The aim of this investigation is to study the effect of BTA on the cerebral blood flow in patients with chronic daily headache. The analysis of Doppler ultrasonography and transcranial Dopplergraphy findings has shown the following: after the treatment 34% of the patients had no extravasal effect and in 66% of the patients it became moderate and after the treatment normal venous outflow was found in 58% of the patients . The results of the pilot study demonstrate the effect of BT-A injection on the cerebral blood flow by means of optimizing both the arterial blood flow and the venous outflow from the cavity of the skull.