Adult polyglucosan body disease (APBD) is a rare, chronically progressive, metabolic disorder with severe neurological expression. It is caused by the abnormal accumulation of microscopic material (polyglucosan bodies), predominantly within the myelinated nerve fibers (motor neurons). The polyglucosan bodies are spherical and composed of large, complex, sugar-based molecules (branched polysaccharides).
Symptoms usually begin during middle age or later and usually include muscle weakness, loss of sensation, and/or wasting of muscles (atrophy) in the arms and/or legs. Impaired bladder control (neurogenic bladder) and/or mental confusion (dementia) also occur.