assessment (75) also have been developed, which typically result in adapting or modifying items, especially those tapping visual-spatial and executive functions, that are challenging or impossible to administer via the phone. With the advent of information technology systems and devices during the past 20 years, approaches to distance cognitive screenings have incorporated video access from webcams and phone cameras.
When the COVID-19 pandemic resulted in restricted in-person evaluations, the research about and use of telemedicine and telepsychological assessment swelled and continues to be further developed, maintained, and evaluated at a staggering pace (03). This has been especially beneficial for populations who have difficulty coming to an outpatient office (eg, rural locations, disabled) or who require or prefer direct services from a provider without an interpreter (eg, Deaf individuals using American Sign Language, hearing individuals using spoken languages other than English) (78). A large number of these studies have focused on teleneuropsychological assessment of older healthy adults and individuals with neurologic disease processes and found few differences between in-person administration versus the use of tele-administration (15; 38; 19). However, these approaches are not necessarily accessible to those without access to such devices, who rely on weaker internet services, whose health or disability status does not allow them to navigate devices easily, or who have negative perceptions or experiences of technology. Another factor for consideration of the existing literature is that most of the studies conducted in the United States have included older White adults and either not clearly documented or directly addressed the tele-administration of measures for individuals with diverse lived experiences (55). This is slowly being addressed in the field (45).
Case 1: delirium. The patient was an 87-year-old White male with primary medical history of hypertension and diabetes Type II, with newly altered mental status and a urinary tract infection. A cognitive screening was requested to determine the patient’s mental and cognitive status. At the time of testing, the patient was alert and cooperative. His mood appeared cheerful, and his affect was congruent with his mood. The patient did not report pain.
The Montreal Cognitive Assessment was administered, resulting in a score of 11/30. He was not oriented to time, date, or place and had difficulty grasping instructions on non-recall tasks despite multiple repetitions of instructions. He only received one point on attention tasks and zero points on delayed recall. Given that the patient was not oriented and that he exhibited difficulty with comprehension and attention, delirium (possibly due to the urinary tract infection) was thought to be likely. This may have been superimposed on dementia, but his delirium would have to clear first for the evaluation of possible dementia. In fact, after the infection was resolved through antibiotics, his cognition returned to baseline.
Case 2: possible dementia; recommend further evaluation. The patient was a 91-year-old African American identified male with a primary medical history of hypertension, coronary artery disease, three stents, subtotal gastrectomy (resulting in a vitamin B12 deficiency), prostate cancer treated with CyberKnife, and parkinsonism. He was admitted after a fall in his driveway. A CT scan of his head was unremarkable. Given his complex history, the patient was referred for bedside cognitive screening to assess cognitive functioning by the attending neurologist because he was observed as impulsive and sometimes irrational.
The patient described his mood as “fine,” but he later reported feeling upset about his brother’s wife, who went to hospice a few days prior. He also reported feeling frustrated by the hospital staff. He talked about some unusual beliefs, such as noticing that his room was renovated overnight (he thought the sink was replaced). Although he denied any cognitive difficulties, he later admitted having noticed some changes recently (eg, forgetting things, feeling confused, and not being able to explain things); he felt these to be “age-related.”
His daughter reported that ever since the fall and his admission to the hospital, which is also when he first started taking medication for Parkinson disease, he had been confused, illogical, and physically weaker than she had ever seen. However, she also said that, for a few months before the fall, the family discovered that he had been hoarding money. Both the patient and his daughter mentioned that he had been unable to get enough sleep over the past couple of days. He denied having any pain. The patient completed two master’s degrees, worked as an electrical engineer, and was retired. He lived alone and was reportedly still driving prior to admission.
During the clinical interview, the patient was alert, cooperative, and engaged. His mood was stable, and his affect was flat. He had some difficulty expressing his thoughts, and he presented with delusions and possible visual hallucinations (ie, seeing a vacuum). The patient seemed to be minimizing his cognitive impairment by blaming it on his lack of sleep and age. According to the chart, there was some periodic incontinence. A right-sided resting tremor of the hand and arm was also observed.
The patient was administered the MMSE (total score: 24/30). He was mostly oriented (but not to date or year), with intact attention, and demonstrated motor difficulties. Dementia was suspected. Although he did not appear to be in delirium, given intact orientation and good attention, a superimposed delirium, given his new Parkinson disease medication, could not be ruled out. Neurology recommended an MRI scan of his brain. It was recommended that he not drive. It was also recommended that he be seen regarding a sleep evaluation and medication. He would ideally benefit from a comprehensive outpatient neuropsychological evaluation for dementia as the sensitivity of the MMSE (or similar cognitive measure) could not distinguish between dementia types, whereas an outpatient evaluation could seek to differentiate between Parkinson disease dementia, Lewy Body dementia, vascular dementia, normal pressure hydrocephalus, etc. in this highly educated man.
Case 3: Outpatient screening prompting a more comprehensive evaluation. A 42-year-old, right-handed, bilingual (L1: Spanish, L2: English) married Latin (Venezuela) identified male with 12 years of education was seen by outpatient rehabilitation (physical, occupational, and speech therapy) after suffering a cerebrovascular accident. His medical history was significant for hypertension, diabetes mellitus type II, hyperlipidemia, and loop recorder placement. MRI of the brain showed left parieto-occipital infarct, also involving the lenticular nucleus. The patient’s son reported that his father exhibited decreased memory, difficulty concentrating, trouble reading, and word-finding difficulties in both languages for which he was fluent. He also had a right homonymous hemianopsia. The patient denied any depression. He ambulated unassisted but with a slight limp.
Three months after the cerebrovascular accident, on an English administration of the Montreal Cognitive Assessment by the occupational therapist, the patient scored 21/30 points. He lost points on delayed recall (and was not helped with cueing), visuospatial tasks, fluency, and attention. The patient was recommended for a more comprehensive assessment to ascertain cognitive strengths and weaknesses and to determine whether he could return to driving. A bilingual neuropsychological evaluation conducted 5 months after the cerebrovascular accident revealed relative impairments in both verbal and visual learning and memory, visual and auditory attention, verbal fluency, naming, and complex comprehension (for all language functions--he was impaired for the acquired English language versus the more intact native Spanish ability), compared to estimated premorbid average ability. His family reported significantly increased executive dysfunction since the stroke, as well as increased apathy. Returning to occupational and speech therapies was recommended, as well as continuation of his not driving, with repeat testing in 9 to 12 months.
Case 4. An 83-year-old woman with a high school education residing in a rural southwest town consulted her general practitioner about feelings of depression. She had lost her job 2 years earlier during the COVID-19 pandemic due to workforce reductions, and since then, she only had limited social contacts. During this time, she had contracted COVID two times--once required a brief hospitalization to support and observe low oxygen levels. In addition to the common physical manifestations (eg, fever, cough, and fatigue), she also experienced anosmia and ageusia during the second illness. The latter had resolved in the span of a few weeks. Medical intervention with an antidepressant and individual therapy were initiated for a period of 8 months. Her blood tests were normal. Her brain MRI scan showed slight cortical atrophy.
On returning to her doctor, accompanied by one of her daughters, the medication seemed to have no effect. The children had noticed that their mother had difficulty finding the appropriate words, seemed to forget appointments, and often told the same stories, which was not typical of her personality during her adult life. Symptoms also gradually worsened during this time. She presented with a normal neurologic examination except for cognitive findings. Because Alzheimer disease was suspected, the Saint Louis University Mental Status examination was administered, and she scored 21/30 points. Orientation to the day was compromised, but she was otherwise oriented. Although attention and calculation were moderately disturbed and recall was slightly affected, language and visuospatial abilities were fully intact. Because conclusions about the individual elements of a patient’s cognitive function should not be based solely on the Saint Louis University Mental Status examination, she was referred for comprehensive neuropsychological testing of orientation, memory, attention, abstraction and executive function, language, visual perception, and visuoconstructive abilities. This resulted in a diagnosis of mild Alzheimer disease, and she then started treatment with a cholinesterase inhibitor. The Saint Louis University Mental Status examination was administered every 6 months during follow-up appointments, and scores initially improved to 24/30 points but then gradually declined to 16/30 over the subsequent 5 years. She was lost to follow-up for the last 3 years of her life, which were spent in a nursing home.
The mental status examination not only identifies brain disease but often points to the likely site of brain dysfunction. Functional specialization of different brain regions and pathways is evident; however, it must be noted that total segregation of behavior from the underlying neural mechanisms is never present, and the following conclusions should be read with this in mind. Additional considerations for changes in the structure and function of the brain based on developmental stage also must be considered when interpreting the results of mental status examinations.
Attention. Attention is thought to involve the reticular activating system, basal ganglia, and the frontal lobes. Abnormal performance is seen in disorders involving obtundation, in acute confusional states, and in severe dementias. Patients in acute confusional states or those with frontal lobe dysfunction tend to make errors of omission. Impulsive and anxious patients, such as those with ADHD, often make errors of commission.
Language. Disorders in language can represent focal lesions of the left hemisphere, especially focal cortical lesions. Abnormalities in comprehension usually occur in association with lesions of the posterior left hemisphere and are present in Wernicke aphasia. Impaired repetition occurs in patients with aphasic syndromes and is associated with lesions involving structures bordering the Sylvian fissure. Reading and writing are typically compromised by lesions of the posterior left hemisphere.
Visuospatial skills. Visuospatial deficits are seen in patients with focal brain lesions, as well as in those patients with degenerative brain disorders. Deficits are most marked when lesions involve the right posterior hemisphere, as seen in patients with unilateral neglect syndrome, but lesions may be present in many other locations (eg, the frontal, parietal, or occipital lobe of either hemisphere).
Memory. The impaired ability to learn new material is a diagnostic criterion for dementia and mild cognitive impairment. Patients who fail to learn verbal material may have damage to the fornix, the hippocampus, the mammillary body, the mammillothalamic tract, or the medial thalamus due to stroke, hypoxia, infection, Wernicke-Korsakoff syndrome, or tumors. Patients with intact learning but poor retrieval have such frontal-subcortical disorders as Pick disease, Huntington disease, tumor, stroke, trauma, or infection. Amnesia for nonverbal material may reflect pathology of the right temporal lobe or medial limbic structures.
Executive functions. Executive function involves frontal lobes and related subcortical structures as affected in Pick disease and Huntington disease.
All contributors' financial relationships have been reviewed and mitigated to ensure that this and every other article is free from commercial bias.
Lawrence H Pick PhD ABPP-CN
Dr. Pick of Gallaudet University has no relevant financial relationships to disclose.
See ProfileLynn A Schaefer PhD ABPP
Dr. Schaefer of Nassau University Medical Center has no relevant financial relationships to disclose.
See ProfileKerri A Scorpio PhD
Dr. Scorpio of Queens College of the City University of New York has no relevant financial relationships to disclose.
See ProfileJamie T Twaite PhD
Dr. Twaite of Burke Rehabilitation Hospital, Montefiore Health System, and Albert Einstein College of Medicine has no relevant financial relationships to disclose.
See ProfileErin Timperlake MA
Ms. Timperlake of Gallaudet University has no relevant financial relationships to disclose.
See ProfileRemington J Stafford BA
Mr. Stafford of Queens College of the City University of New York has no relevant financial relationships to disclose.
See ProfileJoan C Borod PhD ABPP-CN
Dr. Borod of Queens College of the City University of New York has no relevant financial relationships to disclose.
See ProfileVictor W Mark MD
Dr. Mark of the University of Alabama at Birmingham has no relevant financial relationships to disclose.
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