Adult-onset rapidly progressive spinal muscular atrophy of shoulder girdle with gammopathy.

The paper reports on clinical and pathologic findings in a 51-year-old man who presented with rapidly progressive spinal muscular atrophy associated with relatively early respiratory paralysis. Clinical diagnosis was based on typical EMG, and bioptic and enzyme findings. In the CSF protein and cell content were normal, the IgG concentration was high, the IgG/Alb quotient increased, intrathecal synthesis of IgG was evident, and oligoclonal gammopathy was found. All of these findings generally appear in neuroallergic diseases. Total loss of anterior-horn cells, demyelination of fasciculus cuneatus and spinothalamic pathways, as well as round Lafora-body like inclusions, preponderantly in the white matter, were observed with light microscopy. Electron microscopic examination revealed reoviruses in the glia cells of the damaged motor zone.