Van Paesschen W, Connelly A, Johnson C L, Duncan J S
Epilepsy Research Group, Great Ormond Street Hospital for Children, London, England.
Neurology. 1996 Oct;47(4):1021-31. doi: 10.1212/wnl.47.4.1021.
To establish a quantitative MRI technique using T2 relaxation time mapping to study systematically the amygdala in patients with intractable temporal lobe epilepsy (TLE).
Identification of a focal abnormality on MRI in patients with intractable TLE is important, because outcome from surgery depends largely on the removal of the underlying pathology. Hippocampal sclerosis (HS) is the most common cause of intractable TLE, but epileptogenic lesions can be confined to the amygdala.
Twenty control subjects and 82 patients with intractable TLE were studied. Patients who had foreign tissue lesions visible on routine MRI were excluded. All subjects had a hippocampal T2 map and volumetry and an amygdala T2 (AT2) map.
Forty-four of the 82 patients (54%) had an abnormal AT2, which was bilateral in 18. Forty-four patients (54%) had unilateral HS on MRI, 25 (57%) of whom had an abnormal AT2. Seven patients (8%) had bilateral HS, four of whom had an abnormal AT2. Thirty-one patients (38%) had normal quantitative hippocampal measures, 15 of whom had an abnormal AT2, which was bilateral in seven. Fluid attenuated inversion recovery (FLAIR) imaging, where appropriate, confirmed that the increased AT2 signal was due to parenchymal changes. Neuropathologic correlates of an increased AT2 included microdysgenesis in one and gliosis in three patients. Patients with an isolated AT2 abnormality were significantly older at the onset of habitual epilepsy and rarely had a history of febrile convulsions, in comparison with patients who had HS. An isolated AT2 abnormality correlated well with interictal EEG findings.
The combination of AT2 mapping and FLAIR is a sensitive method to detect lesions that are not seen on routine MRI in the amygdalae of patients with intractable TLE. Further correlational studies will be required to define the role of this technique in the presurgical evaluation of patients with intractable TLE.
建立一种利用T2弛豫时间成像的定量MRI技术，系统研究难治性颞叶癫痫（TLE）患者的杏仁核。
识别难治性TLE患者MRI上的局灶性异常很重要，因为手术结果很大程度上取决于潜在病变的切除。海马硬化（HS）是难治性TLE最常见的病因，但致痫性病变可能局限于杏仁核。
对20名对照受试者和82名难治性TLE患者进行研究。排除在常规MRI上可见有异物组织病变的患者。所有受试者均进行了海马T2成像及容积测量和杏仁核T2（AT2）成像。
82例患者中有44例（54%）AT2异常，其中18例为双侧异常。44例患者（54%）MRI显示单侧HS，其中25例（57%）AT2异常。7例患者（8%）为双侧HS，其中4例AT2异常。31例患者（38%）海马定量测量正常，其中15例AT2异常，7例为双侧异常。在适当情况下，液体衰减反转恢复（FLAIR）成像证实AT2信号增加是由于实质改变所致。AT2增加的神经病理学相关因素包括1例微小发育异常和3例胶质增生。与患有HS的患者相比，孤立性AT2异常的患者习惯性癫痫发作起始时年龄显著更大，且很少有高热惊厥病史。孤立性AT2异常与发作间期脑电图结果相关性良好。
AT2成像和FLAIR相结合是检测难治性TLE患者杏仁核常规MRI上未见病变的敏感方法。需要进一步的相关性研究来确定该技术在难治性TLE患者术前评估中的作用。
