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Washington University Experience | NEURODEGENERATION | Polyglucosan Body Disease (PGBD) | 8A0 Case 8 History
Case 8 (Bilbao & Schmidt, 2015) ---- Adult Polyglucosan Body Disease (APBD) ---- Our experience suggests that one or two polyglucosan bodies seen in a multifascicular nerve biopsy specimen are a nonspecific finding with no diagnostic implications and increases with age. We have noted polyglucosan bodies in 2-3% of sural nerve biopsies and others have reported a frequency of 8-15%. Observation of more than one PGB per nerve fascicle, of a PGB outside an axon, or of unusually large PGBs (>30 μm) should, however, lead to consideration of APGBD, type IV glycogenosis and (particularly a single PGB in a child <5) in Lafora disease Family history is positive in about one third of cases of APBM, in a pattern suggestive of autosomal recessive inheritance. Polyglucosan bodies are found throughout the central and peripheral nervous system, as well as in myocardium and other non-neural tissues. A nerve biopsy or axillary skin biopsy may be a reliable and less invasive procedure, showing large numbers of PGBs in the myoepithelial cells of apocrine glands. Nerve biopsies reported in APGBD have shown from one to many polyglucosan bodies per nerve fascicle cross-section. Typically the bodies are intra-axonal, round, and range from 5 to 70 μm in diameter. The inclusions are seen in myelinated axons, and less frequently, in unmyelinated axons or Schwann cells. Whether the polyglucosan bodies, when massive in size or present in large numbers, cause the neuropathy, or are an epiphenomenon of the metabolic defect that underlies the neuropathy, remains unknown.
