(Kiosk 1) Post Traumatic Nummular Headache Treated with Off-label Onabotulinum Toxin A: A Case Report

Case Diagnosis: Patient suffered head trauma and developed post traumatic nummular headache.

Case Description or Program Description: Patient 1: A 41 year-old male service-member experienced blunt trauma to the top of his head caused by striking his head on a door frame as he was exiting a military vehicle. He was diagnosed with traumatic brain injury and experienced post traumatic headaches. He localized these headaches as originating from the top of his head and radiating to his scalp with a dull characteristic. These headaches were associated with photosensitivity and nausea. Brain MRI was without significant structural findings and he was treated with agents including magnesium, amitriptyline, verapamil, and diphenhydramine with minimal relief.

Setting: Outpatient Veterans Affairs clinic

Assessment/Results: Five years after his initial evaluation, he was treated with fixed site and fixed dose (FSFD) onabotulinum toxin A (OBA) injections. Three weeks after treatment, the patient experienced a month of relief followed by a reduced headache intensity of 3-5 on visual analog scale. On repeat FSFD injection visit, patient received an additional 7.5 units to the crown of his head in a follow-the-pain (FTP) pattern. One week later, he experienced no headaches for two months. Subsequent FSFD injections performed in 3-4 months intervals resulted in similar headache relief.

Discussion (relevance): Post traumatic headaches are one of the complications following mild traumatic brain injuries. A subcategory of headaches, known as nummular headaches, are described as being round or elliptical shaped, are typically idiopathic, and in a few cases have been precipitated by head trauma. Prior studies have suggested that onabotulinum toxin A, given in FSFD pattern, provides effective symptom control for post traumatic headache patients. Our patients’ headaches follow a pattern characteristic of nummular headaches and responded to treatment with standard FSFD OBA. He experienced greater symptom relief with the addition of FTP dosing.

Conclusions: Nummular headaches are a potential a complication of mild traumatic brain injury. This category of secondary headache may benefit from off-label, focal OBA injections in a FTP pattern in addition to the standard FSFD pattern utilized for chronic migraine therapy.