Department of Radiology and Oncology, Laboratory of Medical Investigation (LIM-44), Faculdade de Medicina FMUSP, Universidade de Sao Paulo, Sao Paulo, SP, Brazil.
Department of Neurology, Hospital das Clínicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, SP, Brazil.
Mult Scler Relat Disord. 2018 May;22:41-48. doi: 10.1016/j.msard.2018.03.001. Epub 2018 Mar 6.
Low-education attainment is associated with worse cognitive performance in multiple sclerosis (MS) patients, and possibly with a lower cognitive reserve and/or increased inflammatory activity. Cognitive reserve refers to the capability of a source of intellectual enrichment in attenuating a negative effect of a disease-related factor; while the inflammatory activity is often related to T2-lesion load (T2-LL) increase.
To disentangle the effects of cognitive reserve and an increased T2-LL in MS-patients with low-education levels.
The study included 136 MS patients and 65 healthy-controls, divided in low-education (12 years or less of school education without obtaining any technical superior degree) and high-education (more than 12 years of school education with technical or superior degree) groups. An extensive battery of neuropsychological tests was applied examining intelligence quotient and six cognitive domains. Test results were z-scored and subjects with z-scores ≤ -1.5 in two or more domains were considered cognitively impaired. To test the factors associated with worse cognitive performance, regression models were applied using average cognition as target; education level, Expanded Disability Status Scale (EDSS), T2-LL, disease duration, age of disease onset, age and gender as predictors. We also tested the correlation between T2-LL and cognition in the groups. To investigate the role of education level as a source of intellectual enrichment/cognitive reserve in different stages of MS, we sub-divided the MS patients in three groups according to the disease duration (less than 5 years, between 5 and 10 years and more than 10 years).
Worse average cognition was associated with low-education level, higher T2-LL and male gender. A higher frequency of cognitively impaired patients was observed in MS patients with low-education level, in all stages of the disease. In patients with a disease duration shorter than five years, there was a lower correlation between worse average cognition and T2-LL in the high-education level group, compared to the patients with low-education level; in MS patients with longer disease duration, we observed a stronger correlation between lesion burden and cognitive impairment in both groups.
Education attainment is a source of intellectual enrichment and can enhance the cognitive reserve in MS patients. The protective effect of a high-education level was stronger in patients with less than five years of disease, suggesting a stronger role of cognitive reserve in short-term disease. In long-term disease we observed a greater impact of increased inflammatory activity on cognition.
低教育水平与多发性硬化症（MS）患者认知表现较差有关，可能与认知储备较低和/或炎症活动增加有关。认知储备是指智力来源的能力，可以减轻与疾病相关因素的负面影响；而炎症活动通常与 T2 病变负荷（T2-LL）增加有关。
在低教育水平的 MS 患者中，分别探讨认知储备和 T2-LL 增加的作用。
该研究纳入了 136 名 MS 患者和 65 名健康对照者，分为低教育（12 年或以下学校教育，未获得任何技术高等学位）和高教育（12 年以上学校教育，具有技术或高等学位）组。应用广泛的神经心理学测试组合，评估智商和六个认知领域。测试结果为 z 分数，两个或更多领域 z 分数≤-1.5 的患者被认为认知受损。为了测试与认知表现较差相关的因素，使用平均认知作为目标，采用回归模型，将教育水平、扩展残疾状况量表（EDSS）、T2-LL、疾病持续时间、发病年龄、年龄和性别作为预测因子。我们还测试了 T2-LL 在各组中的相关性。为了研究教育水平作为智力来源/认知储备在 MS 不同阶段的作用，我们根据疾病持续时间将 MS 患者分为三组（<5 年、5-10 年和>10 年）。
较差的平均认知与低教育水平、更高的 T2-LL 和男性性别有关。低教育水平的 MS 患者中认知受损患者的频率更高，在疾病的所有阶段都是如此。在疾病持续时间<5 年的患者中，与低教育水平患者相比，高教育水平患者中较差的平均认知与 T2-LL 的相关性较低；在疾病持续时间较长的 MS 患者中，两组中病变负荷与认知障碍的相关性更强。
教育程度是智力的来源，可以增强 MS 患者的认知储备。高教育水平的保护作用在疾病持续时间<5 年的患者中更强，这表明认知储备在短期疾病中发挥更强的作用。在长期疾病中，我们观察到炎症活动增加对认知的影响更大。
