When the lysosomal enzymes necessary in catabolic metabolism of glycogen are deficient, glycogen is stored in the skeletal muscles, heart, and liver. The nervous system is involved in Pompe's disease or glycogenosis type II.

Pompe's disease is caused by acid maltase (a-1-4-glucosidase) deficiency and is inherited as an autosomal recessive trait. The disease affects infants, juveniles, and adults. The infantile form is most severe; the juvenile form is relatively benign, with a protracted course. In the adult form, no neuronal storage occurs.

In infants, the disease manifests soon after birth with progressive muscle weakness and firmness, cardio-myopathy, and macroglossia. Death, usually from cardiac failure, occurs within 1 to 2 years. A myopathic EMG pattern and the presence of discrete cytoplasmic vacuoles in the circulating lymphocytes are helpful diagnostic clues. The neuronal glycogen storage is ubiquitous and particularly prominent in the spinal cord and brain stem. Astrocytes store glycogen in the cerebral hemispheric white matter (Fig. 9.9).

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