Ultrastructure of Nerve and Muscle Fibers Following Organophosphate Poisoning

This study indicates the ultrastructural changes of sural nerve and gastrocnemius muscle biopsies of a patient poisoned as a result of organophosphate (Tamaron) intake for suicide attempt. Studying the micro-morphology relative decrease of axon diameter which was a result of excessive thickening of the myelin sheaths, and spiral invagination deep into the axon was apparent especially in thick axons was observed. The regular concentric layers of the myelin sheath were destroyed. There was a consistent increase in nuclear heterochromatin, accumulation of glycogen, irregular vacuolization and membranous structures in cytoplasm of Schwann cells. Disarrangement of Sarcomer and myofibrils was apparent in severe degenerated areas. In some micrographs, intact and degenerated areas were coexistent. Extremely thickened capillary basal lamina was remarkable where there was disorganization of muscle fibers. It is concluded that the muscle degeneration in organophosphate poisoning can not be attributed solely to the axonal degeneration but also to the direct toxic effect of the compound.