三重经颅磁刺激技术对肌萎缩侧索硬化上运动神经元损害的评价及其作用

目的 研究三重经颅磁刺激技术(triple stimulation technique,TST)在肌萎缩侧索硬化(amyotrophic lateral sclerosis,ALS)患者上运动神经元(upper motor neuron,UMN)损害的评价和诊断中的作用.方法 收集我院门诊和病房收治的ALS患者50例和健康志愿者22名进行右上肢小指展肌TST测定、中枢运动传导时间(central motor conduction time,CMCT)测定、运动诱发电位(motor evoked potential,MEP)潜伏期、静息运动阈值(resting motor threshold,RMT)、复合肌肉动作电位(compound muscle action potential,CMAP)测定及对TST与改良的Ashworth评分(Modified Ashworth Scale,MAS)、医学研究委员会评分、修订的ALS功能评分、病情进展速度等进行相关性分析.结果 根据EI Escorial的ALS诊断标准,临床确诊5例,临床拟诊19例,实验室辅助拟诊24例,临床可能2例.ALS患者右上肢有UMN体征组28例,62.0%(40.7%,75.9%)]与无UMN体征组22例,95.6%(85.4%,100.0%)],健康对照组(96.9%±2.6%)比较,TST波幅比M50(M25,M75)]差异均有统计学意义(Z=-4.827、-5.435,均P=0.000).有UMN体征组(89.3%)与无UMN体征组(27.3%)、健康对照组(9.1%)TST波幅比异常出现率差异均有统计学意义(χ2=20.109、31.897,均P=0.000),无UMN体征组与健康对照组差异无统计学意义(χ2=1.375,P=0.241).TST波幅比、MEP潜伏期、易化状态下MEP潜伏期、CMCT、RMT对ALS患者UMN体征的阳性检出率分别为89.3%、64.3%、53.6%、64.3%、78.6%.TST波幅比与右上肢腱反射(r=0.690)、MAS评分(r=-0.772)、诊断分级(r=0.483)存在相关性(均P=0.000),与RMT(r=-0.774,P=0.000)、MEP潜伏期(r=-0.444,P=0.005)、MEP/CMAPerb(r=0.685,P=0.000)、易化状态下MEP/CMAPerb(r=0.770,P=0.000)存在相关性.结论 TST为ALS患者UMN损害提供了敏感的检测指标,能够发现临床下UMN受累,较传统经颅磁刺激方法 提高了诊断的敏感性,能够对UMN损害进行半定量评价,提示其有可能成为监测病情变化的客观评价指标.

Assessment of the upper motor neuron lesion in amyotrophic lateral sclerosis with the triple stimulation technique

Objective To quantitatively estimate upper motor neuron (UMN) lesion with the triple stimulation technique (TST) in amyotrophic lateral sclerosis (ALS). Methods Fifty ALS patients and 22 normal controls were enrolled in the study. Patients were examined clinically with conventional transcranial magnetic stimulation (TMS) and TST at abductor digiti minimi. Central motor conduction time (CMCT),motor evoked potential ( MEP), resting motor threshold ( RMT), compound muscle action potential ( CMAP), modified ashworth scale ( MAS), Medical Research Council scale and modified ALS scale were assessed and their correlation to disease progress was analyzed. Results The TST amplitude ratio was significantly decreased in ALS patients with UMN signs(28 cases 62. 0% (40. 7%, 75.9% ) ), compared with controls ( 96. 9% ± 2. 6% ) and ALS patients without UMN signs ( 22 cases 95.6% ( 85.4%,100. 0% ) ;Z = -4. 827, -5.435, both P =0. 000). The abnormal rates of the TST amplitude in ALS with UMN signs, ALS without UMN signs and controls were 89. 3%, 27.3% ,9. 1% respectively. The abnormal rates of the TST amplitude, the latency of MEP, CMCT, RMT in detecting UMN lesions were 89. 3%,64. 3%, 53.6%, 64. 3% , 78. 6%, respectively. The TST amplitude was significantly correlated to tendon reflex in right arm ( r = 0. 690, P = 0. 000), with modified ashworth scale ( MAS, r = - 0. 772,P = 0. 000),with diagnostic degree ( r = 0. 483, P = 0. 000), with RMT ( r = - 0. 774,P = 0. 000), the latency of MEP (r = - 0. 444, P = 0. 005 ), motor evoked potential/compound muscle action potential of erb' s ( MEP/ CMAPerb, r = 0. 685, P = 0. 000 ), MEP/CMAPerb in facilitation ( r = 0. 770, P = 0. 000). Conclusions TST appears to be a more accurate and sensitive measure of detecting and quantifying UMN abnormality in ALS patients than the other parameters. TST may reveal the subclinical UMN impairment in ALS and provide an accurate diagnosis assessment for UMN loss in ALS and an objective scale for monitoring the progression of disease.