Sarkar Prasenjit, Sherwani Poonam, Dev Rahul, Tiwari Ashutosh
Department of Radiodiagnosis and Department of Neurology, All India Institute of Medical Sciences, Rishikesh, India.
Hippocampus. 2023 Nov;33(11):1189-1196. doi: 10.1002/hipo.23572. Epub 2023 Aug 16.
Mesial temporal lobe epilepsy is one of the most common causes of refractory epilepsy worldwide. A good percentage of patients do not have detectable hippocampal atrophy on magnetic resonance imaging (MRI). The objective of this study is to evaluate whether T2 relaxometry can identify hippocampal pathology and lateralize the epileptic focus in patients with intractable temporal lobe epilepsy (TLE). T2 relaxometry can also be used to correlate the clinical severity of the disease with the relaxometry readings in those who have hippocampal atrophy as well as those who do not. Thirty two patients having clinical and electrophysiological features of TLE were enrolled and a MRI brain with T2 relaxometry was done. Hippocampal T2 relaxometry values were calculated in the head, body, and tail of the hippocampus and average T2 relaxometry values were calculated, and a comparison was done with the controls. For patients with unilateral involvement, the contralateral side was taken as control and in cases of bilateral involvement, controls were identified from normal subjects. T2 relaxometry is found to be superior to MR visual analysis in the early detection of cases of hippocampal sclerosis where there is no atrophy on visual analysis. Nine out of 32 patients (28%) were normal on MR visual analysis; however, showed increased values on T2 relaxometry, correlating with clinical and electrophysiological diagnosis. The rest of the patients with hippocampal atrophy showed a correlation of T2 relaxometry values with the degree of atrophy. The hippocampal T2 measurement is thus more sensitive and specific. The study was clinically significant (p < .0001). There was a mild female predilection of the disease and there was no significant correlation with comorbidities. There was a strong positive correlation with patients having a history of febrile seizures in childhood. T2 relaxometry may accurately lateralize the majority of patients with persistent TLE and offers evidence of hippocampus injury in those patients who do not show evidence of atrophy on MRI and also the T2 relaxometry values correlated with the degree of atrophy. Early identification of hippocampal sclerosis is crucial for prompt management which offers better outcomes.
内侧颞叶癫痫是全球难治性癫痫最常见的病因之一。相当一部分患者在磁共振成像（MRI）上没有可检测到的海马萎缩。本研究的目的是评估T2弛豫测量法能否识别难治性颞叶癫痫（TLE）患者的海马病变并确定癫痫病灶的侧别。T2弛豫测量法还可用于将疾病的临床严重程度与有海马萎缩和无海马萎缩患者的弛豫测量读数相关联。纳入了32例具有TLE临床和电生理特征的患者，并进行了带有T2弛豫测量的脑部MRI检查。计算海马头部、体部和尾部的海马T2弛豫测量值，并计算平均T2弛豫测量值，然后与对照组进行比较。对于单侧受累的患者，以对侧作为对照；对于双侧受累的病例，从正常受试者中确定对照。发现在早期检测视觉分析无萎缩的海马硬化病例中，T2弛豫测量法优于MR视觉分析。32例患者中有9例（28%）MR视觉分析正常；然而，T2弛豫测量值升高，与临床和电生理诊断相关。其余有海马萎缩的患者显示T2弛豫测量值与萎缩程度相关。因此，海马T2测量更敏感和特异。该研究具有临床意义（p < 0.0001）。该疾病有轻微的女性倾向，与合并症无显著相关性。与有儿童热性惊厥病史的患者有很强的正相关。T2弛豫测量法可能准确地确定大多数持续性TLE患者的癫痫病灶侧别，并为那些MRI上无萎缩证据的患者提供海马损伤的证据，而且T2弛豫测量值与萎缩程度相关。早期识别海马硬化对于及时管理至关重要，这能带来更好的结果。
