Accumulation of tubular structures in oligodendroglial and neuronal cells as the basic alteration in multiple system atrophy.

In 8 brains of patients with various combinations of striatonigral degeneration, olivopontocerebellar atrophy and Shy-Drager syndrome, inclusion bodies were demonstrated in the cytoplasm and nucleus of both neuronal and oligodendroglial cells and in neuronal processes by means of silver staining, immunocytochemistry and electron microscopy. Differing from oligodendroglial cytoplasmic inclusions recognized by anti-ubiquitin, anti-alpha- and anti-beta-tubulin, and anti-tau antibodies, neuronal cytoplasmic inclusions were stained only by anti-ubiquitin antibody but not with those raised against cytoskeletal proteins. Tubular structures forming the inclusion bodies irrespective of their glial or neuronal location, have fuzzy cover and side extensions which make them similar to the linear structures described in motor neuron diseases. Our study proves that the accumulation of abnormal tubular structures in both oligodendrocytes and neurons is the basic pathological alteration in multiple system atrophy and defines multiple system atrophy as a group of diseases with similar cellular pathology or as a nosological entity.