Adult polyglucosan body myopathy with subclinical peripheral neuropathy: case report and review of diseases associated with polyglucosan body accumulation.

A 65-year-old female had polyglucosan body myopathy, usually called "polysaccharide storage myopathy" that presented with increasing distal paresis and only slight weakness of the proximal limb girdle musculature. Muscle biopsy revealed dystrophic changes that could have been mistaken for muscular dystrophy, and the characteristic light as well as electron microscopic features of polyglucosan bodies varying in number at the three sites of muscle biopsies studied (deltoid, quadriceps femoris, and anterior tibial muscle). In addition, there were occasional nonspecific paracristalline mitochondrial inclusions. No abnormal polyglucosan deposits were found in the sural nerve biopsy. Morphometric evaluation of nerve fiber cross sectional areas revealed some degree of demyelination and remyelination, and of nerve fiber degeneration and regeneration. Unlike a series of 10 unselected control sural nerves with Renaut bodies, hypomyelinated nerve fibers were more numerous adjacent to Renaut bodies. This is the first case of polyglucosan body myopathy in which the axon/myelin ratio and the axonal circularity factor in the sural nerve is evaluated and in which a definite lack of polyglucosan bodies or other abnormal glycogen storage products in a peripheral nerve is documented.