[Toxic polyneuropathies]

Toxic factors may have damaging effects on the peripheral nerves at different sites: on the axon, on the myelin sheath, on the cell bodies and on the vasa nervorum. The toxic neuropathies can be divided up into polyneuropathies induced by drugs, by industrial, environmental and stimulant poisons. Mostly symmetrical sensory symptoms and signs are the first disturbances, often followed by symmetrical motor pareses. Some polyneuropathies induced by amiodarone, benzene, lead, cimetidine, chloroquine, dapsone, gentamycin, gold, imipramine, hexacarbons, nialamide, penicillin, triorthocresylphosphate and vincristine are primarily dominated by motory losses. Polyneuropathies induced by amitriptyline, ethylene, oxide, lead, chlorprothixene, heroin, hydralazine, methaqualone, nialamide and penicillin show an asymmetrical distribution pattern of the neural losses. In some types of toxic polyneuropathies the cranial nerves and the autonomic nerves are particularly involved. The clinical symptomatology of the most important types of toxic neuropathies are described shortly. The best therapy is, of course, termination of exposure to the toxic substance concerned.