Enzyme defect leads to deposition of polyglucosans
near their site of synthesis in the agranular endoplasmic reticulum. Lafora
bodies are found within the eccrine sweat gland ducts on skin biopsy. They
are periodic acid-Schiff (PAS)-positive inclusions. In biopsy performed in
the central nervous system, Lafora bodies are typically found in the
substantia nigra, superior olive, dentate nucleus, globus pallidus, and
sensorimotor cortex. Intracellular Lafora bodies suggest amyloid in brain,
heart, and liver.