Multiple Sclerosis Center, Sheba Medical Center, Tel-Hashomer, Israel.
PLoS One. 2013 Aug 1;8(8):e71058. doi: 10.1371/journal.pone.0071058. Print 2013.
BACKGROUND/AIMS: Large-scale population studies measuring rates and dynamics of cognitive decline in multiple sclerosis (MS) are lacking. In the current cross-sectional study we evaluated the patterns of cognitive impairment in MS patients with disease duration of up to 30 years.
1,500 patients with MS were assessed by a computerized cognitive battery measuring verbal and non-verbal memory, executive function, visual spatial perception, verbal function, attention, information processing speed and motor skills. Cognitive impairment was defined as below one standard deviation (SD) and severe cognitive impairment as below 2SD for age and education matched healthy population norms.
Cognitive performance in our cohort was poorer than healthy population norms. The most frequently impaired domains were information processing speed and executive function. MS patients with secondary-progressive disease course performed poorly compared with clinically isolated syndrome, relapsing-remitting and primary progressive MS patients. By the fifth year from disease onset, 20.9% of patients performed below the 1SD cutoff for impairment, p=0.005, and 6.0% performed below the 2SD cutoff for severe cognitive impairment, p=0.002. By 10 years from onset 29.3% and 9.0% of patients performed below the 1SD and 2SD cutoffs, respectively, p=0.0001. Regression modeling suggested that cognitive impairment may precede MS onset by 1.2 years.
The rates of cognitive impairment in this large sample of MS patients were lower than previously reported and severe cognitive impairment was evident only in a relatively small group of patients. Cognitive impairment differed significantly from expected normal distribution only at five years from onset, suggesting the existence of a therapeutic window during which patients may benefit from interventions to maintain cognitive health.
背景/目的：缺乏大规模的人口研究来衡量多发性硬化症（MS）患者认知能力下降的速度和动态。在目前的横断面研究中，我们评估了病程长达 30 年的 MS 患者的认知障碍模式。
对 1500 名 MS 患者进行了计算机认知测试，测试内容包括言语和非言语记忆、执行功能、视觉空间感知、言语功能、注意力、信息处理速度和运动技能。认知障碍定义为低于一个标准差（SD），严重认知障碍定义为低于年龄和教育匹配的健康人群正常值 2SD。
我们队列的认知表现比健康人群的正常值差。受影响最严重的领域是信息处理速度和执行功能。继发进展性疾病病程的 MS 患者的表现不如孤立综合征、复发缓解型和原发性进展型 MS 患者。从发病后的第五年开始，20.9%的患者的认知功能低于 1SD 损伤的临界值，p=0.005，6.0%的患者的认知功能低于 2SD 严重认知损伤的临界值，p=0.002。发病 10 年后，29.3%和 9.0%的患者分别低于 1SD 和 2SD 临界值，p=0.0001。回归建模表明，认知障碍可能在 MS 发病前 1.2 年出现。
在这个大型 MS 患者样本中，认知障碍的发生率低于之前的报道，只有在相对较小的患者群体中才会出现严重的认知障碍。只有在发病后五年，认知障碍才明显偏离预期的正态分布，这表明存在一个治疗窗口，在此期间，患者可能受益于干预措施来保持认知健康。
