P3-078: Prominent reduction in cerebrospinal fluid homovanillic acid and 5-hydroxyindole acetic acid levels in dementia with Lewy bodies

Abstract

One of the most distinct pathologic features in the brains of dementia with Lewy bodies (DLB) patients is the prominent loss of nigrostriatal dopaminergic neurons similar to that in the brains of Parkinson's disease (PD) patients. CSF levels of homovanillic acid (HVA) and 5-hydroxyindole acetic acid (5-HIAA) are decreased in PD patients. In the present study, we measured the CSF levels of HVA and 5-HIAA in DLB patients and compared with those of Alzheimer's disease (AD) patients. Seventy-six patients with PD (73.9 ± 6.8 years, mean±SD), 22 patients with DLB (76.0 ± 6.5 years, including 6 pathologically confirmed cases), 215 patients with AD (76.9 ± 7.3 years) and 38 normal control subjects (76.8 ± 6.5 years) were examined. After informed consent was obtained, CSF samples were collected from the patients by lumbar puncture. CSF levels of HVA and 5-HIAA were measured by HPLC system equipped with 16 electrochemical sensors (CEAS Model 5500, ESA, Bedford, MA, USA). CSF HVA levels were 15.8 ± 8.1 ng/ml (mean±SD) in the PD group, 8.0 ± 5.2 ng/ml in the DLB group, 22.1±13.3 ng/ml in the AD group and 35.2 ± 15.0 ng/ml in the control group. CSF 5-HIAA levels were 12.5 ± 7.2 ng/ml (mean±SD) in the PD group, 8.1 ± 7.9 ng/ml in the DLB group, 17.6±11.5 ng/ml in the AD group and 30.6 ± 13.9 ng/ml in the control group. CSF levels of HVA and 5HIAA were lower in the DLB, PD and AD groups than those in the control group (p<0.001, ANOVA). CSF levels of HVA and 5HIAA in the DLB and PD groups were much lower than those in the AD group (DLB: p<0.01, PD: p<0.05, ANOVA). We demonstrated a prominent reduction in CSF HVA and 5-HIAA levels in DLB patients. The analysis of CSF HVA and 5HIAA levels may be useful in distinguishing DLB patients from AD patients.