CSF monoamine metabolites in child and adult psychiatric patients. A developmental perspective.

Concentrations of acid metabolites of dopamine and serotonin were measured in lumbar CSF of a diagnostically heterogeneous group of 154 psychiatric patients following oral probenecid loading. The patients ranged in age from 2 to 67 years old. No patients had received psychoactive medications for at least two weeks prior to the lumbar puncture. Children had higher mean CSF homovenillic acid (HVA) levels, higher mean CSF HVA-probenecid ratios, higher CSF HVA-log probenecid ratios, and lower mean CSF probenecid levels than adults. Age was negatively correlated with CSF HVA level and with CSF HVA-probenecid ratio. These correlations were more pronounced in male patients than in female patients.

Confirmation of the amyloidogenic process in posterior cortical atrophy: value of the Aß42/Aß40 ratio.

Posterior cortical atrophy (PCA) is characterized by progressive higher-order visuo-perceptual dysfunction and praxis declines. This syndrome is related to several underlying diseases, including Alzheimer's disease (AD), sometimes involving an amyloidogenic process. The aims of the study were to 1) define cerebrospinal fluid (CSF) biomarker profiles in PCA patients compared to AD patients and 2) explore the amyloidogenic process through the Aß(42)/Aß(40) ratio in PCA patients to elucidate the underlying disease in vivo. CSF biomarker analysis (t-tau, p-tau, Aß(42), and Aß(42)/Aß(40) ratio) and neuropsychological examination were performed in 22 PCA patients and compared with those of age-matched AD patients. Associated clinical neurological signs were investigated (e.g., extrapyramidal motor signs, myoclonus). CSF biomarker profiles did not differ significantly between the PCA and AD groups; 82% of patients with PCA fulfilled the biological criteria for typical AD with abnormal levels of the three markers and 18% of PCA patients presented atypical CSF profiles. All PCA patients with associated clinical neurological signs presented typical AD CSF profiles. The clinical presentations of these patients were similar to other PCA subjects. The Aß(42)/Aß(40) ratio for all PCA patients, including those with atypical CSF profiles, was decreased. Most PCA syndromes were associated with CSF biomarkers suggestive of AD, even in cases with associated clinical neurological signs. The amyloidogenic process was confirmed by the decreased Aß(42)/Aß(40) ratio for all patients. This analysis avoids misdiagnosis in the presence of physiologically high or low amyloid peptide production rates and provides information in vivo to improve understanding of the underlying disease in PCA.