^18氟标记脱氧葡萄糖正电子发射断层脑显像对癫痫患者致痫灶的定位和手术疗效的预测价值

目的：探讨^18氟标记脱氧葡萄糖（^18F－FDG）正电子发射断层（PET）脑显像皮质代谢改变与癫痫患者致痫灶的关系，及其对手术方式选择和疗效预测的价值。方法：经手术治疗的72例癫痫患者（男49例，女23例，平均年龄24岁）术前行^18F－FDG PET脑显像并与同期磁共振（MRI）、视频脑电图（VEEG）结果进行比较，全部进行了疗效随访（3－24个月，平均15个月），其中20例术后复查了^18F－FDG PET脑显像。结果：72例患者术前PET显像均有皮质代谢改变，1例表现发作期高代谢，71例表现发作间期低代谢。^18F－FDG代谢改变检出率高于MRI，其定位定侧准确性高于VEEG，但多发低代谢灶不一定全是致痫灶。术后FDG显像有助于判断低代谢灶性质。皮质低代谢灶合并同侧丘脑和／或对侧小脑代谢减低，术前术后显像对比表明系功能性变. 前FDG PET图像分型与手术方式和术后疗效相关。结论：手术前后FDG PET图像对比有助于评价代谢改变与癫痫灶的关系，代谢改变图型可帮助临床医生选择手术方式和预测疗效。

18F-FDG PET cerebral imaging for localizing epileptogenic foci and its relation to predicting operative outcome

OBJECTIVE: To find out the relationship between FDG PET image pattern and epileptogenic focus localization and predict prognosis by comparing pre- and post-surgical FDG images with operative effects. METHODS: 72 patients with epilepsy who underwent surgery (49M, 23F, aged 24.3 years on average) were studied with pre-surgical FDG PET cerebral imaging and followed up (av. 15 months, 3-24 months) for assessment of seizure control. 20 of them were studied with post-surgical FDG PET. The accuracy of localization of epileptogenic foci of FDG PET was compared with that of VEEG and MRI. The relationship between pre- and post-surgical FDG metabolic image pattern and surgical outcome was evaluated. RESULTS: (1) 71 patients showed pre-surgical interictal focal hypometabolism. 1 patient with continuous seizure showed ictal hypermetabolic focus. (2) FDG PET could localize the seizure foci in patients whose EEG showed bilateral or no definite epileptoform discharge. The rate of detection of epileptogenic foci with FDG PET was much higher than that with MRI. Since hypometabolic foci were non-specific, not all hypometabolic foci were epileptogenic. The correlation between postoperative FDG PET and surgical effect could help determine the nature of metabolic focus. (3) Hypometabolism of ipsilateral thalamus and/or contralateral cerebellum with temporal lobe lesion was secondary functional change. (4) The patternization of cerebral images was helpful to surgical planning and helped predict operative outcome. CONCLUSION: Comparison of pre-surgical with post-surgical FDG PET images help determine the nature of hypometabolic foci. The patternization of FDG PET images help the surgeon select patients, plan type of operation and predict surgical effect.