[Carbon monoxide poisoning: clinical features of the victims of the explosion accident of Mitsui-Miike Mikawa coal mine 50 years ago].

Clinical features of carbon monoxide poisoning have been described in 24 victims of an intense explosion accident of the Mitsui-Miike Mikawa coal mine in Japan 50 years ago; these victims were admitted to the Kyushu University Hospital as they suffered from severe poisoning. In the early stage of poisoning, all victims showed disturbed state of consciousness, varying in duration from 5.5 hours to 3 months, and the duration of unconsciousness was closely correlated to the clinical severity in the late stage. Some of the severely poisoned patients showed a transient stage of apallic syndrome. After recovery from unconsciousness, all patients presented with severe amnestic syndrome and loss of initiative. Neurologically, the extrapyramidal signs were prominent in the early stage, which gradually improved in the late stage. Variable types of agnosia and apraxia were apparent in some of the severely and moderately poisoned patients in the late stage, with prominent Gerstmann syndrome and visual-visuospatial agnosias. Since these signs showed poor improvement, the agnosia and apraxia, as well as impaired intellectual ability, remained as a sequela of the poisoning, and were one of the major causes of deficits of the patients in their daily life activities in the late stage.