Familial hemiplegic migraine with crossed cerebellar diaschisis and unilateral meningeal enhancement.

A 6-year-old boy with a family history of hemiplegic migraine had a hemiplegic migraine lasting for 6 days complicated by prolonged fever, lethargy, and two brief focal seizures. An acute single photon emission computerized tomogram (SPECT) demonstrated decreased blood flow in the symptomatic cerebral hemisphere as well as crossed cerebellar diaschisis not previously documented in migraine. Another unique finding was the MRI with enhancement of the meninges and pial vessels over the symptomatic cerebral hemisphere. These findings suggest cerebellar and extra-axial involvement as components of hemiplegic migraine.