Reorganisation of the language system in epilepsy

脑外科手术治疗癫痫与认知障碍的风险有关。避免致残性术后损伤在很大程度上取决于我们在神经外科干预之前预测和测量语言侧化个体模式的能力。在癫痫性病变的患者中，不能假设典型的侧化模式。似乎有一种共识，即非典型表现在癫痫患者中比在正常人群中更常见，超过20%的值并非不具有代表性，部分癫痫起源于大脑的一个区域并扩散到其他区域。这与全身性癫痫形成对比，全身性癫痫似乎同时出现在整个大脑。部分性癫痫通常与肿瘤或海马硬化等病变有关，并且癫痫发作通常是难治性的。部分癫痫患者在语言区域有多种脑损伤来源。原发性大脑变化可能是预先存在的，这意味着它们早于习惯性癫痫发作的发生。它们可能包括局灶性发育异常（皮质发育畸形）或可能代表癫痫发作的一般遗传易感性。因此，部分癫痫不仅与癫痫发生区域的严重异常有关，而且还与双脑半球的其他广泛异常有关。也有证据表明异常与癫痫发作频率相关，有些人认为癫痫的持续时间也可能增加该半球的异常程度。语言皮层中导致侧化功能改变的神经元状况目前尚不清楚。本研究的主要目的是通过使用目前最灵敏的非侵入性方法来评估脑损伤和脑功能，即磁共振成像，来了解癫痫患者语言系统的重组。

Brain surgery for the treatment of epilepsy is associated with a risk of cognitive impairment. Avoidance of disabling post-operative impairments depends in large measure on our ability to predict and measure individual patterns of language lateralization prior to neurosurgical intervention. Typical patterns of lateralisation cannot be assumed in patients with epileptogenic lesions. There appears to be a consensus that atypical representation is more frequent in patients with epilepsy than it is in the normal population, and values above 20% are not unrepresentative Partial epilepsy arises from a region in the brain and spreads to involve other areas. This is contrasted with generalised epilepsy, which appears to arise all over the brain simultaneously. Partial epilepsy is often associated with lesions such as tumors or hippocampal sclerosis, and often seizures are intractable. Patients with partial epilepsy have a number of sources of brain damage in the language areas. Primary brain changes may be pre-existing, which means they pre-date the onset of habitual seizures. They may consist of a focal developmental abnormality (a malformation of cortical development) or may represent a general genetic predisposition to seizures. Therefore, partial epilepsy is not only associated with severe abnormalities in epileptogenic region but also with additional widespread abnormalities in both hemispheres. There is also evidence for a correlation of abnormalities with seizure frequency with some suggestion that the duration of epilepsy may also increase the degree of abnormality in the hemisphere. The neuronal conditions in language cortex that give rise to altered lateralisation in function are currently not known. The primary aim of this study is to understand reorganisation of the language system in epilepsy by using the current most sensitive non-invasive methods of assessing brain damage and brain function, using magnetic resonance imaging.