Neurological syndromes produced by some toxic metals encountered industrially or environmentally.

Toxic metals encountered industrially or environmentally may produce the following syndromes: 1) Peripheral neuropathy: which is mainly sensory in arsenic and entirely motor with inorganic lead, organophosphorus compounds and tallium produce a mixed form of peripheral neuropathy. 2) Encephalopathy: usually with lead poisoning where ataxia and hemiplegia or optic atrophy may occur. 3) Optic neuritis: transient or permanent impairment of vision in arsenic poisoning and blurring of vision followed by field fedects with thallium poisoning. 4) Cerebellar disturbances: in the form of ataxia in organic mercury. 5) Parkinsonism: extrapyramidal signs occurs in manganese poisoning shown as mask face and rigidity of muscles. 6) Mental changes: as acute psychosis in organic lead and erethism in organic mercury.