Abstract
Background Headache can be a prominent feature of Post-Acute Sequelae of SARS-Cov2 infection (PASC) and previous studies have centered around PASC headaches that have resolved within a month of infection. Methods We performed a retrospective chart review of 31 adults evaluated at the Stanford Headache Clinic between September 2020 and January 2022 who developed new or worsening headaches after COVID-19 infection that were unresolved at time of evaluation for demographics, medical history, and headache diagnosis. Results Headache had been present for a mean duration of 7.4 +/- 4.8 months after infection. Notably, 25/31 (81%) had a previous history of headache. The specific features of the headache varied considerably, but 23/31 (74%) met International Classification of Headache Disorders, Third Edition (ICHD-3) criteria for migraine, with 20/31 (65%) meeting ICHD-3 criteria for chronic migraine, while only 5/31 (16%) met these criteria before COVID infection. Additionally, full-time employment decreased from 25/31 (81%) to 17/31 (55%). Prior to establishing care at our clinic, 13/18 (72%) of the patients who were started on preventive medications currently indicated for migraine management, reported a decrease in frequency and/or severity of headaches. Conclusions Our study presents a group of patients with protracted headache after COVID-19 infection that includes both patients with a previously lower headache burden who largely exhibited chronification from episodic to chronic migraine, as well as patients with no previous history of headache who meet ICHD-3 criteria for headache attributed to a systemic viral illness, mostly with a migrainous phenotype.