A 12-year-old girl presented with headache, nausea, decreased level of consciousness, and diplopia. Brain MRI, arteriography (figure e-1 on the Neurology® Web site at www.neurology.org), vasculitic markers, and CSF were normal, as were EEGs and ECGs. Transcranial color-coded ultrasonography of the basilar artery revealed typical musical murmurs ("seagull cry") indicative of a hemodynamically significant stenosis (video).(1) Sumatriptan provided symptomatic relief; basilar flow normalized on ultrasonography (figure e-2). The clinical presentation suggested childhood migraine with aura; the ultrasound and normal arteriography suggested focal, transient vasospasm during a migraine attack. Topiramate was effective long-term. The high prevalence of childhood migraine (up to >20%)(2) suggests that ultrasound may be a useful diagnostic tool.