Surgical correction and SPECT imaging of vertebrobasilar insufficiency due to unilateral vertebral artery stenosis.

Incapacitating vertebrobasilar insufficiency is generally associated with bilateral vertebral artery disease, whereas unilateral vertebral artery stenosis usually is clinically silent. Regional brain perfusion has not been part of the routine evaluation of patients with vertebrobasilar insufficiency. This report describes two patients who had isolated unilateral vertebral artery stenosis operatively corrected to eliminate their incapacitating vertebrobasilar insufficiency. Hindbrain hypoperfusion was identified preoperatively and evaluated postoperatively, then correlated with patient presentation and response to revascularization.