Bilateral common carotid artery occlusion with minimal neurological deficit: long term follow up in 3 patients.

Three patients, two women and one man, aged 56-70 year (mean 59 years) with modest neurological deficits and bilateral occlusion of the common carotid arteries initially identified by duplex scanning and angiography were followed by repeated clinical and transcranial Doppler examination (TCD) over 6.5 years. Vasomotor reactivity (VMR) was tested by combined examination of TCD and xenon-133 cerebral blood flow (CBF) before and after intravenous administration of 1 g acetazolamide. At follow-up CBF was measured using single photon emission computerised tomography (SPECT). In two patients mean velocities in the middle cerebral artery (MCA) were within the normal range at repetitive examinations with good VMR ranging 30-111%, whereas CBF was reduced in MCA territories ranging 29-36 ml 100 g(-1) min(-1), but increasing 44-69% after acetazolamide, indicating good VMR. These 2 cases had anterograde flow in the ophthalmic artery and siphon. The third patient had very low MCA mean velocities of 21-27 cm sec(-1), increasing 26-33% after acetazolamide. This patient had retrograde flow in the ophthalmic artery and siphon connected with bilateral prolonged episodes of amaurosis fugax and transient ischemic attacks. In all three patients the posterior cerebral arteries were major supplying collaterals having high mean velocities of about 100 cm sec(-1) and high velocities in the basilar arteries of 85 cm sec(-1) as well. During follow up no patient had a new stroke, but all experienced orthostatic dizziness and chronic fatigue.