Reduced Frequency of Prolonged Sporadic Hemiplegic Migraine Attacks Following Fremanezumab Treatment—A Case Report

INTRODUCTION: Hemiplegic migraine (HM) is a rare subtype of migraine with aura, characterized by transient, unilateral motor weakness. Due to its rarity, treatment strategies are lacking. Monoclonal antibodies targeting the calcitonin gene-related peptide (CGRP) pathway have emerged as a potential therapeutic option. CASE REPORT: A 64-year-old man was admitted to an Austrian stroke unit with acute aphasia, right-sided hemiplegia, and reduced consciousness. MRI showed no ischemia or hemorrhage. Cerebrospinal fluid analysis revealed pleocytosis (146 cells/μL) without signs of infection. By Day 4, the patient showed improving hemiparesis and new-onset hemicranial headache. Aphasia resolved by Day 14 and hemiparesis by Day 21. The patient's history included non-Hodgkin lymphoma with cerebral relapse, treated with whole-brain irradiation and stem cell transplantation in 2007, and a history of migraine with aura. Differential diagnoses such as SMART syndrome and HaNDL were considered, but the improvement of symptoms following headache onset and the prior migraine history supported the diagnosis of sporadic hemiplegic migraine (SHM). Genetic testing revealed no mutations associated with familial HM. Initial treatment with lamotrigine was followed by monthly fremanezumab (225 mg). No further HM attacks occurred over 6 months of follow-up. CONCLUSION: This case illustrates the diagnostic complexity of SHM and adds to the growing body of anecdotal observations suggesting that CGRP monoclonal antibodies may be a promising preventive treatment for patients with HM. Further studies are needed to evaluate their efficacy in this rare migraine subtype.