Jirsch Jeffrey D, Bernasconi Neda, Villani Flavio, Vitali Paolo, Avanzini Giuliano, Bernasconi Andrea
Montreal Neurological Institute and Hospital, Department of Neurology, McGill University, Quebec, Canada.
Hum Brain Mapp. 2006 Jun;27(6):535-43. doi: 10.1002/hbm.20197.
Subcortical band heterotopia is a diffuse malformation of cortical development related to pharmacologically intractable epilepsy. On magnetic resonance imaging (MRI), patients with "double cortex" syndrome (DCS) present with a band of heterotopic gray matter separated from the overlying cortex by a layer of white matter. The function and connectivity of the subcortical heterotopic band in humans is only partially understood. We studied six DCS patients with bilateral subcortical band heterotopias and six healthy controls using functional MRI (fMRI). In controls, simple motor task elicited contralateral activation of the primary motor cortex (M1) and ipsilateral activation of the cerebellum and left supplementary motor area (SMA). All DCS patients showed task-related contralateral activation of both M1 and the underlying heterotopic band. Ipsilateral motor activation was seen in 4/6 DCS patients. Furthermore, there were additional activations of nonprimary normotopic cortical areas. The sensory stimulus resulted in activation of the contralateral primary sensory cortex (SI) and the thalamus in all healthy subjects. The left sensory task also induced a contralateral activation of the insular cortex. Sensory activation of the contralateral SI was seen in all DCS patients and secondary somatosensory areas in 5/6. The heterotopic band beneath SI became activated in 3/6 DCS patients. Activations were also seen in subcortical structures for both paradigms. In DCS, motor and sensory tasks induce an activation of the subcortical heterotopic band. The recruitment of bilateral primary areas and higher-order association normotopic cortices indicates the need for a widespread network to perform simple tasks.
皮质下带状异位是一种与药物难治性癫痫相关的弥漫性皮质发育畸形。在磁共振成像（MRI）上，“双皮质”综合征（DCS）患者表现为一条异位灰质带，被一层白质与上方的皮质分隔开。人类皮质下异位带的功能和连接性仅得到部分了解。我们使用功能磁共振成像（fMRI）研究了6例双侧皮质下带状异位的DCS患者和6名健康对照者。在对照者中，简单运动任务引发对侧初级运动皮质（M1）激活以及同侧小脑和左侧辅助运动区（SMA）激活。所有DCS患者均表现出与任务相关的M1和其下方异位带的对侧激活。4/6例DCS患者出现同侧运动激活。此外，非初级正常皮质区域有额外激活。感觉刺激在所有健康受试者中导致对侧初级感觉皮质（SI）和丘脑激活。左侧感觉任务还诱导岛叶皮质对侧激活。所有DCS患者均出现对侧SI感觉激活，5/6例患者出现次级体感区激活。3/6例DCS患者SI下方的异位带被激活。两种范式在皮质下结构中也均可见激活。在DCS中，运动和感觉任务诱导皮质下异位带激活。双侧初级区域和高阶联合正常皮质的募集表明执行简单任务需要广泛的网络。
