连枷臂综合征:表现为上肢无力和萎缩的良性运动神经元病

目的回顾总结3例连枷臂综合征患者的临床、电生理和骨骼肌病理改变的特点,并分析此类患者的护理策略。方法与结果3例患者均为男性,发病年龄分别为54岁、71岁和64岁,病程2～4年。主要表现为缓慢、进行性发展的双上肢肌无力和肌肉萎缩,例1和例3均于病程发展后期出现双下肢轻度无力;例2以认知功能障碍发病;例3于疾病后期出现认知功能障碍。3例神经系统检查均呈现双上肢明显肌无力,近端和远端广泛分布的肌肉萎缩,伴随肌张力下降和腱反射减退。例2和例3还同时合并下肢上运动神经元损害及认知功能障碍。对3例患者进行电生理学及病理检查显示:(1)肌电图呈静息状态下的肌纤维颤动和肌束颤动电位,胸锁乳突肌、上肢和下肢肌肉轻收缩时运动单位电位时限增宽、波幅增高或为宽大运动单位电位,重收缩时呈单纯相或混合相。例1双侧尺神经运动神经传导未发现传导阻滞现象。3例感觉和运动神经传导速度于正常值范围,诱发电位波幅有不同程度下降。(2)骨骼肌病理检查可见小角状萎缩肌纤维呈簇分布并累及Ⅰ型和Ⅱ型,伴随明显的肌纤维肥大;有肌纤维核内移现象,还原型辅酶Ⅰ四氮唑还原酶染色偶见靶样纤维,非特异性酯酶染色显示部分萎缩的肌纤维深染。结论3例患者的临床症状、体征及病变分布均符合连枷臂综合征的诊断,以双上肢的局限性损害为突出表现,同时可合并下肢的轻微损害或亚临床改变,与其他运动神经元病一样可合并认知功能障碍。由于上肢严重病残,应当注意采取相应的保护措施,避免发生意外伤害。

Flail arm syndrome: a benign motor neuron disease manifesting as wasting and weakness of the arms

Objective To review the electrophysiological and pathological changes in 3 cases with flail arm syndrome and discuss the characteristic features and nursing care. Methods and Results Three patients (male) developed flail arm syndrome at 54, 71 and 64 years old, respectively, for 2 to 4 years. The main symptoms were chronic, progressive, severe bilateral arms myasthenia and myoatrophy. Case 1 and case 3 developed mild weakness in both legs at late stage. Cognitive impairment was the early presentation in case 2, while occurred at late stage in case 3. In nervous system examination, all cases presented apparent bilateral upper limbs myasthenia, and extensive myoatrophy at proximal and distal end of the arms, associated with hypomyotonia and extensive tendon hyporeflexia. Case 2 and case 3 also developed upper motor neurons impairment at the lower limbs and cognitive impairment. 1) Electromyography showed nervous changes in sternocleidomastoid muscle and the muscles of both upper and lower limbs which were characterized by electric potentials of fibrillation and fasciculation at rest, increased amplitude and duration of motor unit potentials or large motor unit potentials in mild voluntary contraction, and simple or mixed phase in maximal voluntary contraction. In case 1, motor nerve condaction block was not seen in bilateral ulnar nerves. The velocity of sensory and motor nerve conduction was in normal limit in all the cases, but evoked potential amplitude decreased in different degree. 2) Pathological study of skeletal muscles revealed angular atrophic fibers in grouping distribution with apparent hypertrophic changes, accompanied by muscle fiber nucleus internal migration. Target-like fibers were occasionally seen under NADH staining. Some atrophic fibers were deeply stained in NSE. Conclusion Flail arm syndrome could be diagnosed definitely by the clinical manifestations, physical examination and pathological distribution in these 3 cases. Bilateral arms were affected predominatly with mild impairment or subclinical changes of lower limbs. Flail arm syndrome could also develop cognitive impairment as other motor neuron diseases. The upper limb disability is severe, therefore special care should be given to prevent accidents.