Cerebral hemodynamics in primary headaches: the transcranial Doppler experience.

This paper is an extensive review of the use of transcranial Doppler (TCD) devices in "vascular" forms of headache, and a discussion of the possible occurrence of nonunivocal results, particularly in migraine with or without aura. Despite the large variability in findings, TCD is a noninvasive, safe, and reproducible method for studying hemodynamic phenomena which characterize the clinical profile of migraine and cluster headache attacks. Similarly, it can detect cerebrovasomotor reactivity to external/internal environmental stimuli, as well as responses to pharmacological (therapeutic or diagnostic) agents. Possible future applications of TCD in monitoring vasomotor changes in response to selective stimuli (sympathetic, neuropeptidergic, etc.) are also considered.