摘要目的:探讨颅段受累肌萎缩侧索硬化（ALS）患者临床及电生理的分裂脸现象。方法:回顾性收集2019年9月至2022年11月于天津市第三中心医院就诊的符合世界神经病学联盟El Escorial诊断标准的确诊及很可能的颅段受累ALS 患者52例，同时收集同期于天津市第三中心医院神经内科就诊的发病时间≤7 d的特发性面神经麻痹患者58例作为对照组。采用用力闭目评分和鼓腮评分评估ALS患者临床面部肌肉受累情况（分为面肌受累组和无面肌受累组）及分裂脸现象（闭目有力而鼓腮力弱）是否存在。采用Nicolet Viking EDX肌电诱发电位仪检测全部受试者双侧眼轮匝肌和口轮匝肌的复合肌肉动作电位（CMAP）波幅，并计算波幅比，比较颅段受累ALS 患者及特发性面神经麻痹患者的面神经神经电生理差异。电生理数据多组间比较采用Kruskal-Wallis H检验，多组间的两两比较采用Bonferroni法。采用二分类Logistic回归逐步法筛选颅段受累ALS患者面肌受累的相关因素。使用受试者工作特征曲线（ROC）评估有面肌受累症状时面神经电生理检测对ALS的诊断价值。 结果:52例颅段受累ALS患者中有20例患者（38.5%）存在面部肌肉受累，均为双侧受累，16例患者（30.8%）仅有鼓腮无力，1例（1.9%）仅有闭目无力，3例（5.8%）闭目、鼓腮均无力。面肌受累组修订版ALS 功能评定量表（ALSFRS-R）评分（分）较无面肌受累组低（36.90±9.20比40.75±5.21， t=2.419， P=0.019），用力闭目评分、鼓腮评分（分）较无面肌受累组高［用力闭目评分：0（0，1）比0（0，0）， U=5.854， P<0.001；鼓腮评分：4（3，4）比0（0，0）， U=9.069， P<0.001］，差异均有统计学意义。面肌受累组眼轮匝肌CMAP波幅与特发性面神经麻痹组健侧、特发性面神经麻痹组患侧、无面肌受累组比较差异均无统计学意义（均 P>0.05）。面肌受累组口轮匝肌CMAP波幅［1 100.00（775.00，1 375.00）μV］较特发性面神经麻痹健侧［1 800.00（1 400.00，2 300.00）μV］、无面肌受累组［1 555.00（1 202.50，1 980.00）μV］低，差异均有统计学意义（ H=5.884， P<0.001； H=4.114， P<0.001）。面肌受累组口轮匝肌CMAP波幅与特发性面神经麻痹组患侧比较差异无统计学意义（ P>0.05）。面肌受累组眼轮匝肌/口轮匝肌CMAP波幅比［0.83（0.51，1.14）］较特发性面神经麻痹健侧［0.55（0.39，0.73）］、特发性面神经麻痹组患侧［0.57（0.40，0.73）］、无面肌受累组［0.60（0.42，0.71）］高，差异有统计学意义（ H=-3.440， P=0.003； H=-3.433， P=0.004； H=-3.225， P=0.008）。Logistic回归分析结果显示，口轮匝肌CMAP波幅（ OR=0.998，95% CI 0.997~0.999， P<0.001）、ALSFRS-R评分（ OR=0.916，95% CI 0.857~0.979， P=0.010）为颅段受累ALS患者面肌受累的相关因素。ROC 曲线分析结果显示面肌受累组眼轮匝肌CMAP的曲线下面积（AUC）为0.629，口轮匝肌CMAP的 AUC为0.838，眼轮匝肌/口轮匝肌CMAP波幅比的AUC为0.690。 结论:颅段受累ALS患者存在闭目有力而鼓腮力弱的分裂脸现象。颅段受累ALS患者有面肌受累症状时，口轮匝肌CMAP波幅显著下降，眼轮匝肌CMAP波幅下降不显著，亦存在分裂现象。

abstractsObjective:To explore the split-face phenomenon in patients with bulbar-involved amyotrophic lateral sclerosis (ALS) through clinical and electrophysiological studies.Methods:A total of 52 clinically definite and clinically probable cases of bulbar-involved ALS, diagnosed according to the World Federation of Neurology El Escorial criteria, were retrospectively collected in the Third Central Hospital of Tianjin from September 2019 to November 2022. And 58 patients with idiopathic facial nerve paralysis with onset time≤7 days who visited the Department of Neurology of the Third Central Hospital of Tianjin during the same period were collected as control group. The firm eye closure (FC) score and cheek bulge (CB) score were used to assess the clinical involvement of facial muscles (dividing into facial muscle involvement group and non-facial muscle involvement group) and the presence of the split-face phenomenon (strong eye closure and weak cheek bulging) in ALS patients. The compound muscle action potential (CMAP) amplitudes of the bilateral orbicularis oculi and orbicularis oris muscles were measured using the Nicolet EDX Viking electromyography/evoked potential system. The CMAP amplitude ratio was calculated. The facial nerve electrophysiological differences were compared between ALS patients with bulbar involvement and patients with idiopathic facial nerve paralysis. The analysis of electrophysiological data across various groups was carried out utilizing the Kruskal-Wallis H test, while pairwise comparisons between groups were executed employing the Bonferroni correction method. Additionally, a stepwise binary Logistic regression analysis was implemented to ascertain the factors associated with facial muscle involvement in patients with bulbar-involved ALS. The receiver operating characteristic (ROC) curve was used to assess the diagnostic accuracy of facial nerve electrophysiological testing in diagnosing ALS in the presence of symptoms of facial muscle involvement. Results:Among the 52 ALS patients with bulbar involvement, there were 20 cases (38.5%) with facial muscle involvements, all of which were bilateral; 16 patients (30.8%) exhibited weakness solely in the ability to puff their cheeks, 1 patient (1.9%) presented with weakness exclusively in closing the eyes, and 3 patients (5.8%) experienced weakness in both closing the eyes and puffing the cheeks. The Revised Amyotrophic Lateral Sclerosis Functional Rating Scale (ALSFRS-R) score of the facial muscle involvement group was lower compared to the non-facial muscle involvement group (36.90±9.20 vs 40.75±5.21, t=2.419, P=0.019), while the FC score and CB score were higher in the facial muscle involvement group [FC score: 0(0, 1) vs 0(0, 0), U=5.854, P<0.001; CB score: 4(3, 4) vs 0(0, 0), U=9.069, P<0.001], showing statistically significant differences. There was no statistically significant difference in the CMAP amplitude of the orbicularis oculi muscle between the facial muscle involvement group and the healthy side of the idiopathic facial nerve paralysis group, the affected side of the idiopathic facial nerve paralysis group, and the non-facial muscle involvement group (all P>0.05). The CMAP amplitude of the orbicularis oris muscle in the facial muscle involvement group [1 100.00 (775.00, 1 375.00) μV] was lower than that in the healthy side of the idiopathic facial nerve paralysis group [1 800.00 (1 400.00, 2 300.00) μV] and the non-facial muscle involvement group [1 555.00 (1 202.50, 1 980.00) μV], with statistically significant differences ( H=5.884, P<0.001; H=4.114, P<0.001). There was no statistically significant difference in the CMAP amplitude of the orbicularis oris muscle between the facial muscle involvement group and the affected side of the idiopathic facial nerve paralysis group ( P>0.05). The CMAP amplitude ratio of the orbicularis oculi/orbicularis oris muscles in the facial muscle involvement group [0.83(0.51, 1.14)] was higher than that in the healthy side of the idiopathic facial nerve paralysis group [0.55(0.39, 0.73)], the affected side of the idiopathic facial nerve paralysis group [0.57(0.40, 0.73)], and the non-facial muscle involvement group [0.60(0.42, 0.71)], with statistically significant differences ( H=-3.440, P=0.003; H=-3.433, P=0.004; H=-3.225, P=0.008). Logistic regression analysis revealed that the CMAP amplitude of orbicularis oris muscle ( OR=0.998,95% CI 0.997-0.999, P<0.001) and ALSFRS-R score ( OR=0.916,95% CI 0.857-0.979, P=0.010) were factors associated with facial muscle involvement in ALS patients with bulbar involvement. The ROC curve analysis results showed that the area under the curve (AUC) of the orbicularis oculi muscle CMAP was 0.629, the AUC of the orbicularis oris muscle CMAP was 0.838, and the AUC of the CMAP amplitude ratio of the orbicularis oculi/orbicularis oris muscles was 0.690 in the facial muscle involvement group. Conclusions:Patients with bulbar-involved ALS have split-face phenomenon characterized by strong eye closure and weak cheek bulging. When bulbar-involved ALS patients have symptoms of facial muscle involvement, the CMAP amplitude of the orbicularis oris muscle decreases significantly, whereas the CMAP amplitude of the orbicularis oculi muscle remains relatively stable, further illustrating the split phenomenon.