Prevalence and Risk Factors of Headache Associated with COVID-19.

Background: Headache is a prevalent and disabling non-respiratory symptom of COVID-19, posing a persistent challenge in post-COVID syndrome. This study aimed to determine the prevalence, phenotypes, risk factors and biomarkers associated with COVID-related headaches. Methods: A retrospective analysis of 634 hospitalized COVID-19 patients was conducted, with 295 participants being followed up 12-15 months post-discharge via telephone call. Initial laboratory workups, including complete blood count and various biochemical parameters, were compared between headache and non-headache groups. Results: One-third of hospitalized patients experienced headaches, predominantly younger individuals ( p < 0.001) and women ( p = 0.002). Non-dominant headaches were characterized as dull (56.9%) and holocranial (26.5%), while dominant headaches were unilateral (31.3%) with photophobia (34.3%) and nausea (56.3%). Persistent headaches were unilateral (40%) and pulsating (38%) with phonophobia (74%). Decreased CD4 T cells independently predicted COVID-associated headaches, with elevated IL-6 levels noted in the dominant-headache group ( p = 0.040). Remarkably, 50% of patients reported persistent headaches 12-15 months post-infection. Dexamethasone administration significantly reduced the likelihood of long-COVID headaches (52% vs. 73%, p = 0.029). Conclusions: Headache was present in one-third of patients with heterogenous phenotypes: tension headache in the non-dominant group, and migraine in the dominant and persistent headache groups. Persistent headache remains a challenge, with dexamethasone showing potential in reducing its incidence, emphasizing the need for tailored approaches in managing long-COVID headaches.