Neurovascular Reactivity in Patients with Acute Ischemic Stroke

Abstract

OBJECTIVE: We aimed to assess the motor evoked blood flow velocity (BFV) changes in both middle cerebral arteries (MCA) using transcranial Doppler (TCD) monitoring in patients with acute ischemic strokes and healthy subjects. METHODS: Eighty-two patients with acute territorial infarction in the MCA territory, 83 patients with acute lacunar infarction in MCA territory and 21 control subjects were investigated. A long term TCD monitoring device was used for the simultaneous recording of both MCA during 10 cycles of 20 seconds while the subjects performed hand gripping with a frequency of one per second, and subsequently 20 seconds when they were resting to assess BFV changes on activated cortical motor areas. Neurovascular reactivity was defined as a relative increase in blood flow velocities which were calculated as the percentage change in baseline value. RESULTS: Hand gripping showed a marked rise in the blood flow velocities in both MCAs in all subjects (p<0.001 for all vessels). Patients with territorial infarction had significantly lower neurovascular reactivity (15.0%±9.5) than those of patients with lacunar infarction (19.9%±11.5 p<0.007). CONCLUSION: Our results suggest that unilateral cerebrovascular ischemic events can affect blood flow in both MCAs in patients with acute ischemic events in the MCA territory, and neurovascular reactivity was preserved in patients with lacunar stroke in contrast to territorial stroke.