Nelson F, Steinberg J
University of Texas Health Science Center at Houston, Houston, TX, USA.
Virginia Commonwealth University Richmond, VA, USA.
J Neurol Disord Stroke. 2013 Sep;1(2):1011.
Functional MRI (fMRI) basic cognitive paradigms such as the n-back have been shown to detect cognitive impairment (CI) in Multiple Sclerosis (MS). The immediate memory task/delayed memory task (IMT/DMT) detects varying degrees of working memory (WM) by alternating three levels of complexity and two levels of WM delay. This paradigm has not been evaluated in MS nor validated against standard neuropsychological (NP) testing.
To evaluate the correlation between WM function and blood oxygen level dependent (BOLD) activation on fMRI in MS patients undergoing the IMT/DMT. To compare IMT/DMT behavioral scores to NP scores.
10 MS patients with no history of CI underwent the Minimal Assessment of Cognitive Function in MS (MACFIMS) and an fMRI session where they performed the IMT/DMT. Working-memory ("wmem") activation was defined as the BOLD signal during DMT blocks for a particular condition (3, 5, or 7 digits per stimuli) minus the BOLD signal during IMT blocks for that condition. Areas of statistically significant Family Wise Error (FWE) -corrected cluster-level BOLD activation were identified using SPM8 Random Effects t-test. IMT/DMT behavioral data and MACFIMS scores were compared.
The 3-digit as well as the 5-digit wmem showed significant fMRI BOLD activation. The 3-digit wmem, activation was found in portions of the bilateral superior and mid frontal cortex, supplementary motor area, pre and post central gyrus, bilateral superior and inferior parietal lobule, inferolateral pre-frontal cortex, cuneus, insula and cingulate regions. The 5 digit wmen activation was seen in the inferior medial frontal and medial orbitofrontal cortex. IMT/DMT behavioral scores were within normal range and consistent with MACFIMS.
IMT/DMT, a novel fMRI working memory paradigm, is associated with BOLD activation in areas of the brain related to cognitive function in patients with MS. Both MACFIMS and IMT/DMT scores were in agreement and supported intact cognitive function.
功能磁共振成像（fMRI）的基本认知范式，如n-back范式，已被证明可检测多发性硬化症（MS）中的认知障碍（CI）。即时记忆任务/延迟记忆任务（IMT/DMT）通过交替三种复杂度水平和两种工作记忆（WM）延迟水平来检测不同程度的工作记忆。该范式尚未在MS中进行评估，也未与标准神经心理学（NP）测试进行验证。
评估接受IMT/DMT的MS患者中，工作记忆功能与fMRI上血氧水平依赖（BOLD）激活之间的相关性。比较IMT/DMT行为评分与NP评分。
10名无CI病史的MS患者接受了MS认知功能最小评估（MACFIMS）和一次fMRI检查，期间他们执行IMT/DMT。工作记忆（“wmem”）激活定义为特定条件下（每个刺激3、5或7位数字）延迟记忆任务（DMT）块期间的BOLD信号减去该条件下即时记忆任务（IMT）块期间的BOLD信号。使用SPM8随机效应t检验确定具有统计学显著的家族性错误率（FWE）校正的簇水平BOLD激活区域。比较IMT/DMT行为数据和MACFIMS评分。
3位数字以及5位数字的wmem均显示出显著的fMRI BOLD激活。3位数字的wmem激活出现在双侧额上回和额中回、辅助运动区、中央前回和中央后回、双侧顶上小叶和顶下小叶、额下外侧皮质、楔叶、岛叶和扣带区域的部分区域。5位数字的wmem激活出现在额内侧下部和眶额内侧皮质。IMT/DMT行为评分在正常范围内，与MACFIMS一致。
IMT/DMT是一种新型的fMRI工作记忆范式，与MS患者大脑中与认知功能相关区域的BOLD激活有关。MACFIMS和IMT/DMT评分一致，支持认知功能完好。
