Lizak Nathaniel, Clough Meaghan, Millist Lynette, Kalincik Tomas, White Owen B, Fielding Joanne
Department of Medicine, University of Melbourne, Melbourne, VIC, Australia; Monash School of Medicine, Monash University, Melbourne, VIC, Australia; School of Psychological Sciences, Monash Institute of Cognitive and Clinical Neurosciences, Monash University, Melbourne, VIC, Australia.
Department of Medicine, University of Melbourne, Melbourne, VIC, Australia; School of Psychological Sciences, Monash Institute of Cognitive and Clinical Neurosciences, Monash University, Melbourne, VIC, Australia.
Front Neurol. 2016 Nov 21;7:206. doi: 10.3389/fneur.2016.00206. eCollection 2016.
Multiple sclerosis (MS) is a diffuse disease that disrupts wide-ranging cerebral networks. The control of saccades and smooth pursuit are similarly dependent upon widespread networks, with the assessment of pursuit offering an opportunity to examine feedback regulation. We sought to characterize pursuit deficits in MS and to examine their relationship with disease duration.
Twenty healthy controls, 20 patients with a clinically isolated syndrome (CIS), and 40 patients with clinically definite MS (CDMS) participated. Thirty-six trials of Rashbass' step-ramp paradigm of smooth pursuit, evenly split by velocity (8.65°, 17.1°, and 25.9°/s) and ramp direction (left/right), were performed. Four parameters were measured: latency of pursuit onset, closed-loop pursuit gain, number of saccades, and summed saccade amplitudes during pursuit. For CDMS patients, these were correlated with disease duration and Expanded Disability Status Scale (EDSS) score.
Closed-loop pursuit gain was significantly lower in CIS than controls at all speeds. CDMS gain was lower than controls at medium pursuit velocity. CDMS patients also displayed longer pursuit latency than controls at all velocities. All patients accumulated increased summed saccade amplitudes at slow and medium pursuit speeds, and infrequent high-amplitude saccades at the fast speed. No pursuit variable significantly correlated with EDSS or disease duration in CDMS patients.
Smooth pursuit is significantly compromised in MS from onset. Low pursuit gain and increased saccadic amplitudes may be robust markers of disseminated pathology in CIS and in more advanced MS. Pursuit may be useful in measuring early disease.
多发性硬化症（MS）是一种弥漫性疾病，会破坏广泛的脑网络。扫视和平稳跟踪的控制同样依赖于广泛的网络，对跟踪的评估为检查反馈调节提供了机会。我们试图描述MS患者的跟踪缺陷，并研究它们与疾病持续时间的关系。
20名健康对照者、20名临床孤立综合征（CIS）患者和40名临床确诊的MS（CDMS）患者参与研究。进行了36次Rashbass平稳跟踪阶梯斜坡范式试验，按速度（8.65°、17.1°和25.9°/秒）和斜坡方向（左/右）平均分为两组。测量了四个参数：跟踪起始潜伏期、闭环跟踪增益、扫视次数以及跟踪期间扫视幅度总和。对于CDMS患者，将这些参数与疾病持续时间和扩展残疾状态量表（EDSS）评分进行相关性分析。
在所有速度下，CIS患者的闭环跟踪增益均显著低于对照组。在中等跟踪速度下，CDMS患者的增益低于对照组。在所有速度下，CDMS患者的跟踪潜伏期也比对照组更长。所有患者在慢和中等跟踪速度下的扫视幅度总和增加，在快速度下偶尔出现高幅度扫视。在CDMS患者中，没有任何跟踪变量与EDSS或疾病持续时间显著相关。
MS从发病开始平稳跟踪就受到显著损害。低跟踪增益和扫视幅度增加可能是CIS和更晚期MS中病变播散的有力标志。跟踪可能有助于早期疾病的测量。
