Cerebral ventricular size and cerebrospinal fluid acetylcholinesterase levels in senile dementia of the Alzheimer type.

Computed tomography (CT) was performed in 16 patients with a diagnosis of senile dementia of the Alzheimer type (SDAT). CT scans were rated without knowledge of clinical and laboratory data, and lateral ventricle-brain ratios (VBRs) calculated. Cerebrospinal fluid (CSF) acetylcholinesterase (AChE) activity was measured by radioenzymatic assay in all patients, and degree of dementia quantified using the Mini-Mental State Examination (MMSE). There were significant correlations between cerebral atrophy as assessed by VBR and CSF AChE activity. Cognitive impairment on MMSE also correlated significantly with VBR. These correlations were not accounted for by age, dilutional effects, or duration of illness. The relationship between VBR and AChE activity demonstrates an association between two independently determined pre-mortem measures of illness.