Blood Flow Velocity Patterns on Transcranial Doppler Ultrasonography in Patients with Moyamoya Disease.

This study included 17 patients (5 men and 12 women) with a clinical diagnosis of moyamoya disease from conventional angiograms. Bilateral basal arteries were measured by the transtemporal approach with a 2-MHz pulsed Doppler instrument (TC-2 64B, EME) . Reliable TCD recordings were obtained in 28 out of 34 basal arteries (82.4%) . These TCD findings were classified into three patterns : 1) high-high pattern; the mean cerebral blood flow velocity (CBFV) was increased throughout the basal arteries by over 70 cm/s (7 arteries, 25.0%), 2) high-low pattern ; the mean CBFV was fastest (over 70 cm/s) at the ICA or proximal MCA, and the mean CBFV was markedly decreased distally (15 arteries, 53.6%), and 3) low-low pattern; the mean CBFV was less than 40 cm/s throughout the basal arteries (4 arteries, 15.4%) . The high-high pattern on TCD was seen predominantly in younger patients and those in the earlier stages of the disease. The high-low pattern was the most common one of CBFV as assessed by TCD in moyamoya patients. The low-low pattern on TCD was more common in the later stages following angiographic evaluation by Suzuki's criteria.The above patterns based on TCD findings show good correlation with the age of the patient and the clinical diagnosis at onset. TCD appears to be very useful for evaluation of patients with moyamoya disease.