Reduced thalamocortical functional connectivity in temporal lobe epilepsy
Reduced thalamocortical functional connectivity in temporal lobe epilepsy
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DOI：
10.1111/epi.13085
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发表时间：
2015-10-01
期刊：
影响因子：
5.6
通讯作者：
Tracy, Joseph I.
中科院分区：
文献类型：
--
作者：
He, Xiaosong;Doucet, Gaelle E.;Tracy, Joseph I.
目的在颞叶癫痫(TLE)中，丘脑在癫痫样活动的传播和扩散中的作用是众所周知的。然而，丘脑皮质功能连接性(FC)在TLE中的完整性及其与特定癫痫发作模式的关系尚未确定。我们通过静息状态功能磁共振成像(FMRI)对单侧TLE患者进行了静息状态fMRI检查：仅有局灶性发作(左侧TLE 16例，右侧TLE 16例)和伴有全身性发作(左侧TLE 16例，右侧TLE 10例)的患者和16例匹配的对照组。在前额叶、运动、躯体感觉、顶枕和颞叶5个不重叠的皮质种子和同侧丘脑之间进行基于FC的丘脑分割，将每个丘脑分成5个相应的节段。结果与健康对照组相比，TLE患者发作期和非发作期丘脑后部和腹内侧部多个节段丘脑皮质Fc降低。我们的分割分析表明，这些丘脑区域在功能上与顶叶/枕叶和颞叶相连。在有局灶性癫痫发作的TLE患者中，这些区域丘脑皮质Fc的下降仅限于发作期半球。相反，同时具有局灶性和全身性癫痫样活动的TLE患者在发作期和非发作期丘脑中均显示Fc降低，涉及背外侧枕，该区域优先连接到顶叶和枕叶。有意义我们的数据首次提供了单侧TLE患者局部特异性丘脑皮质Fc降低的证据。此外，我们的结果表明，不同发作类型的患者表现出不同的丘顶/枕叶FC下降模式。局灶性癫痫患者仅在发作期半球表现为丘脑皮质Fc降低，而有额外全身性发作活动的患者也表现出累及非发作期半球丘脑的丘脑皮质Fc降低。
ObjectiveIn temporal lobe epilepsy (TLE), the thalamus is well known for its role in the propagation and spread of epileptiform activity. However, the integrity of thalamocortical functional connectivity (FC) in TLE and its relation to specific seizure patterns have not yet been determined. We address these issues with resting-state functional magnetic resonance imaging (fMRI).MethodsResting-state fMRI was performed on two groups of unilateral TLE patients: those with focal seizures only (16 left TLE, 16 right TLE) and those with additional generalized seizures (16 left TLE, 10 right TLE), and 16 matched controls. A thalamic parcellation based on FC between five nonoverlapping cortical seeds (prefrontal, motor, somatosensory, parietal-occipital, and temporal) and the ipsilateral thalamus was carried out to parcel each thalamus into five corresponding segments. FCs between each segment and its ipsilateral cortical seed were extracted and compared across groups using analyses of variance (ANOVAs).ResultsCompared to healthy controls, patients with TLE displayed decreased thalamocortical FC in multiple posterior and ventromedial thalamic segments of both the ictal and nonictal hemispheres. Our parcellation analysis revealed that these thalamic regions were functionally connected to the parietal/occipital and temporal lobes. In patients with TLE with focal seizures these regional thalamocortical FC decreases were limited to the ictal hemisphere. In contrast, TLE patients with both focal and generalized epileptiform activity displayed FC decreases in both the ictal and nonictal thalamus involving the dorsolateral pulvinar, a region preferentially connected to the parietal and occipital lobes.SignificanceOur data provide the first evidence of regional specific thalamocortical FC decreases in patients with unilateral TLE. Furthermore, our results demonstrate that patients with different seizure types present different thalamoparietal/occipital FC decrease patterns. While patients with focal seizures present thalamocortical FC decreases in the ictal hemisphere only, patients with additional generalized seizure activity also show thalamocortical FC decreases involving the thalamus in the nonictal hemisphere.