Recent advances in functional neuroimaging.

New functional imaging techniques, including positron emission tomography, transcranial magnetic stimulation and functional magnetic resonance imaging, promise to allow the noninvasive study of haemodynamic, metabolic and activation parameters during acute migraine attacks in humans. These techniques are currently being applied to the study of the transient neurologic symptoms of the aura, as well as the painful headache phase of migraine. This review summarizes the most recent of these studies and discusses how they relate to the prevailing theories of migraine pathophysiology.