Panic disorder: vascular evaluation with transcranial Doppler ultrasonography.

Several recent studies have shown neurophysiologic and neuroanatomic abnormalities in panic disorder. This study aimed to assess by transcranial Doppler (TCD) ultrasonography the magnitude of the changes in blood flow during panic attacks induced by intravenous sodium lactate infusion. The subjects consisted of 30 patients with panic disorder (DSM-III-R) and 25 controls; all were between the ages of 18 and 40 years and were right-handed. The flow in the middle cerebral artery was recorded bilaterally before the infusion began (to provide baseline readings) and at 3-minute intervals during the infusion. The patients showed a more rapid acceleration of flow (p less than 0.05) than the controls. Higher maximal velocity and higher variations in velocity (p less than 0.05) were observed in the patients sensitive to lactate but only in the right middle cerebral artery. These results suggest that abnormalities of local cerebrovascular autoregulation occurred in the patients with panic disorder during attacks induced by sodium lactate.