[Transcranial Doppler exercise test in patients with chronic tension headache].

In the etiopathology of tension type headache, vascular and autonomic disorders are discussed. Fifteen patients with chronic tension type headache according to the criteria of the IHS were investigated using the TCD-ergometer-test--a method used to evaluate the myogenic mechanism of cerebrovascular autoregulation--and the results were compared with the findings in fifteen healthy control subjects. The patients' Mean Flow Velocity (TAVmean) and Resistance Index (RI) at rest and after exercise were significantly decreased (p < 0.05). During exercise they normalized. The patients' endtidal pCO2 at rest and during exercise was significantly lower than the corresponding values of the control group (p < 0.05). Regarding blood pressure elevation and heart rate increase during exercise both groups did not differ significantly (p > 0.05). These findings suggest that patients with tension type headache have a diminished vascular tone in the cerebral vessels at rest which is normalised during exercise. The reduced endtidal pCO2 is considered as a physiological response to increase vascular tone via metabolic mechanism of cerebrovascular autoregulation. In conclusion it is suggested that therapeutic procedures which activate sympathetic autonomic nervous function to train cerebral vessels should be more carefully considered.