A clinical, pneumoencephalographic and radioisotopic study of normal-pressure communicating hydrocephalus.

Human serum albumin labelled with iodine-133 or technetium-99(m) was injected by the lumbar or cisternal route into patients suspected of having communicating hydrocephalus, and scintigrams were performed up to 24 hours after injection.The CSF isotope studies were shown to be a valuable adjunct to clinical examination and pneumoencephalography in the diagnosis of hydrocephalus. This was especially true in suspected cases of "normal"-pressure hydrocephalus where there may be considerable uncertainty as to which patients with normal pressure and enlarged ventricles will benefit from a shunting procedure. The CSF isotope study provides useful information to the clinician in differentiating patients with symptomatic hydrocephalus from the larger group with dementia, cerebral atrophy and hydrocephalus ex vacuo.