Intra-axonal corpora amylacea in the CNS.

The distribution of intra-axonal corpora amylacea (IACA) in the CNS was studied in 2 cases of ALS, a hepatic encephalopathy and a Shy-Drager syndrome. A total of 149 IACAs were found. IACAs were observed far most frequently in the gracile nuclei, followed by the anterior horns of the spinal cord and in descending order; lateral geniculate bodies, reticular formation, sensory and motor nuclei in the brain stem, cerebellum and cerebral cortex. The basal ganglia, including the thalamus, contained only a few. IACA were not observed in the pyramidal tracts or in the spinal roots. About 3% of the IACA were sectioned longitudinally, together with the original small nerve fibres and abrupt enlargement of the axons due to the deposits was well demonstrated.