NEUROPEPTIDES IN CEREBROSPINAL-FLUID OF PATIENTS WITH ALZHEIMERS-DISEASE AND DEMENTIA WITH FRONTOTEMPORAL LOBE DEGENERATION

The two major primary degenerative dementias, dementia of Alzheimer ty pe (DAT) and frontal lobe degeneration of non-Alzheimer type (FLD) hav e several clinical features in common but also many symptoms that diff er. In a clinical material of 80 patients with either of the two forms of dementia (DAT = 39, FLD = 41) we have studied the levels of neurop eptides in the cerebrospinal fluid (CSF) in order to find biochemical markers for CNS affection. The dementia forms were evaluated by carefu l clinical analysis, psychometric testing and measurement of regional cerebral blood flow. Approximately one third of the subjects died duri ng the completion of the study and neuropathology was performed, confi rming the diagnoses. We observed reductions in the CSF levels of antid iuretic hormone and somatostatin in both DAT and FLD. A strong tendenc y to reduction was noted for neuropeptide Y (NPY). There was a correla tion with the duration of disease demonstrating a significant reductio n in NPY levels in subjects with DAT. Most notably there was a strong reduction in the levels of delta sleep inducing peptide (DSIP) in DAT cases only. The levels of DSIP in FLD were the same as in controls. Th e reverse was found for corticotropin releasing factor (CRF) which had a significant reduction in FLD patients but not in those with DAT. Th e present study indicates a difference in the CSF levels of neuropepti des, observations that these may serve as biochemical markers which di fferentiate DAT and FLD.