BACKGROUND The Symbol Digit Modalities Test (SDMT) is regarded as the cognitive test of choice for people with MS (pwMS). While deficits are linked to impaired processing speed, the mechanisms by which they arise are unclear. Cognitive-mediated eye movements offer one putative explanation. The objective of this study was to determine the association between eye movements and performance on the SDMT. METHODS Thirty-three people with confirmed MS and 25 matched healthy control subjects (HC) were administered the oral SDMT while eye movements were recorded. RESULTS Mean SDMT scores were significantly lower in pwMS (p < 0.038). Shorter mean saccade distance in the key area (p = 0.007), more visits to the key area per response (p = 0.014), and more total number of fixations in the test area (p = 0.045) differentiated pwMS from HCs. A hierarchical regression analysis revealed that the number of visits to the key area per response (p < 0.001; ΔR2 = 0.549) and total number of fixations in the test area (p < 0.001; ΔR2 = 0.782) were the most robust predictors of SDMT scores. CONCLUSION Cognitive-mediated eye movements help elucidate the processing speed challenges confronted by people with MS. Mechanistic insights such as these can potentially help inform new cognitive rehabilitation strategies.

中文翻译：

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SDMT期间认知介导的眼球运动揭示了MS患者面临的处理速度挑战。

背景技术符号数字模态测试（SDMT）被认为是MS患者（pwMS）的首选认知测试。尽管缺陷与处理速度降低有关，但其产生的机制尚不清楚。认知介导的眼球运动提供了一种假定的解释。这项研究的目的是确定SDMT上的眼球运动与表现之间的关联。方法对33例经确诊的MS患者和25例匹配的健康对照受试者（HC）进行SDMT口服，同时记录眼动情况。结果pwMS中SDMT的平均得分显着降低（p <0.038）。关键区域的平均扫视距离更短（p = 0.007），每次响应对关键区域的探访次数更多（p = 0.014），并且在测试区域将更多的固定物（p = 0.045）与HC区别开来。分层回归分析显示，每个响应对关键区域的访问次数（p <0.001;ΔR2= 0.549）和测试区域中注视的总数（p <0.001;ΔR2= 0.782）是SDMT的最可靠预测指标分数。结论认知介导的眼球运动有助于阐明MS患者面临的处理速度挑战。诸如此类的机械洞察力可能有助于提供新的认知康复策略。