Arterial Spin Labeling Magnetic Resonance Imaging in Hemiplegic Migraine: A Noninvasive Tool for Cerebral Perfusion Assessment

A bstract Arterial spin labeling (ASL) magnetic resonance imaging (MRI) is an emerging noninvasive perfusion imaging technique increasingly used in the evaluation of hemiplegic migraine (HM). HM is a rare migraine subtype characterized by transient unilateral motor weakness associated with aura, often mimicking acute ischemic stroke. ASL measures cerebral blood flow without exogenous contrast, allowing dynamic assessment of perfusion changes during attacks. In the acute phase, ASL commonly reveals reversible regional hypoperfusion, involving the cortex corresponding to neurological deficits. These perfusion abnormalities evolve over time and typically normalize with symptom resolution. Here, we describe a 13-year-old girl, who presented with an acute onset of right upper limb paresis and was subsequently diagnosed with HM with genetic confirmation. ASL-MRI provides a valuable, repeatable tool to characterize perfusion alterations in HM and differentiate HM from stroke, guiding appropriate management in emergency and follow-up settings.