Morishita S, Sakakibara T, Tanaka F, Itou Y
Department of Neurology and Internal Medicine, Chubu Rosai Hospital.
Rinsho Shinkeigaku. 1993 Oct;33(10):1070-4.
A 66-year-old housewife felt mild pains in both her forearms after wringing a floorcloth repeatedly while cleaning. The following day she was unable to extend her fingers, but could dorsiflex both wrists. A diagnosis of bilateral interosseous nerve palsy was made. Laboratory studies revealed severe hypopotassemia due to laxative abuse and mild rhabdomyolysis, but her general condition was almost good except for the nerve palsies. Nerve conduction studies suggested conduction disturbance of the posterior interosseous nerve in both forearms. Needle electromyography showed a myogenic pattern in all limbs and a neurogenic pattern only in the muscles innervated by the posterior interosseous nerve. As the serum potassium was normalized, she recovered rapidly from the palsies after only seven days. Repeated electrophysiological studies showed that the conduction disturbance and myogenic patterns had disappeared, and only the neurogenic pattern remained in the muscles innervated by the posterior interosseous nerve. The damage to the posterior interosseous nerve caused by repeated pronation and supination of the forearms when wringing a floorcloth was probably mild. However, hypokalemic neuromyopathy had probably already decreased the muscle membrane excitability, so severe palsy occurred following mild nerve damage. The correction of hypopotassemia alone achieved a dramatic improvement of the bilateral palsy because muscle excitability was restored. This rare case suggests that aggravation of entrapment neuropathy may occur due to hypokalemic neuromyopathy.
一位66岁的家庭主妇在清洁时反复拧干擦地布后，感到双侧前臂轻度疼痛。第二天，她无法伸展手指，但双侧手腕可背屈。诊断为双侧骨间神经麻痹。实验室检查显示，由于滥用泻药导致严重低钾血症和轻度横纹肌溶解，但除神经麻痹外，她的一般状况几乎良好。神经传导研究提示双侧前臂骨间后神经传导障碍。针极肌电图显示所有肢体均呈肌源性模式，仅在骨间后神经支配的肌肉中呈神经源性模式。随着血清钾恢复正常，她仅在七天后就从麻痹中迅速恢复。重复的电生理研究显示，传导障碍和肌源性模式消失，仅在骨间后神经支配的肌肉中仍存在神经源性模式。拧擦地布时前臂反复旋前和旋后可能对骨间后神经造成了轻度损伤。然而，低钾性神经肌肉病可能已经降低了肌肉膜兴奋性，因此在轻度神经损伤后出现了严重麻痹。仅纠正低钾血症就使双侧麻痹得到显著改善，因为肌肉兴奋性得以恢复。这个罕见病例提示，低钾性神经肌肉病可能会加重卡压性神经病。
