[Delayed symptoms of hypoxic brain damage after temporary improvement].

A shipyard worker was doing welding work inside a pipe with argon as cover gas. After taking a break he fainted while controlling the weld, also inside the pipe. He was rescued after 15-20 minutes and regained consciousness after a few hours. Two days later he was discharged from hospital in apparently good health. After a week he returned to the hospital suffering from confusion, failing memory, aphasia, apraxia and urinary incontinence. MR showed elevated signal intensity bilaterally in the caudate nucleus. He improved gradually and six months later was given less demanding work. The course of his illness is consistent with delayed neuropsychiatric sequelae after hypoxia, probably due to displacement of oxygen by argon. Delayed symptoms are caused by demyelination in the subcortical white matter.