Epicranial headaches part 2: Nummular headache and epicrania fugax

BACKGROUND

Nummular headache and epicrania fugax are two primary headaches that fall under the heading of epicranial headaches.

METHODS

This article reviews the epidemiological and clinical features of nummular headache and epicrania fugax, proposed pathogenic mechanisms and state-of-the-art management, according to the literature.

RESULTS AND CONCLUSIONS

Nummular headache and epicrania fugax are generally viewed as rare headache disorders, but no population-based epidemiological data are available. Nummular headache is characterized by continuous or intermittent head pain, which remains circumscribed in a round or oval area of the scalp, typically one to six centimeters in diameter. Epicrania fugax manifests with brief paroxysms of pain that move along the surface of the head, following a linear or zigzag trajectory through different nerve territories. Nummular headache and epicrania fugax are mostly primary headaches, but some secondary cases have been reported. The pathogenesis of these headaches is not fully understood. Nummular headache could probably originate in epicranial tissues or adjacent intracranial structures, while the origin of epicrania fugax could be extracranial or intracranial. Diagnostic assessment requires careful examination of the symptomatic areas. Underlying disorders should be excluded by additional investigations, including neuroimaging and appropriate blood tests. No controlled clinical trials have been conducted in nummular headache or epicrania fugax. Analgesics and anti-inflammatory drugs, botulinum toxin and gabapentin are currently the most recommended treatment options for nummular headache. In epicrania fugax, the most used treatments are gabapentin, lamotrigine, and other antiseizure medications.

Anatomical Study of the Posterior Spinal Artery Branches to the Medulla Oblongata

BACKGROUND

The posterior spinal arteries (PSAs), branches of the intracranial segment of the vertebral artery or posterior inferior cerebellar artery, run bilaterally along the spinal cord and are integral to the blood supply primarily to the posterior one third of this structure. However, a less well-described distribution of the PSAs is their supply to the posterior medulla. The purpose of this study is to examine the medullary branches of the PSA anatomically.

METHODS

We conducted a cadaveric study to evaluate for branches of the PSA supplying the medulla oblongata.

RESULTS

All 14 sides had medullary branches arising from the PSAs. The average number of branches supplying the medulla oblongata on each side was 6. Most of these branches traveled laterally to anastomose with medullary branches arising from the anterior spinal artery. Additionally, lateral and ascending branches were noted.

CONCLUSIONS

Physicians who interpret imaging of the craniocervical junction, in particular arteriograms, should be aware of ascending medullary branches arising from the anterior spinal artery. Additionally, neurosurgeons operating this region must be careful in dissecting over the posterior medulla and manipulating the cerebellar tonsils, as in telovelar approaches to the fourth ventricle, in order to avoid iatrogenic injury to these vessels. Additionally, variable stroke patterns involving the vertebral artery or posterior inferior cerebellar artery might include ischemia to the medulla oblongata via PSA branches, and this anatomy should be kept in mind by interventionalists, radiologists, and neurologists alike.

Epicrania fugax: Report of eight cases with some novel features

Introduction:

Epicrania fugax (EF) is an epicranial headache syndrome characterized by short lasting headache paroxysms which spread in a typical linear/zigzag pattern. The definition of EF has evolved over time, and new phenotypes have been observed in various studies.

Aim:

We present eight cases diagnosed as EF according to the International Classification of Headaches Disorders, 3rd edition criteria and highlight certain novel characteristics which will help in the further categorization of this disorder.

Methods:

We prospectively studied eight cases of EF who presented to our headache clinic from January 2016 to September 2020. Demographic and detailed clinical data were collected and analyzed.

Results:

The mean age of onset of the cohort was 42 ± 10.47 years with a median duration of symptoms being 1 year. There were 5 male and 3 female patients. The mean visual analog scale score was 5.25 ± 1.83. Headache frequency had high intra and interindividual variability. Four patients had a typical spread of pain along the distribution of greater occipital, and supraorbital, nerves. Four patients had an atypical presentation with midline headache, transverse occipital, and bilateral simultaneous hemicranium involvement. Headache paroxysm was followed by a prolonged fixed pain in the same linear distribution in three patients. One patient had ipsilateral redness in the eye. All eight patients required medical intervention with amitriptyline or neuromodulators, five of whom reported a significant reduction in their headache symptoms.

Conclusion:

Our case series highlights a few interesting features which need further exploration with larger studies. Firstly, the atypical distribution of the pain trajectory forces us to dig deeper into the pathogenesis of the disorder. Secondly, our data also suggest a possibility of EF triggered “linear headaches.” EF is a relatively uncommon headache disorder that can be managed easily with neuromodulators but the lack of awareness of the condition often leads to delayed diagnosis.

Paroxysmal headache with extracephalic irradiation: Proposal for a new variant of epicrania fugax in a series of five patients

Background

Epicrania fugax consists of brief paroxysms of pain, which radiate in a line or in zigzag trajectory across the surface of the scalp or the face.

Methods

A prospective, descriptive study was performed in five patients presenting with an epicrania fugax-type pain with extracephalic irradiation.

Results

All patients were women, and the mean age at onset was 59.8 (standard deviation, 10.9). They had unilateral paroxysms of electrical pain starting at a particular point in the head (parietal, n = 3; vertex, n = 1; frontal, n = 1) and rapidly radiating downwards in a lineal trajectory to reach extracephalic regions (ipsilateral limbs, n = 2; shoulder, n = 2; low neck, n = 1) in 1–3 seconds. Pain intensity was moderate or severe. Three patients had nummular headache at the point where the paroxysms originated. One patient had spontaneous remission, and four patients achieved complete or almost complete response with therapy (onabotulinumtoxinA, n = 2; indomethacin, n = 1; amitriptyline, n = 1; lamotrigine, n = 1).

Conclusion

The spectrum of epicrania fugax may include paroxysms with extracephalic irradiation. The propagation of pain beyond the head and the face supports the involvement of central mechanisms in the pathophysiology of this entity.

Epicrania Fugax as the presenting symptom of a cerebellar abscess

Background

Epicrania fugax is included in the appendix of the International Classification of Headache Disorders and is characterized as recurrent brief attacks of linear or zigzag pain moving across the cranial surface, commencing and terminating in the distribution of different nerves. We present a new case of epicrania fugax in which the headache was the presenting symptom of a cerebellar abscess.

Case report

We present a 58-year-old woman with prior history of Chiari I malformation who underwent suboccipital craniectomy. Two weeks after surgery, she experienced paroxysmal pain episodes of 1–3 seconds, with constant linear trajectory from the right occipital surface to the right orbital region, remaining pain free between episodes. Cranial tomography showed a hypodense intraaxial lesion in the right cerebellar hemisphere. Magnetic Resonance Imaging exhibited intralesional bleeding and peripheral enhancement after gadolinium administration. Post-surgical cerebellar abscess was diagnosed and antibiotic therapy was started; the patient underwent urgent surgical drainage. Pain disappeared after the surgery and the patient remains pain free with 12 months of follow-up.

Conclusion

Posterior fossa abnormalities have been described as a possible cause of secondary epicrania fugax. The presence of red flags should encourage conducting of paraclinical tests to rule out a symptomatic form.