Clinical manifestations

Presentation and course

Primary stabbing headache is characterized by brief, sharp, severe jabbing pains about the head that occur either as single episodes or as brief repeated volleys. The International Classification of Headache Disorders (ICHD) has formulated criteria for this diagnosis (Table 1) under the term 4.7 “primary stabbing headache” (10). The pain resembles a stab from an icepick, nail, or needle and typically lasts from a fraction of a second to 1 to 2 seconds. Primary stabbing headache may have the shortest duration of all known headaches. The frequency of attacks varies immensely, ranging from one attack per year to 50 attacks per day. The pain was originally believed to be isolated to the distribution of the trigeminal nerve; however, studies showed about 53% to 80% of patients with primary stabbing headache had stabs over extratrigeminal location (14), and the diagnostic criteria of ICHD-3 has removed this location requirement for diagnosis. Icepick-like pains are more common in women and do occur in children (01).

Table 1. ICHD-3 Diagnostic Criteria for Primary Stabbing Headache

Most stabs last 3 seconds or less; rarely, stabs last for 10 to 120 seconds (08). These pains are usually unilateral but may be bilateral. They occur mainly around the parietal region (44.4%), followed by the frontal region (21.5%) and occipital region (13.9%) (22). Attacks usually recur in the same area. If they occur in patients with other types of headache, they are characteristically located on the same side and frequently at the same site of the customary headache.

The attack frequency is generally low, with one or a few per day. Great variability exists in the temporal pattern of attacks. Most patients experience only single jabs, although some may have volleys of jabs. Attacks may be experienced as often as 50 times per day.

Approximately 38% to 74% of patients experience jolts, which are sudden movements that occur along with stabs (08; 12). In 18% of patients, vocalization has also been reported (08). Clinical-based studies have reported allodynia in 19% to 37% of patients (08; 16; 12). Accompanying phenomena, such as tearing, eye redness, or nausea, are absent.

A few patients, particularly those with comorbid migraine, have reported precipitating triggers for their idiopathic stabbing headaches. These triggers include rapid alterations in posture, physical exertion, bright light, and head motion during migraine attacks (20). In most patients, however, the pain is unprovoked.

Ammache and colleagues described a 27-year-old man with primary stabbing headache associated with monocular visual loss with scintillating scotoma ipsilateral to the pain (02). The patient had a history of migraine with aura.

Ahmed and colleagues reported on 42 children and adolescents with primary stabbing headache (01). Their mean age was 12 years. Most stabs were located in the extra-trigeminal regions. The frequency of the stabs ranged from daily to monthly. The presentation and nature of primary stabbing headache in children and adolescents vary widely. A family history of primary stabbing headache was identified in two patients in this cohort.

In another cohort of 77 children and adolescents with primary stabbing headaches, 16.9% were younger than 6 years of age at presentation (31). The location of the headache was frontal in 54.5% of patients and bilateral in 68.8%.

Prognosis and complications

Primary stabbing headache is considered to be a benign condition, which may remit with time. In patients with infrequent attacks, education on the disorder may be sufficient, and medication may not be necessary. In patients on prophylactic treatments, periodic attempts to taper medication are reasonable to evaluate for possible remission.

It is hard to prognosticate about primary stabbing headache because of the great temporal variability. However, Kim and colleagues attempted to do so by prospectively screening and following patients diagnosed with primary stabbing headache in their clinic between June 2015 and March 2016 (12). They were able to identify 65 patients and found that most individuals followed one of three possible courses: a monophasic (n=31), intermittent (n=17), or chronic daily (n=12) pattern. Patients with a monophasic disease course tended to experience a duration of about 9 days, with attacks being of greater severity, occurring singly but with multiple attacks per day, side-locked attacks, and responding well to treatment. Patients with an intermittent pattern were more likely to be women and would experience symptoms on average for 2 years, with stabs being sporadic and of variable intensity. Chronic daily primary stabbing headache tended to last for 9 months, was more likely to occur in women, and presented with attacks that were longer-lasting and could change locations over the head. This study was the first to prospectively look at the clinical course of primary stabbing headache, and with the identification of three different typical patterns, hopefully, future research will help clarify etiology and help optimize treatment strategies.

Clinical vignette

Patient 1. A 64-year-old man started having headaches 5 years prior. The pain was usually felt over the left temporal region. It lasted less than a second and was described as a sharp pain, stabbing in nature. Other areas were also affected by the stabs, including the left and right parietal regions and the right occipital region. He had 6 to 12 stabs a day. No accompanying symptoms were associated with the pain. Physical and neurologic examinations were normal. MRI and MRA of the brain were also normal. The patient was put on indomethacin 25 mg, three times a day, with significant improvement in headache frequency; however, the medication was not well tolerated. Specific cyclooxygenase-2 inhibitors were then tried with good relief.

Patient 2. A 58-year-old woman started to complain of sudden pain in the right frontoparietal region for 3 weeks. The sudden stabs of pain, lasting about one minute, were very severe, always frightened the patient, and were followed by vocalization. She reported two to three episodes per day, without autonomic symptoms or any other manifestation in the beginning but the attacks increased progressively. Indomethacin 25 mg three times per day was started, but she still had frequent attacks. Celecoxib 100 mg twice daily was prescribed, but it was not effective. The brain MRA showed an aneurysm over right posterior communicating artery.

Biological basis

Etiology and pathogenesis

Stabbing headache may occur as a primary entity but is often also associated with another headache type and can occur secondary to other disorders.

Piovesan and colleagues reported stabbing headaches secondary to cerebrovascular disorders (24). Two women and one man, 76 years of age, 66 years of age, and 72 years of age, respectively, developed headaches within 20 days after stroke. All patients responded to celecoxib, a cyclooxygenase-2 inhibitor.

The mechanism of primary stabbing headache is unknown. The potential mechanism includes irritation of trigeminal and extra-trigeminal nerves and intermittent impairment of central pain processing leading to hyperexcitability of neurons or spontaneous synchronous discharge of neurons. Ice pick pains may result from spontaneous discharges of trigeminal afferent fibers. Subpial grey matter and meningeal inflammation might sensitize trigeminal sensory fibers and lead to spontaneous activity of trigeminal branches (13). Further studies are necessary to determine the pathogenesis and pathophysiology of idiopathic stabbing headache.

Epidemiology

The reported prevalence of primary stabbing headache ranges from 0.2% to 35% (20). The range may be due to different study settings and referral bias. In one study, 26.7% of neurologists experience primary stabbing headache over their lifetime, ensuring high diagnostic accuracy (11). In the adult population, primary stabbing headache occurs more commonly in women, with a female-to-male ratio of 1.49-6.6 to 1 (20). In children and adolescents, there is no gender predominance (09). The mean age of onset was around 28 years in a community-based study and 48 years old in a clinic-based study (37).

Sjaastad and colleagues studied the prevalence of idiopathic stabbing headache in the general population (the Vaga study) (33). In that study, conducted in Vaga, Norway, 1838 adults, 18 to 65 years of age, were examined. Jabs and jolts syndrome or idiopathic stabbing headache was diagnosed in 35.2% of the population. The female-to-male ratio was 1.49. They also studied extracephalic “jabs.” Three women had facial jabs, and one of them had pain spreading to the head. Four subjects had jabs occurring randomly throughout the body, including the cephalic area. Pure nuchal jabs were present in 12 subjects, 10 of whom were males. The characteristics of the extracephalic jabs were not different from the cephalic ones (34).

Primary stabbing pain occurs more commonly in individuals who have migraine (27; 23). Primary stabbing headache may also occur in many other headache disorders, including tension-type headache, hemicrania continua, and cluster headache, with a reported prevalence ranging from 21% to 84% in these other disorders (38; 09).

Differential diagnosis

Trigeminal neuralgia involving the first division of the trigeminal nerve is a differential diagnostic possibility. The existence of trigger points, such as brushing teeth, eating, speaking, and the distribution of pain, occur mostly in maxillary and mandibular trigeminal nerve branches and are valuable distinguishing characteristics (ICHD-3).

Patients with SUNCT or SUNA (short-lasting unilateral neuralgiform headache attacks with cranial autonomic symptoms) complain of unilateral headache with frequent (5 to 30 times per hour), short-lasting (15 to 60 seconds) attacks of pain in the V1 distribution (ICHD-3). The pain typically occurs in and around one eye and is accompanied by ipsilateral conjunctival injection, lacrimation, or other ipsilateral autonomic symptoms. The presence of accompanying autonomic changes is diagnostic. It is possible to differentiate primary stabbing headache from SUNA/SUNCT if cranial autonomic symptoms are not observed.

Attacks of chronic paroxysmal hemicrania have pain characteristics and associated autonomic symptoms and signs similar to those of cluster headache, but the attacks of pain are short-lived (ICHD-3). These headaches can be distinguished from primary stabbing headache because the bouts of paroxysmal hemicrania generally last between 5 and 30 minutes and are associated with autonomic symptoms, such as ipsilateral lacrimation or rhinorrhea.

In occipital neuralgia, pain is distributed within the dermatome of the occipital nerve branch, whereas the pain is more focal in primary stabbing headache (14). Dysesthesia, allodynia, and tenderness in the affected nerve branch are more often associated with occipital neuralgia than primary stabbing headaches. Primary stabbing headache and occipital neuralgia can be differentiated with the help of a diagnostic nerve block (14).

Nummular headache is a coin-shaped range from 1 to 6 cm head pain. The parietal area is the most common location of pain, followed by the occipital region (06). The intensity of pain is mild or moderate and the duration continuous or intermittent. The most common characteristic of pain is pressure-like (44.4%), followed by stabbing pain (16.7%) and burning pain (12.5%) (22). Nummular headache is characterized by a clearly demarcated pain area as well as accompanying focal tenderness or sensory abnormalities within the pain area sometimes, which distinguishes it from primary stabbing headache (06).

Diagnostic workup

A careful history and a normal examination are often sufficient to make the diagnosis. However, it is reasonable to do some neuroimaging, either an MRI or CT of the brain, as encephalitis, neoplasm (cerebral or pituitary), vasculitis (ie, giant cell arteritis), acute thalamic hematoma, cerebral aneurysms, and arteriovenous malformation can present as a stabbing headache (28; 36). Pituitary tumor, meningioma, and vestibular schwannomas were the most prevalent types of intracranial neoplasms for secondary stabbing headache (36). Valenca and colleagues identified that recent onset of stabbing headache, exclusively unilateral at the same location; crescendo pattern, triggered by head movements; or Valsalva maneuver were red flags for secondary stabbing headache (36). Recommendations for the diagnostic workup of headache with any phenotype, including isolated stabbing headache, should still presumably follow accepted recommendations to rule out secondary causes in the presence of red flags (28; 36).

Rampello and colleagues examined 26 patients with stabbing headache and found that 14 had an autoimmune disorder (26). Stabbing headache in patients with giant-cell arteritis has been reported (30). It is reasonable to check the erythrocyte sedimentation rate and C-reactive protein in patients older than 50 years of age presenting with new-onset stabbing headache. Unless there is other evidence of autoimmune disorder, it is low yield to extensively check the autoimmune survey.

Management

Given the sudden onset and short duration of these attacks, acute treatment is not practical. When attempting to manage patients with frequent attacks of primary stabbing headache, a prophylactic medication needs to be used.

Primary stabbing headache is classified as an indomethacin-responsive headache disorder (20). The vast majority of patients tend to quickly respond to indomethacin 75 to 150 mg/day, taken in divided doses. In most case series, indomethacin yields 30% to 50% success in achieving complete remission (21; 08; 12). Indomethacin has a few unique properties compared to other NSAIDs, including the inhibition of nitric oxide release (07), which may explain why some headache disorders including primary stabbing headache respond exquisitely to this specific NSAID. The adverse events of indomethacin include dyspepsia, gastrointestinal bleeding, and renal toxicity.

In patients who cannot tolerate or do not respond to indomethacin, reasonable alternative treatments are gabapentin, melatonin, celecoxib, other COX-2 inhibitors, onabotulinumtoxin A (BoNTA), topiramate, acetazolamide, and nifedipine (29; 25; 20). Amitriptyline was used successfully in two pediatric patients with primary stabbing headache (19).

One systemic review of melatonin for primary headache (not specific for primary stabbing headache) included only four randomized controlled trials with poor methodological quality (351 participants) (17).The results showed that evidence is lacking for melatonin as first-line therapy, but it may be a treatment option in difficult headache cases or pediatric primary headaches in the short term (17). The structure of melatonin is similar to indomethacin, but its adverse events are fewer and include dizziness, nausea, and vomiting (03).

Outcomes

The majority of cases of primary stabbing headache are benign and self-limiting (14). Compared to patients with pain in multiple locations, patients with pain in fixed locations responded better to treatment (05).

Special considerations

There has been a case report from Colombia of a 7-year-old boy with primary stabbing headache (04). His attacks did not respond to coenzyme Q10 100 mg twice daily but stopped after the initiation of melatonin 1.5 mg at bedtime (0.07 mg/kg). Improvement was seen within the first 2 weeks of starting melatonin. At the 6-month follow-up visit, there was sustained benefit and good adherence, with no adverse effects. The authors concluded that melatonin is a reasonable treatment for primary stabbing headache in the pediatric population.