Distal spinal muscular atrophy and ophthalmoparesis. A case with selective type 2 fiber hypotrophy

A patient had distal muscular atrophy involving the upper and lower extremities, ptosis of the lid, and ophthalmoparesis and cataracts. Muscle histochemistry and electromyographic examination showed lower motor neuron involvement. This case is similar to others described in the literature and designated as distal spinal muscular atrophy. The unique association with ophthalmologic signs can be considered either as a variant form of the disease or as a separate entity. Muscle biopsy showed selective type 2 muscle fiber hypotrophy in the biceps. A second biopsy specimen of the quadriceps showed type grouping with persistence of small type 2 fibers, suggesting that reinnervation capability is independent of neuronal trophic influence.