肌萎缩侧索硬化症90例胸锁乳突肌肌电图的特点

The value of EMG study of sternocleidomastoid muscle in diagnosis of amyotrophic lateral sclerosis

目的 探讨胸锁乳突肌肌电图 (EMG)检测在肌萎缩侧索硬化症 (ALS)诊断中的价值。方法 对ALS患者均进行常规EMG检测 ,包括上肢、下肢及胸锁乳突肌 ,测定自发电位 ,募集相 ,运动单位电位的时限、波幅及多相波。比较有、无球部症状的患者之间胸锁乳突肌EMG改变的差异 ,以及不同部位即球部、颈部及腰骶部之间EMG检测结果的差异。结果 有球部症状的患者胸锁乳突肌EMG病变程度重于无球部症状者 (时限增宽幅度分别为 60 6 %± 2 1 2 %和 50 0 %± 1 9 2 % ,P <0 0 5)。胸锁乳突肌EMG自发电位、募集相、运动单位电位时限和波幅改变的程度均不同于上肢和下肢 ,存在显著性差异。结论 胸锁乳突肌EMG检测的异常与球部症状相关 ,而与肢体无关 。

Objective To determine if the EMG changes of sternocleidomastoid muscle are relevant to the bulbar palsy and helpful in the assessment of subclinical bulbar involvement, and elucidate the value of EMG study of sternocleidomastoid muscle in the diagnosis of amyotrophic lateral sclerosis Methods Standard EMG was recorded from at least three limbs (one side abductor pollicis brevis muscle and two sides tibialis anterior muscle) and one side sternocleidomastoid muscle of 40 ALS patients with clinical bulbar signs and 50 ALS patients without clinical bulbar signs Parameters studied included spontaneous activity, duration, amplitude and percentage of polyphasic wave of motor unit potential (MUP); pattern of recruitment EMG parameters of sternocleidomastoid muscle were compared between patients with and without bulbar palsy; the differences of EMG changes among sternocleidomastoid muscle, upper limbs and lower limbs were also analyzed Results EMG analysis of sternocleidomastoid muscle showed neuropathic changes in all 90 ALS patients, the increase of MUP duration was ranged from -8%～104%,mean 54 7%±20 3%; the increase of MUP amplitude was ranged from -20%～270%; spontaneous activity was only found in 3 cases; decreased recruitment was found in 20 cases (22 2%), and the increase of MUP duration and pattern of recruitment were significantly different between patients with and without bulbar palsy ( P <0 05) The increase of MUP duration and amplitude, spontaneous activity and pattern of recruitment were significantly different between sternocleidomastoid muscle and limbs; while there was no difference between upper and lower limbs in spontaneous activity, pattern of recruitment and the increase of MUP duration If the EMG neuropathic changes of sternocleidomastoid muscle were attributed to bulbar part but not upper limb, the number of patients diagnosed as definite and probable ALS was increased significantly in ALS patients without clinical bulbar signs ( P <0 05) Conclusion The EMG neuropathic changes of sternocleidomastoid muscle is related with the symptoms of bulbar part but not cervical part and should be regarded as an evidence of lower motor neuron involved in bulbar part