Functional neurological seizures and migraine: A systematic review and case series

•There is growing evidence supporting an association between migraine and functional neurological disorder (FND) seizures.•Changes in awareness and vestibular symptoms seem to be more prevalent in functional neurological disorder seizures that are triggered by migraine than those triggered by other factors.•Both functional neurological disorder seizures and headaches may improve with the use of migraine prophylaxis. The seizure subtype of functional neurological disorder (FND-seizures) is a common neuropsychiatric condition manifesting with episodic epilepsy-like events. Despite the common belief that FND-seizures are precipitated by psychological stressors, neurological disorders may also be triggers. In 1890, Babinski described four cases of FND symptoms associated with migraine attacks. Despite the passing of more than 130 years since this first clinical observation, the relationship between FND-seizures and migraine is not fully elucidated. (1) To complete a systematic review of the literature that investigated potential associations between FND-seizures and migraine and the response of FND seizures to treatment with migraine prophylactic medications (2). To undertake a retrospective study of patients with FND-seizures and migraine, including response to migraine prophylaxis. (1) Using PRISMA methods, we completed a systematic review of EMBASE and Scopus databases from inception to March 31, 2021, for literature on FND-seizures and migraine. (2) Our multi-disciplinary team, including subspecialists in psychosomatic medicine, epilepsy, and headache disorders, reviewed consecutive patients diagnosed with FND-seizures and migraine to assess potential causal associations and responses to standard migraine prophylactic medications. (1) The search yielded seven studies from 126 screened manuscripts (N = 1,186 patients with FND-seizures; mean age 38.7 years; 72.6% female). They varied substantially in design, population, diagnostic measures, and outcomes. Nevertheless, all studies found associations between FND-seizures and migraine, which were stronger than those between epileptic seizures and migraine in comparative investigations, but provided limited information on treatment response. (2) In our case series, investigators reached unanimous consensus that migraine attacks triggered FND-seizures in 28/43 (65.1%) patients reviewed (mean age, 38.8 years; 74% female). In 19/26 (73%) patients with adequate follow-up data, treatment with migraine prophylactic me