The effects of increased intracranial pressure on cerebral circulatory functions in man.

The effect of increased intracranial pressure on cerebral blood flow has been the object of very few clinical studies. In accordance with the MonroeKellie-Cushing Doctrine, it would be presumed that increased intracranial pressure would increase cerebrovascular resistance and thereby decrease cerebral blood flow. However, Williams and Lennox (1) in 1939 concluded on the basis of cerebral arteriovenous oxygen differences that cerebral blood flow was practically unaffected by a rise in cerebrospinal fluid pressure. Courtice (2) also working with humans and using a similar technique came to a different conclusion: that there was a slowing of blood flow through the brain in certain types of brain tumor associated with increased intracranial pressure. More recently Ferris (3), using a plethysmographic meas-