Objective: To investigate whether vestibular-evoked myogenic potentials(VEMPs) can be used to assess brainstem involvement in patients with Kennedy's disease (KD). Method: This was a case-control study.Twenty consecutive patients with genetically confirmed KD and 20 age-and sex-matched healthy subjects were enrolled from November 2018 to September 2020.All subjects were tested for three types of VEMPs, including cervical VEMP (c-VEMP) recorded by the sternocleidomastoid muscle (parameter:p13, n23), masseter VEMP (m-VEMP) recorded by the masseter muscle(parameter: p11), and ocular VEMP (o-VEMP) recorded by the inferior oblique muscle (parameter n10, p15).The latency of each wave, interside peak latency and interpeak latency of c-VEMP, the corrected amplitude and amplitude asymmetry ratio were recorded. Bilateral sternocleidomastoid muscle (SCMM) electromyography (EMG) was performed. The spinal cord and bulbous muscular atrophy functional rating scale (SBMAFRS) was used for assessment. Results: The mean p13 latency of c-VEMP was (15.5±1.4)ms, which was longer than that of the control group[(13.3±0.9)ms](P<0.05); the mean n23 latency was(25.5±1.4)ms, which was also longer than that of the control group[(22.5±1.0)ms] (P<0.05); the difference of bilateral p13[(2.3±0.6)ms] was significantly higher than that of the control group(P<0.05). The abnormal rates of c-, m-, o-VEMP in KD patients were 75%(15/20), 30%(6/20) and 20%(4/20), respectively. There was a significant positive correlation between c-VEMP latency and course of disease in KD patients(left: r=0.715, 0.695, right: r= 0.708, 0.715, both P<0.05). However, c-VEMP latency was negatively correlated with SBMAFRS score (left: r=-0.701, -0.694, right: r=-0.644, -0.685, both P<0.05). Abnormal rates of SCMM EMG in KD group were as follows: 15%(3/20)of patients showed spontaneous potential in resting state and 45% (9/20) of patients exhibited simple recruitment. Conclusions: The c-VEMP latency is a sensitive tool for detecting lower brainstem involvement in patients with KD, and the degree of damage increases with prolongation of disease course. The o-and m-VEMP abnormalities indicate that some KD patients develop upper brainstem damage.
目的： 探讨前庭诱发肌源性电位（VEMPs）是否可用于肯尼迪病（KD）脑干受累评估。 方法： 本研究为病例对照研究，收集北京大学第三医院自2018年11月至2020年9月KD患者20例（KD组），年龄和性别匹配的健康受试者20名（健康对照组）。所有受试者均检测三种类型VEMPs，包括胸锁乳突肌（SCMM）记录的 c-VEMP，参数p13、n23；咬肌记录的m-VEMP，参数p11；下斜肌记录的o-VEMP，参数n10、p15；记录各波的潜伏期，c-VEMP波间期、两侧差，校正波幅及波幅非对称比；同时行双侧SCMM针极肌电图检测；并使用脊髓和球部肌肉萎缩功能评定量表（SBMAFRS）评估。 结果： KD组患者c-VEMP的p13潜伏期［（15.5±1.4）ms］和n23潜伏期［（25.5±1.4）ms］均明显长于健康对照组［（13.3±0.9）ms，（22.5±1.0）ms］（均P<0.05）；双侧P13差值［（2.3±0.6）ms］，与健康对照组比较差异有统计学意义（P<0.05）。KD患者c-、m-、o-VEMP的异常率分别为75%（15/20），30%（6/20），20%（4/20）。KD患者c-VEMP潜伏期与病程呈正相关（左：r=0.715、0.695，右：r=0.708、0.715，均P<0.05）；与SBMAFRS评分呈负相关（左：r=-0.701，-0.694，右：r=-0.644，-0.685，均P<0.05）。KD组SCMM针极肌电图的异常率：安静状态下出现自发电位者15%（3/20）、大力收缩募集单纯相者45%（9/20）。 结论： c-VEMP的潜伏期是检测KD球部功能受累的敏感工具，损伤程度随病程延长而加重。o-VEMP和m-VEMP的损伤表明部分KD患者出现上脑干受累。.