The heterogeneity of neuropathological changes in amyotrophic lateral sclerosis. A review of own autopsy material.

As an approach to the validation of different pathological findings in ALS, we have reviewed the histopathological slides of 24 cases (12 men, 12 women) of autopsy-confirmed ALS which had been treated in our centre (18 definite, 3 probable and 3 possible ALS). The mean age and survival was 57.1 years and 23.5 months respectively. The slides (from motor cortex, basal ganglia, brain stem and spinal cord) were reviewed with special attention paid to the severity of motor cortex and corticospinal tract degeneration, infiltrations of macrophages, atrophy of lower motor neurones, accumulation of lipofuscin, chromatolysis and gliosis. We also searched for the occurrence of axonal spheroids and various kinds of inclusions, like Bunina bodies, large hyaline, Lewy-body-like inclusions and even larger "hyaline balls", and ubiquitinated inclusions. The histological examination revealed considerable differences between particular cases. Different kinds of inclusions were found in 19 out of 24 cases. A shorter duration of the disease was found in the cases with numerous macrophages. The apparent histological degeneration of the motor cortex was found in cases with longer duration of the disease. However, the differences were not significant and no correlation between the occurrence of any type of inclusion or any other pathological finding and the duration of the disease was found. Whether apparent pathomorphological "heterogeneity" reflects some true differences in the pathogenesis of ALS is disputable.