Cerebrovascular effects of cerebrospinal fluid removal.

The effects on cerebral blood flow of withdrawal of graded volumes of cerebrospinal fluid (CSF) from the cisterna magna were studied in 12 barbiturate-anaesthetized baboons. The results show that withdrawal of CSF was accompanied by a decreased CSF pressure, an increased CSF PCO2, a decreased CSF PO2 and an increased cerebral blood flow. The possible clinical significance of these findings is pointed out.