On the association of excess glycogen granules and polyglucosan bodies (corpora amylacea) in astrocytes of a 17-year-old patient with a neurologic disease of unknown origin: clinical, biochemical, and ultrastructural observations.

The case of a 17-year-old patient with a severe progressive neurologic disease is presented. Enzymatic studies revealed that total activity of both hexosaminidases A and B against the synthetic substrate was markedly reduced and that hexosaminidase B activity, studied by heat inactivation and isoelectric focusing, was even more reduced. Rectum and skin biopsies studied by electron microscopy were non-contributory. Brain biopsy was histologically normal. With electron microscopy many filamentous bodies were observed mainly in astrocytic processes; they were interpretable as intra-astrocytic polyglucosan bodies (the corpora amylacea variety of polyglucosan bodies). In addition, an excess of non-membrane-bound glycogen particles, mostly within astrocytes, was also present. Some degree of gliosis was noticed, as well as thickening and redundancy of the basement membrane of capillary vessels. The case is discussed and compared with the conditions described in the literature where either accumulation of glycogen or formation of polyglucosan bodies (corpora amylacea, Lafora-like bodies, Lafora bodies, Bielschowsky bodies, amylopectin bodies), or both occur. Since none of them, however, adequately fit the present case, it must remain undiagnosed.