Center for Neuroimmunology, Service of Neurology, Hospital Clinic and Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.
PLoS One. 2012;7(5):e37167. doi: 10.1371/journal.pone.0037167. Epub 2012 May 14.
Corpus callosum (CC) is a common target for multiple sclerosis (MS) pathology. We investigated the influence of CC damage on physical disability and cognitive dysfunction using a multimodal approach.
Twenty-one relapsing-remitting MS patients and 13 healthy controls underwent structural MRI and diffusion tensor of the CC (fractional anisotropy; mean diffusivity, MD; radial diffusivity, RD; axial diffusivity). Interhemisferic transfer of motor inhibition was assessed by recording the ipsilateral silent period (iSP) to transcranial magnetic stimulation. We evaluated cognitive function using the Brief Repeatable Battery and physical disability using the Expanded Disability Status Scale (EDSS) and the MS Functional Composite (MSFC) z-score.
The iSP latency correlated with physical disability scores (r ranged from 0.596 to 0.657, P values from 0.004 to 0.001), and with results of visual memory (r = -0.645, P = 0.002), processing speed (r = -0.51, P = 0.018) and executive cognitive domain tests (r = -0.452, P = 0.039). The area of the rostrum correlated with the EDSS (r = -0.442, P = 0.045). MD and RD correlated with cognitive performance, mainly with results of visual and verbal memory tests (r ranged from -0.446 to -0.546, P values from 0.048 to 0.011). The iSP latency correlated with CC area (r = -0.345, P = 0.049), volume (r = -0.401, P = 0.002), MD (r = 0.404, P = 0.002) and RD (r = 0.415, P = 0.016).
We found evidence for structural and microstructural CC abnormalities associated with impairment of motor callosal inhibitory conduction in MS. CC damage may contribute to cognitive dysfunction and in less extent to physical disability likely through a disconnection mechanism.
胼胝体（CC）是多发性硬化症（MS）病变的常见靶点。我们采用多模态方法研究 CC 损伤对躯体残疾和认知功能障碍的影响。
21 例复发缓解型 MS 患者和 13 例健康对照者接受结构 MRI 和 CC 的弥散张量成像（各向异性分数；平均弥散度 MD；径向弥散度 RD；轴向弥散度 AD）检查。经颅磁刺激记录同侧静息期（iSP）以评估运动抑制的大脑半球间传递。我们使用简短重复电池评估认知功能，使用扩展残疾状况量表（EDSS）和多发性硬化功能复合量表（MSFC）z 分数评估躯体残疾。
iSP 潜伏期与躯体残疾评分相关（r 值范围为 0.596 至 0.657，P 值范围为 0.004 至 0.001），与视觉记忆（r=-0.645，P=0.002）、处理速度（r=-0.51，P=0.018）和执行认知领域测试（r=-0.452，P=0.039）的结果相关。喙部的面积与 EDSS 相关（r=-0.442，P=0.045）。MD 和 RD 与认知表现相关，主要与视觉和言语记忆测试的结果相关（r 值范围为-0.446 至-0.546，P 值范围为 0.048 至 0.011）。iSP 潜伏期与 CC 面积（r=-0.345，P=0.049）、体积（r=-0.401，P=0.002）、MD（r=0.404，P=0.002）和 RD（r=0.415，P=0.016）相关。
我们发现 MS 中存在与运动性胼胝体抑制性传导受损相关的结构和微观结构 CC 异常的证据。CC 损伤可能通过脱联机制导致认知功能障碍，在较小程度上导致躯体残疾。
