For patients with moderate to severe gas poisoning, there may be sequelae like delayed encephalopathy symptoms, including mental consciousness disorder, extravertebral mental disorder, etc. The details are as follows: I. Mental consciousness disorder: the patient may have a mental consciousness disorder, presenting a state of dementia, delirium, or de-corticalized state. Extra-vertebral system mental disorder: extra-vertebral system mental disorder may occur, such as tremor paralysis syndrome. Neurological damage of vertebral system: Neurological damage of vertebral system may occur, such as hemiparesis, positive pathological reflexes or urinary incontinence, and focal dysfunction of the cerebral cortex may also occur, such as aphasia, blindness, secondary epilepsy. Peripheral neuritis: Peripheral neuritis may occur, and patients may have skin sensory disorders, sometimes posterior bulbar neuritis or other cerebral nerve palsy. The mechanism is not yet clear. It is generally believed that it is related to the deep interstitium of the brain, including the center of the semiovals, the large demyelination around the ventricles, as well as the ischemia, hypoxia and necrosis of the brain locally, and that factors such as mental trauma during the recovery period, overload of mental or physical strength, etc., which increase the oxygen depletion of the organism, are often the causative factors.