DEMENTIA IN 2 HISTOLOGICALLY CONFIRMED CASES OF MULTIPLE-SCLEROSIS - ONE CASE WITH ISOLATED DEMENTIA AND ONE CASE ASSOCIATED WITH PSYCHIATRIC-SYMPTOMS

During the past 10 years, considerable attention has been devoted to c ognitive impairment in multiple sclerosis. Occasionally this impairmen t may be so severe that multiple sclerosis presents as a dementia asso ciated with only minor neurological signs and symptoms. The cases of t wo women affected by multiple sclerosis who presented with a pure deme ntia are reported. In the first patient, a progressive apragmatic beha vioural disturbance with reduced short term memory and learning abilit ies were the main clinical features. Neuropathological examination of the brain disclosed numerous plaques in the periventricular white matt er, with severe atrophy of the corpus callosum. Plaques were also seen in the white matter of both hippocampus and in the columns of the for nix. The impairment of short term memory could be linked to these lesi ons. Behavioural changes were probably related to the bilateral lesion s of the long associative bundles that disconnected the frontal lobes from other parts of the cerebral hemispheres. In the second patient, v isual hallucinations were associated with cognitive dysfunction. MRI s howed large plaques in the white matter of both left frontal and tempo ral lobes. Smaller plaques were also present in the periventricular wh ite matter of the occipital lobes, the nature of which were confirmed by a stereotactic biopsy.