THE CANADIAN JOURNAL OF NEUROLOGICAL SCIENCES Lewy Body Dementia Without Alzheimer Changes

Three patients with clinical Alzheimer's disease were found at postmortem examination to have Lewy-bodies and Lewy-like bodies in the cerebral cortex and the pigmented brainstem nuclei. Neuritic plaques were found in neocortical areas but no neurofibrillary tangles. The distribution of cortical neuronal inclusions correlated with the proposed projection of dopamine terminals. Neuronal cell loss was marked in the ventral tegmental area (paranigral nucleus) and the basal nucleus of Meynert, suggesting a defect in dopaminergic and cholinergic innervation of the cerebral cortex. Immunohistochemical investigations revealed positive staining of cortical Lewyand Lewy-like bodies for monoclonal antibodies to phosphorylated neurofilaments (03-44, 06-17, 04-7). Also cerebral neurons containing no inclusions showed positivity, suggesting an early neurofilament abnormality, preceding the formation of Lewy-type inclusions. RESUME: La demence a corps de Lewy en l'absence des changements de type Alzheimer. Des corps de Lewy et des structures similaires aux corps de Lewy ont ete retrouves dans le cortex cerebral et les noyaux pigmentes du tronc cerebral a 1'autopsie de trois patients presentant un tableau clinique de maladie d'Alzheimer. Des plaques nevritiques ont ete trouvees dans les regions corticales, mais pas d'enchevetrements neurofibrillaires. II y avait correlation entre la distribution des inclusions neuronales au niveau du cortex et la projection proposee pour les terminaisons dopaminergiques. La perte cellulaire neuronale etait importante au niveau de la region de la decussation ventrale (noyau paranigral) et du noyau basal de Meynert, suggerant un defaut de I'innervation dopaminergique et cholinergique du cortex cerebral. Des etudes immunohistochimiques ont montre une reaction positive des corps de Lewy et des structures similaires aux corps de Lewy du cortex aux anticorps monoclonaux diriges contre des neurofilaments phosphoryles (03-44,06-17,04-7). Des neurones cerebraux nu contenant pas d'inclusion manifestaient egalement une reaction positive, suggerant une anomalie neurofilamentaire precoce, precedant la formation des inclusions du type des corps de Lewy. Can. J. Neurol. Sri. 1986; 13:490-497 Lewy bodies are abnormal perikaryal inclusions of the human brain and of unknown etiology. They are the histopathologic hallmark of Parkinson's disease with predilection sites in the substantia nigra, locus ceruleus and substantia innominata. They are found rarely in the cerebral cortex, but have been reported in association with changes of Alzheimer's disease,'" Pick's disease, idiopathic Parkinson's disease without dementia," and in neuroaxonal dystrophies." Ultrastructurally, Lewy bodies are composed of an array of filamentous structures radiating from a dense central core. Cerebral Lewy bodies or Lewy-like bodies show a conglomerate of less well organized filaments, and the latter lack the central dense core. Positive immunoreactivity of Lewy bodies with polyclonal and monoclonal antibodies to neurofilaments indicates the presence of neurofilament antigens in these inclusions.'' In the present report we describe the quantitative, morphologic and immunohistochemical findings of cortical Lewy bodies and Lewy-like bodies, as well as the results of cell counts of subcortical projection systems in three cases of Lewy body dementia unassociated with Alzheimer's disease.