Cerebrospinal fluid monoamine markers are decreased in dementia of the Alzheimer type with extrapyramidal features

We measured monoamine metabolites and biopterin in the CSF of 37 patients with dementia of the Alzheimer type (DAT), with or without extrapyramidal signs, and in 14 age-matched healthy controls. Compared with concentrations in DAT and controls, the concentrations of homovanillic acid (HVA) and biopterin were significantly decreased in DAT with extrapyramidal signs (EDAT). CSF 3-methoxy-4-hydroxy-phenethyleneglycol and 5-hydroxyindoleacetic acid did not differ significantly among these groups. Age at onset of dementia was positively correlated with CSF HVA (r = 0.49, p < 0.05). The two dementia groups did not differ significantly in the extent of ventricular dilation as measured by quantitative CT, but EDAT patients had lower Mini-Mental State Examination scores than did DAT patients. When patients were matched for age and dementia severity, CSF HVA and biopterin concentrations remained significantly lower in EDAT than in DAT patients. These results indicate that EDAT patients form a distinct subgroup of DAT with evidence of central monoamine dysfunction.