Dept. Clinical Neurophysiology, Centre for the Research and Rehabilitation of Hereditary Ataxias, Holguín, Cuba; Medical University of Holguin "Mariana Grajales", Holguín, Cuba.
Dept. Clinical Neurophysiology, Centre for the Research and Rehabilitation of Hereditary Ataxias, Holguín, Cuba; School of Physical Culture, University of Holguín, Holguín, Cuba.
Clin Neurophysiol. 2018 May;129(5):895-900. doi: 10.1016/j.clinph.2018.01.066. Epub 2018 Mar 15.
Corticospinal tract (CST) dysfunction is common in the pre-ataxic stage of spinocerebellar ataxia type 2 (SCA2) but quantitative assessment of its progression over time has not been explored. The aim of this study was to quantify the progression of CST dysfunction in pre-ataxic SCA2 using transcranial magnetic stimulation (TMS).
Thirty-three pre-ataxic SCA2 mutation carriers and a 33 age- and gender-matched healthy controls were tested at baseline and 2-years follow-up by standardized clinical exams, validated clinical scales, and TMS.
Pre-ataxic SCA2 mutation carriers showed a significant increase of resting motor thresholds (RMT) to abductor pollicis brevis (APB) and tibialis anterior (TA) muscles, and of central motor conduction time (CMCT) to TA at 2-years follow-up, over and above changes in healthy controls. The changes in the pre-ataxic SCA2 mutation carriers were independent of the presence of clinical signs of CST dysfunction at baseline, and independent of conversion to clinically definite SCA2 at 2-years follow-up.
TMS markers of CST dysfunction progress significantly during the pre-ataxic stage of SCA2.
TMS measures of CST dysfunction may provide biomarkers of disease progression prior to clinical disease expression that have potential utility for monitoring neuroprotective therapies in future clinical trials.
皮质脊髓束（CST）功能障碍在脊髓小脑性共济失调 2 型（SCA2）的前共济失调阶段很常见，但尚未探讨其随时间推移的进展情况。本研究旨在使用经颅磁刺激（TMS）定量评估前共济失调 SCA2 中 CST 功能障碍的进展。
33 名前共济失调 SCA2 突变携带者和 33 名年龄和性别匹配的健康对照者在基线和 2 年随访时接受了标准化的临床检查、经过验证的临床量表和 TMS 检查。
前共济失调 SCA2 突变携带者在 2 年随访时，与健康对照组相比，拇短展肌（APB）和胫骨前肌（TA）的静息运动阈值（RMT）以及 TA 的中枢运动传导时间（CMCT）显著增加。前共济失调 SCA2 突变携带者的变化独立于基线时 CST 功能障碍的临床体征，也独立于 2 年随访时转化为临床明确的 SCA2。
在 SCA2 的前共济失调阶段，CST 功能障碍的 TMS 标志物显著进展。
CST 功能障碍的 TMS 测量值可能在临床疾病表现之前提供疾病进展的生物标志物，对于未来临床试验中监测神经保护治疗具有潜在效用。
