Fig. 2. Dopplerograms of flow in ACA (a) and MCA (b). There is a picture of arteriovenous anastomosis; linear blood flow velocity is increased in ACA up to 105 cm/s (a normal value of 50 cm/s) and MCA up to 103 cm/s (a normal value of 62 cm/s); pulsation index is reduced up to 0.83. There is reduction of vasomotor reactivity index up to 55% in MCA and 12% in ACA (98-100%) in functional loads.