腹直肌肌电图在肌萎缩侧索硬化诊断中的价值

目的建立腹直肌肌电图运动单位动作电位(MUAP)各参数正常参考值,并探讨其在诊断肌萎缩侧索硬化(ALS)中的价值。方法对ALS组67例患者(其中有呼吸困难症状者19例)进行常规肌电图检测,包括上、下肢远近端肌肉、胸锁乳突肌、下胸段脊旁肌及腹直肌,测定自发电位、募集相、MUAP时限、波幅及多相波,其中脊旁肌只检测自发电位和募集相。对健康对照组109名健康志愿者进行腹直肌肌电图的检测。比较ALS组腹直肌肌电图与健康组的差异、ALS组中腹直肌肌电图与下胸段脊旁肌肌电图的差异以及腹直肌肌电图与呼吸障碍症状的关系。结果健康对照组腹直肌肌电图的MUAP参数分别为:波幅(373·78±56·46)μV,时限(9·95±1·13)ms,多相波(19·40±4·52)%;ALS组腹直肌肌电图的MUAP各参数分别为:波幅(537·19±159·04)μV,时限(13·02±1·30)ms,多相波(31·19±8·84)%,ALS组腹直肌肌电图各参数与健康对照组相比差异有统计学意义;ALS组腹直肌肌电图神经源性改变(63/67,94·0%)与下胸段脊旁肌肌电图(57/67,85·1%)的差异无统计学意义;有呼吸困难症状患者的腹直肌肌电图自发电位(18/19,94·7%)多于无呼吸困难症状患者(32/48,66·7%)。结论腹直肌肌电图各参数均能可靠、稳定地测出,可作为检测ALS患者胸段下运动神经元病变的辅助手段。     

胸段脊旁肌肌电图在肌萎缩侧索硬化诊断中的作用

目的 研究胸段脊旁肌自发电位在诊断肌萎缩侧索硬化(amyotrophic lateral sclerosis，ALS)中的价值。方法 50例确诊的ALS患者分别行胸段脊旁肌自发电位、胸锁乳突肌运动单位，部分患者行舌肌自发电位检测；同时，将性别、年龄相匹配的30例根性损害的患者和30名健康人作为对照，行胸段脊旁肌自发电位检测。结果 50例ALS患者中，41例(82％)胸段脊旁肌肌电图可见大量纤颤电位和正锐波；胸锁乳突肌肌电图无一例见自发电位，但有48例(96%)运动单位时限增宽，波幅增高，符合慢性神经源性损害改变；6例患者行舌肌自发电位检测，3例可见自发电位。30例根性病变的患者中，2例(7％)可见胸段脊旁肌有少量自发电位；健康对照组未见胸段脊旁肌自发电位。结论 胸段脊旁肌大量自发电位对诊断ALS具有一定的敏感性。     

肌萎缩侧索硬化症90例胸锁乳突肌肌电图的特点

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 ,其神经源性改变可反映球部下运动神经元病变     

上运动神经元损害为主的肌萎缩侧索硬化患者的临床和神经电生理特点

目的 探讨以上运动神经元损害为主要表现的肌萎缩侧索硬化( UMN-D ALS)的临床和神经电生理特点.方法 回顾分析76例UMN-D ALS患者及19例原发性侧索硬化(PLS)患者,对其临床表现和神经电生理特点进行总结、比较.神经电生理研究主要包括四肢神经传导速度和延髓、颈、胸、腰骶4个区的肌肉肌电图检测,每隔6个月复查1次.结果 8例初诊为PLS的患者随访中出现下运动神经元损害的表现,转入UMN-D ALS组,此组患者增为84例.＞40岁的UMN-D ALS患者中女性更多(男:女=1∶1.37).32例(38.1％)延髓部起病,从首发症状到肌电图提示神经源性改变平均为30个月,77例(91.6％)在病程4年内出现下运动神经元损害的表现.随访4年时,UMN-D ALS组修改版ALS神经功能评分(分)由40±3下降为32±4(t=1.83,P＜0.05);UMN-D ALS组与PLS组第一骨间肌运动单位动作电位波幅、时限相比[(1003.7±25.2) μV和(353.5±21.5) μV,t=2.34,P＜0.05;(19.8±2.3)ms和(9.6±1.3)ms,t=1.85,P＜0.05]差异有统计学意义.结论 UMN-D ALS患者中女性、以延髓部起病患者比例较高,比PLS进展快,肌电图神经源性损害局限.     

肛门括约肌肌电图对多系统萎缩的诊断价值

目的分析肛门括约肌肌电图的改变对多系统萎缩的诊断价值.方法对27例诊断多系统萎缩的患者组和27例非多系统萎缩者为对照组,行肛门括约肌肌电图检查,观察静息时有无自发电位;轻收缩时运动单位的平均时限、平均波幅、多相波百分比、有无卫星电位;大力收缩时的相型和波幅.对2组各参数进行统计分析.结果多系统萎缩患者组25例(92.6%)肛门括约肌肌电图有不同程度的改变,平均时限、平均波幅、多相波百分比、自发电位与对照组比较有显著性差异(P＜0.001).结论肛门括约肌肌电图检查对多系统萎缩的诊断有一定的价值.在怀疑多系统萎缩时该项检查可作为常规的电生理检查方法.     

多系统萎缩患者的尿道括约肌和肛门括约肌肌电图对比分析

目的 比较多系统萎缩(MSA)患者尿道括约肌肌电图(US-EMG)和肛门括约肌肌电图(EAS-EMG)变化特征.方法 对拟诊的9例MSA患者行US-EMG和EAS-EMG测定.分别测定运动单位的平均时限、平均波幅、轻收缩波幅、多相波以及大力收缩募集电位共5组数据,并统计分析组间差异.结果 9例MSA患者US-EMG与EAS-EMG两种检查方法均证实7例患者肌电图结果呈神经源性损伤,两种检查结果中平均波幅[( 1063.44±499.92) μV与(634.89±265.07) μV]、多相波[中位数(四分位数间距),分别为0(0,20％)与57％ (28％,63％)]差异有统计学意义(t=2.567,P=0.033;t =2.833,P=0.012).结论 US-EMG和EAS-EMG在MSA诊断中均具有较特异的诊断价值,虽然US-EMG检查实施有一定技巧性和难度,但其轻收缩波幅等指标的异常对于仅有排尿障碍而无便秘的MSA可能具有更为显著的诊断价值.     

不同阶段肌萎缩侧索硬化患者肌电图的研究

目的研究不同阶段肌萎缩侧索硬化(ALS)患者的定量肌电图(EMG)表现,寻找早期诊断ALS的敏感电生理指标。方法对60例ALS患者进行定量EMG检查,分析不同阶段运动单位动作电位(MUPs)多相参数、自发电位和大力收缩募集相变化,并与健康对照组进行比较。结果不同阶段ALS EMG表现不同,从最早期阶段到最后阶段可分为N0~N56个连续的电生理阶段。N2期MUPs的时限、波幅、面积、运动单位指数(SI)、多相波数值均较健康对照组显著升高(均P<0·001),N0、N4期MUPs部分多相参数数值明显升高(P<0·05);自发电位在病变的各个阶段均可见到,以N2~N5多见,分别为63·6%、83·0%、91·2%、100%。结论ALS患者早期阶段如出现自发电位,即为下运动神经元受累的特征表现;定量EMG检查中运动单位面积和波幅增大是其显著特点。     

健康人膈肌肌电图初探

目的　探索膈肌肌电图的方法及其在健康人的特点。方法　以同心圆针电极用肋间隙进针法分别记录屏气、平静吸气和深吸气时 1 3位健康受试者的 2 2侧膈肌肌电活动。结果　所有受检者均无任何并发症。屏气时未见纤颤电位和正锐波 ;深吸气时见干扰相或混合相 ;平静吸气时膈肌运动单位动作电位各参数不受侧别、性别、年龄、身高、胸围、腹围影响 ;合并侧别和性别后时限 7 9ms± 0 6ms、波幅 3 1 3 μV± 68μV、面积 3 0 6( μV×ms)± 81 ( μV×ms)、多相波出现率的中位数为 1 9%。结论　膈肌针极肌电图是评价与呼吸有关的神经肌肉功能的不可替代的电生理指标 ;用肋间隙进针法检测膈肌针极肌电图比较安全     

多发性肌炎患者神经电生理特点分析

目的增进对多发性肌炎患者肌电图特点的认识,提高其检查的阳性率。方法对91例多发性肌炎患者进行肌电图(EMG)、神经传导速度测定。结果肌电图异常率为87.9%,肌源性损害者占79.1%,神经源性损害者占8.8%。其中插入电位延长、自发电位的阳性率分别为6%和52%,肱二头肌出现率较高,外展拇短肌出现率最低(p<0.05);运动单位电位(MUP)时限缩短的阳性率为71%,胫前肌出现率最高,外展拇短肌最低(p<0.05);MUP波幅降低的阳性率较低,仅为7%;多相波增多的阳性率为29%,胫前肌出现率最高,股四头肌最低(p<0.05);重收缩时波形异常的阳性率为26%,以股四头肌出现率最高;重收缩时峰值电压降低的阳性率为31%,胫前肌出现率最高,外展拇短肌最低(均p<0.05)。5例患者EMG呈神经源性损害,1例感觉神经传导速度减慢,2例运动神经传导速度减慢。肌电图正常组、肌源性损害组及神经源性损害组患者的病程、年龄无明显差异。结论 EMG对多发性肌炎诊断的阳性率为87.9%,其中以MUP时限缩短出现率最高为71%,其次为自发电位为52%。EMG异常最多见于肱二头肌、股四头肌和胫前肌。     

单纤维肌电图在肌萎缩侧索硬化和颈椎病鉴别诊断中的价值

目的 探讨单纤维肌电图(SFEMG)技术在肌萎缩侧索硬化(ALS)与神经根型和脊髓型颈椎病鉴别诊断中的价值.方法 对61例ALS伴有MRI颈椎病表现、59例ALS不伴MRI颈椎病表现、55例神经根型和脊髓型颈椎病患者进行伸指总肌SFEMG测定,分析不同组之间SFEMG改变的特点.结果 在3组患者中,平均颤抖(jitter)值分别为(81.2±25.9)、(91.6±32.4)、(40.9±11.8) μs,jitter>55 μs的百分比M50分别为73%、80%、5%,阻滞所占百分比M50分别为10%、20%、0,纤维密度分别为2.9±0.5、2.9±0.6、2.4±0.6.ALS伴和不伴MRI颈椎病变2组之间各参数比较差异无统计学意义.两组ALS患者合并后[平均jitter值(86.3±29.6)μs,jitter>55μs的百分比M50为80%,阻滞所占百分比M50为14%,纤维密度2.9±0.5]再与颈椎病组比较,各参数均明显高于颈椎病组(分别为t=14.49,Z=8.96、7.68,t=5.83,均P=0.000).在经随诊而确诊的18例ALS患者中,初诊时肌电图仅有1个节段的神经源性损害,在伸指总肌肌力和常规肌电图均正常情况下,有16例SFEMG可见纤维密度增高,13例jitter增宽,6例可见阻滞.结论 ALS伴或不伴MRI颈椎病变的SFEMG均表现为jitter明显增宽,可伴有阻滞,纤维密度增高,与神经根型和(或)脊髓型颈椎病患者明显不同.SFEMG测定有助于ALS与颈椎病的鉴别诊断.     

斜方肌肌电图运动单位动作电位成人正常参考值的建立

目的 探讨不同血清抗体重症肌无力(MG)的临床特征.方法 用荧光免疫沉淀法(FIPA)和荧光免疫细胞染色法(CBA)检测119例MG患者血清乙酰胆碱受体抗体(AChR-Ab)和肌肉特异性受体酪氨酸激酶抗体(MuSK-Ab)水平.比较AChR-Ab阳性、MuSK-Ab阳性、血清抗体阴性MG的临床特征.结果 纳入119例患者中,90例AChR-Ab阳性(75.6%),29例阴性:其中5例MuSK-Ab阳性(17.2%),24例血清抗体阴性(82.8%).AChR-Ab阳性、MuSK-Ab阳性和血清抗体阴性MG 3组比较,男女比例和平均发病年龄差异均无统计学意义.3例MuSK-Ab阳性的患者主要表现为延髓肌受累;79.2%(19/24)的血清抗体阴性MG患者表现为美国MG协会(MGFA)Ⅰ型;2例MuSK-Ab阳性的患者MGFA≥Ⅲ型;MuSK-Ab滴度水平与患者病情严重程度相关(r=0.941,P=0.014);MuSK-Ab阳性的患者均未发现有胸腺的异常.结论 MuSK-Ab仅出现在AChR-Ab阴性患者的血清中.MuSK-Ab阳性的患者主要表现为延髓肌受累,病情较重且不伴有胸腺的病变.MuSK-Ab阳性的MG可能是不同于血清AChR-Ab阳性的MG的又一亚型.     

Clinical utility of trapezius muscle studies in the evaluation of amyotrophic lateral sclerosis.

Needle electromyography (EMG) and determining the motor evoked potential (MEP) of the genioglossus (tongue) are difficult to perform in evaluation of the craniobulbar region in patients with amyotrophic lateral sclerosis (ALS). Needle EMG and MEP determination in the upper trapezius were carried out in 17 consecutive ALS patients. The needle EMG parameters recorded included abnormal spontaneous activity and motor unit action potential morphology. An upper motor neuron lesion was presumed when either response to cortical stimulation was absent, or the central conduction time was delayed (>mean + 2 SD). Of the 12 patients with limb-onset ALS, using needle EMG, 11 were found to have abnormalities in the upper trapezius, and only five in the tongue. Three of the six patients with isolated limb involvement had abnormal MEP findings. In conclusion, electrophysiological studies of the upper trapezius are useful in ALS patients without bulbar symptoms.     

运动神经元病患者胸锁乳突肌肌电图的特征

目的探讨运动神经元病(MND)患者胸锁乳突肌(SCM)肌电图的特征。方法回顾性分析461例MND患者及349例非MND患者的临床和肌电图资料。结果MND组SCM肌电图异常率(60.3%)显著高于非MND组(4.6%)(P<0.01);确诊级MND患者SCM肌电图的异常率(77.4%)明显高于其他诊断级(均P<0.01);MND组中,SCM肌电图的异常率(60.3%)低于上、下肢体肌肉的肌电图(93.2%、84.4%)(均P<0.001);MND患者SCM肌电图异常以自发电位(42.5%)和轻收缩时运动单位电位时限增宽(43.2%)最为常见;MND组有延髓症状者SCM肌电图的异常率(71.7%)明显高于无延髓症状者(54.3%)(P<0.05)。结论MND患者SCM肌电图异常率及其特异性高,为延髓肌受累的指征,有助于MND的诊断与鉴别诊断。     

Electromyography of sternocleidomastoid muscle in ALS: a prospective study

Needle electromyography (EMG) of the tongue is difficult to perform because of frequent uncontrollable movement. We chose the sternocleidomastoid (SCM) muscle as a possible alternative for assessing the involvement of the rostral neuraxis in amyotrophic lateral sclerosis (ALS). We prospectively studied 21 ALS patients during our initial diagnostic evaluation. EMG parameters that we recorded included the presence of abnormal spontaneous activity, pattern of motor unit potential recruitment, and configuration of motor unit action potentials. For the six patients with bulbar-onset ALS, three had abnormalities in the SCM and three had abnormalities in the tongue. In contrast, for the 15 patients with limb-onset ALS, 9 had abnormalities in the SCM, and only 3 had abnormalities in the tongue. Our results demonstrate the utility of needle EMG of the SCM in the evaluation of ALS. EMG of the SCM carries a similar sensitivity as the tongue in ALS patients with bulbar symptoms, but is more sensitive than the tongue in patients without bulbar symptoms. SCM innervation includes the rostral cervical cord and brainstem, and EMG abnormalities in this muscle support a diffuse involvement, which is unique to ALS.     

Amyotrophic lateral sclerosis versus cervical spondylotic myelopathy: a study using transcranial magnetic stimulation with recordings from the trapezius and limb muscles.

OBJECTIVE: We report an electrophysiological method to differentiate amyotrophic lateral sclerosis (ALS) from cervical spondylotic myelopathy (CSM). METHODS: Motor evoked potentials (MEPs) by transcranial magnetic stimulation were investigated in patients with ALS (n=10) and CSM (n=9). In addition to limb MEPs using the triple stimulation technique (TST) at upper limbs, MEPs recorded from trapezius muscles were compared with those obtained from 23 normal subjects. The parameters studied were: central motor conduction time, amplitude ratio and, for the trapezius, the interside asymmetry. RESULTS: Whereas limb MEPs were abnormal in most ALS and CSM patients (17/19), trapezius MEPs were abnormal in all ALS patients, and normal in 8 out of 9 CSM patients. CONCLUSION: Recording of trapezius MEPs is a valuable addition to the limb MEPs study, since it distinguishes ALS from SCM in most patients.     

Needle EMG of the tongue: motor unit action potential versus peak ratio analysis in limb and bulbar onset amyotrophic lateral sclerosis

OBJECTIVES—to find out if conventional andautomatic needle EMG of the tongue can be helpful in the diagnosis anddifferentiation of limb and bulbar onset amyotrophic lateral sclerosis.
METHODS—Motor unit action potential (MUAP)analysis and peak ratio interference pattern analysis were performed inthe right genioglossus muscle of 30 healthy subjects aged 30-81 years,10 patients aged 49-73 years with limb onset amyotrophic lateralsclerosis, and eight patients aged 52-75 years with bulbar onsetamyotrophic lateral sclerosis. Electrical activity was sampled viastandard concentric needle electrodes with a commercially available EMG recorder.
RESULTS—Normal mean (2SD) MUAP duration was 6.6 (1.5) ms. Normal mean (2SD) MUAP amplitude was 224 (97.4) µV. Normalmean (2SD) peak ratio (PR), turns/second (T/s), amplitude/turn (A/T),and time intervals (TI1, TI2, TI3) were 1.68 (0.56), 732 (303.9), 446 (180.3) µV, 2.62 (0.34), 2.31 (0.14), and 1.01 (0.50) respectively.Mean MUAP duration and amplitude were significantly increased in limb onset (P=0.0001 and P=0.013) and bulbar onset amyotrophic lateral sclerosis (P=0.0001 and P=0.017). Peak ratio indices stayed unchanged in limb onset amyotrophic lateral sclerosis but were significantly decreased (PR, T/s, A/T, TI1, and TI2) or increased (TI3) in bulbar onset disease. The sensitivity of the MUAP analysis was 70% in limband 75% in bulbar onset amyotrophic lateral sclerosis. The sensitivityof the peak ratio interference pattern analysis was 20% in limb and100% in bulbar onset amyotrophic lateral sclerosis. Subclinicalinvolvement of the tongue was found in 20% of the patients with limbonset amyotrophic lateral sclerosis and could be more accuratelyassessed with MUAP analysis than with automatic EMG.
CONCLUSIONS—both conventional and automaticneedle EMG of the tongue are valuable electrophysiological devices toassess the clinical and subclinical involvement of the tongue inpatients with limb and bulbar onset amyotrophic lateral sclerosis.

     

Utility of trapezius EMG for diagnosis of amyotrophic lateral sclerosis

Needle electromyography (EMG) of the tongue is traditionally used as a key to the diagnosis of amyotrophic lateral sclerosis (ALS), although relaxation of the tongue is often difficult to achieve. Recently, frequent abnormalities in the EMGs of the sternocleidomastoid (SCM) and upper trapezius muscles in ALS have been reported. To elucidate the diagnostic utility of these muscles we performed a multicenter prospective study to examine EMGs of the tongue (genioglossus), SCM, and trapezius in 104 ALS or suspected ALS patients. We also examined EMGs of the SCM and trapezius in 32 cervical spondylosis (CS) patients. We mainly evaluated fibrillation potentials/positive sharp waves (Fib/PSWs) and fasciculation potentials. Complete relaxation was achieved in 85% of ALS patients in the trapezius, but in only 6% of patients in the tongue. Fib/PSWs were observed in 8%, 13%, and 45% of ALS patients in the tongue, SCM, and trapezius, respectively, whereas fasciculation potentials were observed in 1%, 7%, and 39%, respectively. Abnormal spontaneous activity of any type was found in 9%, 17%, and 63% of patients, respectively. The high frequency of abnormal spontaneous activity in the trapezius was similar among the different diagnostic categories, and even 72% of clinically suspected ALS (progressive muscular atrophy) patients showed them in their trapezius. We did not observe Fib/PSWs or fasciculation potentials in any of our CS patients, thus these findings have excellent specificity. Tongue EMG added little utility over the clinical sign of tongue atrophy. Abnormal spontaneous activity in the trapezius would be more useful for the early diagnosis of ALS. Muscle Nerve 39: 63–70, 2009     

Needle electromyography of the frontalis muscle in patients with amyotrophic lateral sclerosis

Introduction: We sought to determine which muscles to choose for better assessment of the craniobulbar region in establishing the diagnosis of amyotrophic lateral sclerosis (ALS). Methods: We studied the frontalis muscle in 83 controls and compared it with the tongue, sternocleidomastoid (SCM), and trapezius muscles in 105 definite or probable ALS patients (54 bulbar, 51 nonbulbar). Results: More patients achieved complete relaxation of the frontalis muscle than the tongue or SCM. Motor unit potentials were of longer duration and higher amplitude in ALS patients than in controls (P < 0.05). The frontalis had the same frequency of spontaneous potentials as the tongue, SCM, and trapezius muscles in bulbar ALS patients, but fewer than in the trapezius in nonbulbar patients. Conclusions: Examining the frontalis provides useful information in establishing the diagnosis of ALS by identifying clinically evident or subclinical abnormalities in the craniobulbar region. Muscle Nerve 54 : 1093–1096, 2016     

Spontaneous electromyographic activity of the tongue in amyotrophic lateral sclerosis

Introduction: Detection of denervation in muscles in the craniobulbar area is important to assure widespread lower motor neuron involvement in the diagnosis of amyotrophic lateral sclerosis (ALS). The value of spontaneous activity analysis in needle electromyography (EMG) of the tongue has been questioned in the recent literature. Methods: Spontaneous activity in the tongue and sternocleidomastoid (SCM) muscles was reviewed retrospectively in 17 ALS patients. Results: Needle EMG showed spontaneous activity in the tongue in 14 of 17 patients (82%) and in 6 patients of 17 (35%) in SCM. Spontaneous EMG activity in the tongue was found in patients with and without bulbar symptoms. Conclusions: Needle EMG is a valuable method for assessing clinical and subclinical involvement of the tongue in patients with bulbar and limb onset ALS. Adequate relaxation of the tongue is a prerequisite for proper spontaneous activity recording. Muscle Nerve, 48: 296–298, 2013     

Prognostic value of EMG genioglossus involvement in amyotrophic lateral sclerosis

ObjectiveTo evaluate the prognostic value of needle electromyography (EMG) genioglossus involvement in patients with amyotrophic lateral sclerosis (ALS) at diagnosis.MethodsWe separately explored the prognostic value of clinical bulbar lower motor neuron (LMN) signs and EMG genioglossus involvement using Cox proportional hazard models adjusted for age, gender, diagnostic delay, presence of bulbar upper motor neuron (UMN) signs, EMG cervical and lumbosacral region involvement, ALSFRS-R score and C9Orf72 gene status. Then, we compared the prognostic value of EMG masseter and genioglossus abnormalities in a subset of patients in whom both muscles were analysed.Results103 ALS patients were included in the study. Neurophysiological genioglossus involvement was associated with a shorter survival (p = 0.002), a shorter time to moderate dysphagia (p = 0.0001) and to severe dysarthria (p = 0.012). Its prognostic value was still evident in patients without clinical bulbar LMN signs. Bulbar clinical LMN signs were only associated with an earlier onset of moderate dysphagia (p = 0.0001). EMG masseter abnormalities did not reach statistical significance with regard to all the clinical milestones.ConclusionsGenioglossus EMG at diagnosis could provide important information about ALS progression rate. The masseter muscle seems to be less involved in ALS.SignificanceEMG genioglossus involvement is a prognostic factor in ALS.