LETTERS Prolonged hemiplegic migraine associated with unilateral hyperperfusion on perfusion weighted magnetic resonance imaging

Hemiplegic migraine (HM) is an unusual subset of migraine with aura, in which headache is associated with unilateral motor deficits, thought to be attributable to an underlying calcium channelopathy. In some cases the neurological dysfunction may outlast the headache and persist for many days. In the initial stages, hemiplegic migraine may mimic cerebral infarction. Within the first few hours after stroke, both computed tomography and magnetic resonance imaging (MRI) are often normal. However, more information can be gained using diffusion (DWI) and perfusion weighted imaging (PWI), which are much more sensitive to acute events in cerebral ischaemia. A recently reported postprocessing technique (factor analysis of dynamic studies FADS) can be applied to PWI to generate images representing arterial (“early”) and venous (“late”) contributions to signal intensity. This report outlines the findings arising from the application of multimodal MRI techniques to a patient with prolonged hemiplegic migraine.