Headache comorbidity in epilepsy and functional/dissociative seizures: an exploratory cross-sectional study in a tertiary epilepsy center

TL;DR

This study explores the link between headaches and epilepsy or functional seizures, finding that headaches are more common in functional seizure patients and highlights the need for better screening.

Contribution

The study identifies distinct associations between headache disorders and epilepsy subtypes or functional seizures, emphasizing the importance of systematic headache screening in clinical practice.

Findings

Functional/dissociative seizures are positively associated with headache and migraine compared to epilepsy.

Migraine prevalence is higher in younger and female patients, with specific associations to seizure localization and medications.

Levetiracetam and valproic acid use are negatively linked to migraine, while frontal seizure onset is negatively associated with migraine.

Abstract

Headache disorders are common in patients with epilepsy and functional/dissociative seizures (FDS) and may influence quality of life and clinical outcomes. Migraine has been proposed as a reciprocal risk factor for epileptic and functional seizures. We aimed to determine the prevalence of headache disorders and associated clinical factors in a cohort of patients undergoing video-EEG monitoring at a tertiary epilepsy center.

In this retrospective cross-sectional study, clinical data from 164 adult inpatients evaluated in an epilepsy monitoring unit were analyzed. Headache diagnoses were established using a structured interview based on International Classification of Headache Disorders (ICHD-3) criteria. Associations between headache disorders and clinical variables – including epilepsy subtype, seizure localization, antiseizure medication (ASM), and pre-existing illnesses – were assessed using Fisher’s exact tests and logistic regression analyses.

Seventy percent of patients were diagnosed with epilepsy and 13% with FDS. Among epilepsy patients, 48% reported headache (21% migraine, 18% tension-type headache), whereas 77% of patients with FDS reported headache (50% migraine, 14% tension-type headache). Epilepsy overall, particularly lesional focal epilepsy, was negatively associated with headache and migraine compared with no-epilepsy patients. In contrast, FDS was positively associated with headache and migraine. Migraine with aura was not disproportionately represented in epilepsy or FDS. Female sex and younger age were associated with headache. Levetiracetam and valproic acid use were negatively associated with migraine. Frontal seizure onset was negatively associated with migraine, whereas temporal onset showed a non-significant positive trend. Obesity was positively associated with migraine with aura, while depression showed a negative association with migraine.

Headache disorders are frequent in patients undergoing evaluation for paroxysmal neurological disorders, particularly in FDS. Systematic headache screening—especially in young and female patients—may help reduce disease burden. Further studies should clarify shared mechanisms and potential therapeutic implications.

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