Introduction: Vestibular Evoked Myogenic Potential (VEMP) can be used to test central vestibular pathways from the midbrain to the lumbar spine, according to the muscle tested. Purpose: to compare the spinal cord alteration in individuals with HTLV-1-associated myelopathy (HAM) and with HTLV-1-asymptomatic infection using the VEMP recorded from different muscles. Methods: VEMP was recorded in 90 individuals of whom 30 had HAM, 30 were HTLV-1 asymptomatic carriers, and 30 negative controls. VEMP was recorded in the oculomotor muscle (oVEMP), testing the vestibulo-ocular reflex, and in the cervical muscle (cVEMP) and soleus muscle (sVEMP), testing the vestibulospinal reflex, respectively, in the cervical and in the lumbar spinal level. The type of stimulation was auditory for oVEMP and cVEMP, and galvanic for sVEMP. The compared variables were the latencies of the electrophysiological waves. Results: HTLV-1-asymptomatic group was similar to the controls regarding oVEMP (p = 0.461), but different regarding cVEMP (p < 0.001) and sVEMP (p < 0.001). HAM group has presented the worst latencies and was different from the HTLV-1-asymptomatic group in the VEMP of all the tested muscles (p < 0.001). The concomitant occurrence of VEMP alterations in the three recorded muscles of the same individual was found in 2 (6.7%) asymptomatic carriers and in 20 (66.7%) patients with HAM (p = 0.001). The analysis of VEMP alteration per group and per muscle has showed that, in HTLV-1-asymptomatic group, oVEMP was altered in 3 (10.0%) individuals, cVEMP in 10 (33.3%) and sVEMP in 13 (43.3%). In HAM group, oVEMP was altered in 23 (76.6%) individuals, cVEMP in 27 (90%), and sVEMP in 30 (100%). Conclusion: HTLV-1-neurological damage has followed an ascendant progression beginning at the lumbar spine in the stage of a clinically asymptomatic infection, whereas HAM has affected not only the spine, but also the midbrain.

中文翻译：

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前庭在眼，颈和比目鱼肌上诱发肌原性电位，以评估HTLV-1感染中神经功能障碍的程度。

简介：根据所测试的肌肉，前庭诱发的肌原性电位（VEMP）可用于测试从中脑到腰椎的中央前庭通路。目的：使用从不同肌肉记录的VEMP，比较HTLV-1相关性脊髓病（HAM）和HTLV-1无症状感染的个体的脊髓改变。方法：记录90例VEMP，其中HAM 30例，HTLV-1无症状携带者30例，阴性对照30例。VEMP分别记录在动眼肌（oVEMP），测试前庭眼反射，以及宫颈肌（cVEMP）和比目鱼肌（sVEMP），测试前庭脊髓反射在颈椎和腰椎水平。对于oVEMP和cVEMP，刺激的类型是听觉的，对于sVEMP，刺激的类型是电流的。比较的变量是电生理波的潜伏期。结果：HTLV-1无症状组在oVEMP方面与对照组相似（p = 0.461），但在cVEMP（p <0.001）和sVEMP（p <0.001）方面有所不同。HAM组表现出最差的潜伏期，并且在所有测试肌肉的VEMP中与HTLV-1无症状组不同（p <0.001）。在2例（6.7％）无症状携带者和20例（66.7％）HAM患者中发现同一个人的三个记录的肌肉中同时发生VEMP改变（p = 0.001）。对每组和每条肌肉的VEMP改变的分析表明，在HTLV-1无症状组中，oVEMP改变了3（10.0％），cVEMP改变了10（33.3％），sVEMP改变了13（43.3％）。在HAM组中，oVEMP改变了23（76.6％）人，cVEMP改变了27（90％），和sVEMP中的30（100％）。结论：在临床无症状感染的阶段中，从腰椎开始，HTLV-1的神经损伤开始上升，而HAM不仅影响脊柱，还影响中脑。