MORPHOMETRIC STUDY OF THE NEURONS IN THE MEDIAL MAMMILLARY NUCLEUS INACUTE AND CHRONIC WERNICKES ENCEPHALOPATHY

A morphometric study was made of the neurons in the medial mammillary nucleus from 25 cases of Wernicke's encephalopathy (WE) and from 15 ot her cases (control group) in which hepatic or brain disease was exclud ed and the risk factors associated with WE: were not present. The whol e area of the mammillary body was also measured in all cases from both groups. The cases of WE were divided into acute and chronic. A highly significant reduction in the area of the mammillary body was noted in the chronic WE group, when compared to the control and acute WE cases . Although no significant differences were detected between the three groups with regard to the total number of neurons of medial mammillary nucleus, cell density was significantly higher in the chronic WE grou p, when compared to the control and acute WE cases. A significant redu ction was noted in the nuclear volume of the neurons in the chronic ca ses of WE, when compared to the acute WE cases. The positive correlati on between the area of the mammillary body and the nuclear volume of t he neurons in the medial mammillary nucleus was highly significant for the WE group and significant for the control and chronic WE groups. T he reduction in the size of the mammillary bodies associated with pres ervation of the neuronal population, higher cell density and reduction in the size and nuclear volume of the nerve cells in the medial mammi llary nucleus, observed in the chronic cases of WE, may reflect loss o f neuronal processes (neuropil) as the primary lesion in WE and sugges ts that spongiosis, one of the characteristic changes in this disease, may reflect the loss of neuropil in the mammillary bodies.