Vascular dementia (VAD) is cognitive impairment caused by changes in t
he blood circulation of the brain. It is not synonymous with multi-inf
arct dementia. The latter is a subgroup of VAD. Neurochemical investig
ations of noninfarcted brain tissue from patients with VAD show genera
l changes in VAD brains. The serotonin metabolism is severely reduced
and so is the activity of choline acetyltransferase. Monamine oxidase
B is significantly increased in the white matter. A severe decrease in
myelin components indicates white matter disturbances of such a degre
e that they must be considered to be of pathogenetic importance. The l
evels of some neuropeptides in the hypothalamus are increased. This is
a finding which is in agreement with clinical findings of a high acti
vity in the hypothalamic-pituitary-adrenal axis in patients with VAD.
This high activity is possibly due to a loss of serotonergic inhibitor
y tone on the hypothalamus in VAD brains.