[Long- and short-term changes in engorgement in the cerebral vessels under rhythmic photic stimulation]

In 50 patients with cerebrovascular pathology, the EEG and REG were simultaneously recorded during an increase in the cerebral blood volume in response to rhythmic photostimulation. General, local, and short-term reactions of increased cerebral blood volume could be distinguished. The relationship between the EEG changes and cerebral blood volume was most obvious during the short-term reactions: EEG-desynchronization was always followed by increased blood volume. This suggests a possible neurogenic element in vascular reactions. Cerebrovascular pathology was concluded to affect both the neurogenic and the metabolic components of the regulatory mechanism of local circulation.