Department of Neurology, Germantown Hospital and Medical Center, Philadelphia, Pennsylvania.
Abstract:
This article reviews the technique and physics relevant to a functional understanding of transcranial doppler. The frequently contradictory findings in migraine are reviewed. Several studies suggest increased flow velocities are common in the interictal period. There are disparate findings between studies of the ictal period. In cluster headache, there appear to be more easily reproduced changes between and during cluster attacks.