Chan S, Chin S S, Kartha K, Nordli D R, Goodman R R, Pedley T A, Hilal S K
Department of Radiology, Neurological Institute of New York, USA.
AJNR Am J Neuroradiol. 1996 Oct;17(9):1725-31.
To investigate the phenomenon of reversible increased signal intensity of medial temporal lobe structures and cerebral neocortex seen on MR images of six patients with recent prolonged seizure activity.
After excluding patients with known causes of reversible signal abnormalities (such as hypertensive encephalopathy), we retrospectively reviewed the clinical findings and MR studies of six patients whose MR studies showed reversible signal abnormalities. MR pulse sequences included T2-weighted spin-echo coronal views or conventional short-tau inversion-recovery coronal images of the temporal lobes.
All six MR studies showed increased signal intensity within the medial temporal lobe, including the hippocampus in five studies. All follow-up MR examinations showed partial or complete resolution of the hyperintensity within the medial temporal lobe and the neocortex. In one patient, results of a brain biopsy revealed severe cerebral cortical gliosis. Temporal lobectomy performed 4 years later showed moderate cortical gliosis and nonspecific hippocampal cell loss and gliosis.
Significant hyperintensity within the temporal lobe is demonstrable on MR images after prolonged seizure activity, suggestive of seizure-induced edema or gliosis. Damage to medial temporal lobe structures by prolonged seizure activity indicates a possible mechanism of epileptogenic disorders.
研究6例近期有长时间癫痫发作活动患者的磁共振成像（MRI）上所见的内侧颞叶结构和大脑新皮质可逆性信号强度增加的现象。
在排除有已知可逆性信号异常原因（如高血压脑病）的患者后，我们回顾性分析了6例MRI显示可逆性信号异常患者的临床资料和MRI检查结果。MRI脉冲序列包括颞叶的T2加权自旋回波冠状位图像或传统的短反转时间反转恢复冠状位图像。
所有6例MRI检查均显示内侧颞叶信号强度增加，其中5例累及海马体。所有的随访MRI检查均显示内侧颞叶和新皮质内的高信号部分或完全消退。1例患者的脑活检结果显示严重的大脑皮质胶质增生。4年后进行的颞叶切除术显示中度皮质胶质增生以及非特异性海马体细胞丢失和胶质增生。
长时间癫痫发作活动后，MRI图像上可显示颞叶内明显的高信号，提示癫痫发作引起的水肿或胶质增生。长时间癫痫发作活动对内侧颞叶结构的损害表明了癫痫源性疾病的一种可能机制。
