Serles W, Li L M, Antel S B, Cendes F, Gotman J, Olivier A, Andermann F, Dubeau F, Arnold D L
Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada, H3A 2B4.
Epilepsia. 2001 Feb;42(2):190-7. doi: 10.1046/j.1528-1157.2001.01300.x.
To assess the time course of increases in N-acetyl-aspartate/creatine (NAA/Cr), which can be measured using proton MR spectroscopic imaging (1H-MRSI), in patients with intractable nonlesional temporal lobe epilepsy (TLE) after successful epilepsy surgery.
We performed pre- and postoperative 1H-MRSI in 16 seizure-free (SF) patients and 16 not seizure-free (NSF) TLE patients. We calculated a mixed-design analysis of variance (ANOVA) between SF and NSF groups, ipsi- and contralateral to the side of operation, and pre- and postoperative NAA/Cr measurements. We applied nonlinear regression between pre- and postoperative NAA/Cr differences and the time interval between 1H-MRSI scans to fit a negative exponential model to NAA recovery.
Mixed-design ANOVA revealed that (a) postoperative NAA/Cr was significantly higher in SF than in NSF patients (p = 0.02) and that (b) in the SF group, postoperative NAA/Cr values were significantly higher than preoperative values (p < 0.05) and returned to the normal range in most patients. According to our nonlinear regression model, in SF patients, there was a 50% increase relative to preoperative NAA/Cr values after 5.8 months, whereas an improvement of 95% was reached after 25 months.
Our results extend preliminary observations of postoperative NAA recovery of SF patients by characterizing the time course of recovery as an exponential function with a half-time of approximately 6 months. The reversal of neuronal metabolic dysfunction remote from the epileptic focus may underlie the clinical observation of improvement of cognitive dysfunction after successful epilepsy surgery.
评估难治性非损伤性颞叶癫痫（TLE）患者在癫痫手术成功后，通过质子磁共振波谱成像（1H-MRSI）测量的N-乙酰天门冬氨酸/肌酸（NAA/Cr）升高的时间进程。
我们对16例无癫痫发作（SF）患者和16例有癫痫发作（NSF）的TLE患者进行了术前和术后1H-MRSI检查。我们计算了SF组和NSF组之间、手术侧同侧和对侧以及术前和术后NAA/Cr测量值的混合设计方差分析（ANOVA）。我们对术前和术后NAA/Cr差异与1H-MRSI扫描之间的时间间隔进行非线性回归，以拟合NAA恢复的负指数模型。
混合设计方差分析显示，（a）SF组术后NAA/Cr显著高于NSF组患者（p = 0.02），且（b）在SF组中，术后NAA/Cr值显著高于术前值（p < 0.05），且大多数患者恢复到正常范围。根据我们的非线性回归模型，在SF患者中，相对于术前NAA/Cr值，5.8个月后增加了50%，而25个月后达到了95%的改善。
我们的结果通过将恢复时间进程表征为半衰期约为6个月的指数函数，扩展了对SF患者术后NAA恢复的初步观察。远离癫痫病灶的神经元代谢功能障碍的逆转可能是癫痫手术成功后认知功能障碍改善这一临床观察结果的基础。
