Wehner T, Lapresto E, Tkach J, Liu P, Bingaman W, Prayson R A, Ruggieri P, Diehl B
Epilepsy Center-S10, Cleveland Clinic, 9500 Euclid Ave., Cleveland, OH 44195, USA.
Neurology. 2007 Jan 9;68(2):122-7. doi: 10.1212/01.wnl.0000250337.40309.3d.
A subgroup of patients with nonlesional temporal lobe epilepsy (TLE) has no evidence of hippocampal sclerosis on standard temporal lobe protocol MRI.
To investigate whether interictal diffusion-weighted imaging adds lateralizing information in patients with TLE with and without lateralizing conventional MRI.
We studied 22 patients (9 right, 13 left TLE) who had undergone temporal lobectomy and 18 control subjects. We measured hippocampal volumes on high- resolution coronal magnetization-prepared rapid gradient echo scans. Apparent diffusion coefficients (ADCs) for the entire hippocampus and three arbitrarily defined areas of interest within the hippocampal head, body, and tail were measured from the coregistered ADC map. Pathology was reviewed and correlated with imaging findings.
Fourteen of 22 patients had hippocampal atrophy on MRI (defined as volume asymmetry greater than 2 SDs compared with asymmetry in the control group). Overall, resected hippocampi (n = 22) were significantly smaller than contralateral hippocampi as well as ipsilateral hippocampi in controls. ADCs were significantly higher in resected hippocampi than contralateral hippocampi as well as ipsilateral hippocampi in controls. These differences were also observed within the three areas of interest. ADCs in the hippocampi contralateral to the epileptogenic zone (n = 22) were also higher than in ipsilateral hippocampi in controls. In the subgroup of eight patients with nonlateralizing conventional MRIs, ADCs of resected hippocampi were not significantly different compared with the contralateral side. Pathology in these patients revealed gliosis only without apparent neuron loss.
Interictal apparent diffusion coefficients confirm lateralization in patients with hippocampal atrophy on standard temporal lobe protocol MRI. However, they do not provide lateralizing information in patients with nonlateralizing conventional MRI.
一部分非病灶性颞叶癫痫（TLE）患者在标准颞叶协议MRI上没有海马硬化的证据。
研究发作间期扩散加权成像是否能为有或没有定位传统MRI的TLE患者增加定位信息。
我们研究了22例接受颞叶切除术的患者（9例右侧TLE，13例左侧TLE）和18例对照者。我们在高分辨率冠状面磁化准备快速梯度回波扫描上测量海马体积。从配准的表观扩散系数（ADC）图测量整个海马以及海马头部、体部和尾部三个任意定义的感兴趣区域的ADC。回顾病理并与影像学结果进行关联。
22例患者中有14例在MRI上有海马萎缩（定义为与对照组不对称相比体积不对称大于2个标准差）。总体而言，切除的海马（n = 22）明显小于对侧海马以及对照组的同侧海马。切除的海马中的ADC明显高于对侧海马以及对照组的同侧海马。在三个感兴趣区域内也观察到了这些差异。癫痫发作区对侧海马（n = 22）中的ADC也高于对照组同侧海马。在8例传统MRI无定位的患者亚组中，切除海马的ADC与对侧相比无显著差异。这些患者的病理显示仅有胶质增生，无明显神经元丢失。
发作间期表观扩散系数证实了标准颞叶协议MRI上有海马萎缩患者的定位。然而，它们在传统MRI无定位的患者中不提供定位信息。
