Patterns of neuronal loss in the cerebral cortex in chronic alcoholic patients.

A loss of neurones from the frontal cortex of chronic alcoholic patients has recently been documented. In addition to this loss of neurones there was found to be a reduction in the mean size of the neuronal soma in both the superior frontal and motor cortices. This could be explained on the basis of a selective loss of larger neurones rather than a general shrinkage of all neurones. This population of large neurones (greater than 90 microns 2) has been recognised as being more vulnerable in both Alzheimer's disease and the normal ageing process. Neurones in 2 size categories (41-90 microns 2 and greater than 90 microns 2) were counted in the superior frontal and motor cortices of age- and sex-matched controls and alcoholics. There was found to be a significant reduction in the number of large neurones in the superior frontal cortex, whilst no change in number was seen in the motor cortex. The possibility that neurones in particular layers of the cortex are more severely affected in alcohol abuse was also considered. The cortex was divided into 3 layers and the number of neurones and glia in each determined. No pattern of regional neuronal loss could be distinguished.