Multimodal neuroimaging in a child with sporadic hemiplegic migraine: A contribution to understanding pathogenesis

Background: Hemiplegic migraine (HM) is a rare variety of migraine with aura, characterized by motor deficits during the aura, often beginning in childhood. The hemiplegic attacks can be severe and prolonged but the prognosis is usually good. Data on neuroimaging, including diffusion-weighted imaging (DWI) and spectroscopy, during prolonged attacks of HM are quite limited, particularly in children. Case: An eight-year-old female had a prolonged attack of sporadic HM characterized by right-sided hemiplegia, global aphasia, fever and impairment of consciousness. MRI nine hours after hemiplegia onset was negative, while the following MRI scans (days 4 and 11) documented a progressive increase in cortical swelling in the left hemisphere with mild hyperintensity on DWI and mild reduction of apparent diffusion coefficient values. Proton MRI spectroscopy (MRS) (day 15) showed a decrease in the N-acetylaspartate/creatine ratio in the left hemisphere. Tc-99m-ECD single-photon emission tomography (SPET) (day 27) showed marked left hemispheric hypoperfusion. The patient recovered completely after 40 days and neuroimaging follow-up (MRI and SPET) after six months was normal. The patient carried a missense mutation of the ATP1A2 gene. Conclusion: Multimodal neuroimaging (MRI, DWI, MRS, SPET) in a prolonged HM attack supports evidence for a primary neuronal dysfunction.