患者，女，68岁。1997年7月12日入院，入院前两个半月无明显诱因职四肢麻木力弱，均从四肢远泪向近纸逐渐进展，是对称性、进行住加重，渐出现进会差、消＊明显，无呼吸困难，无发热、咳嗽、咯获。既往无重金属及化学药品接触史，无糖尿病史，不饮酒，吸烟史四十余年，每日约20 The patient, female, is 68 years old. He was admitted to the hospital on July 12, 1997. He had no significant incentives for numbness in the four limbs before admission, progressed from the tears in his extremities to the paper, and it was symmetrical, heavier, and gradually worsened. No breathing difficulties, no fever, cough, and convulsions. No history of exposure to heavy metals and chemicals, no history of diabetes, no alcohol, smoking history for more than 40 years, approximately 20 daily