[Autonomic nervous functions in Alzheimer type and multi-infarct dementia--a hemodynamic study].

As it has been recently postulated that patients with dementia have some altered neural transmission, these patients are speculated to accompany autonomic dysfunctions. The present study was aimed at investigating autonomic nervous functions in dementia of Alzheimer type (DAT) and multi-infarct dementia (MID). Hemodynamic autonomic functional tests were carried out on 14 patients with DAT (66.9 +/- 11.4 YO; mean +/- SD) and 9 patients with MID (73.1 +/- 7.5) and 16 age-matched healthy volunteers as controls. Blood pressure, pulse rate and respiration were continuously measured. The degree of reflex bradycardia in Aschner's test, a parameter for parasympathetic functions, was significantly lower in MID than in DAT and in the healthy volunteers (p less than 0.01, p less than 0.05, respectively), but there was no significant difference between DAT and the healthy volunteers in this reaction. The degree of reflex hypertension in cold pressor test, a parameter for sympathetic functions, was not significantly different among 3 groups. The degree of orthostatic hypotension also failed to show any significant difference among the groups. From the above data, it is suggested that the patients with DAT have preserved autonomic nervous functions, but that the patients with MID have impaired parasympathetic and normal sympathetic nervous functions.