钾敏感型周期性麻痹一个家系研究

The Study of a Family with Potassium-sensitive Periodic Paralysis

目的 探讨正常血钾型家族性周期性麻痹的临床、病理特点及可行的治疗方法。方法 对一个血钾正常的周期性麻痹患者家系进行临床及病理研究。结果 该家系 4代 1 8名有血缘关系的家庭成员中 ,共有 8名男女成员患病 ,符合常染色体显性遗传方式。受累成员均在 1 0岁前发病 ,表现为发作性四肢无力 ,持续 1～ 2周后逐渐恢复。间歇期基本正常。儿童期发作频繁 ,为每月数次 ,不能上学。青春期后发作减少 ,约每年数次。常见诱因有饥饿、寒冷、兴奋、剧烈运动后休息及进食西瓜等。发作时及发作后血钾均正常。钾负荷试验诱发出典型全身无力发作 ,静脉滴注葡萄糖及胰岛素能迅速缓解。肌电图检查支持周期性麻痹诊断。肌肉活检未发现明显病理学改变。使用已报道的治疗方法均不能有效缓解生活因素诱发的肌无力。结论 血钾正常的钾敏感型周期性麻痹很可能是高钾型周期性麻痹的变异型 ,但与已报道的家系又有诸多不同 ,需进一步研究其分子缺陷及离子通道特性。

Objective The clinical and myopathological characteristics of familial normokalemic periodic paralysis (NormoKPP)and its potential treatment have been reviewed. Methods Eight patients with normoKPP from a family have been studied clinically and myopathologically. Results The normoKPP is transmitted in autosomal dominantpatternaffecting8 malesand females out of 18 consanguine membersinthe 4-generation family. All affected members experience their initial attacks of muscle weakness in their first decade of age. The episodic paralysis usually involving the four extremities resolves over 2 weeks with almost complete recovery between attacks. The attacks occur more frequently and last shorter in childhood, but less frequently and last longer in adults. The weakness is so severe and frequent that the children are unable to continue their learning at school. Theattacksare typicallyprecipitatedbyfasting, cold, restafterstrenuous exercises or eating watermelon. The serum levels of potassium are normal during and after their attacks. Potassium load test provoked a typically paralytic episode that was quickly reversed by intravenous administration of glucose and insulin. In addition, the diagnosis of normoKPP could be confirmed by electrophysiological and myopathological studies. Thereportedtreatmentsfailedtoacceleraterecoveryfromepisodicweakness. Conclusions NormoKPP is probably a variant of hyperkalemic periodic paralysis, but differs from the reported families in many aspects. Further genetic and molecular studies are required to elucidate the genetic/ phenotypic relation.