Investigation of cerebrospinal fluid neuropeptides in idiopathic senile dementia.

Thyrotrophin-releasing hormone and gonadotrophin-releasing hormone were measured in lumbar CSF from patients with idiopathic senile dementia, cerebral tumours and spinal disc lesions. Somatostatin was also measured in lumbar CSF from patients with dementia and patients with other neurological disorders, but the numbers involved were much smaller. The levels of these neuropeptides were significantly reduced in the patients with senile dementia. These results suggest a possible involvement of hpothalamic neuropeptides in idiopathic senile dementia.