Rubin E, Dhawan V, Moeller J R, Takikawa S, Labar D R, Schaul N, Barr W B, Eidelberg D
Department of Biological Psychiatry, Columbia University/New York State Psychiatric Institute, NY, USA.
Neurology. 1995 Dec;45(12):2212-23. doi: 10.1212/wnl.45.12.2212.
Fluorodeoxyglucose positron emission tomography (FDG-PET) studies of temporal lobe epilepsy (TLE) generally report interictal hypometabolism in the vicinity of the seizure focus. Yet, other evidence suggests that interictal metabolic abnormalities might extend to remote brain areas. We used FDG-PET to evaluate metabolism in selected regions distant from the focus in TLE.
Twenty adult patients with medically intractable TLE were selected by criteria favoring a unilateral mesiobasal temporal focus. Structural imaging in this sample were normal except for medial temporal sclerosis in 13 patients. Twenty normal volunteers were controls.
PET imaging was performed interictally. Regional glucose metabolism normalized by global metabolism was analyzed using t tests and correlation analysis.
Ipsilateral to the seizure focus, metabolism was depressed compared with normal in the temporal pole (p = 0.001), but relatively elevated in the mesiobasal region (p = 0.005). Contralateral to the focus, metabolism was elevated in lateral temporal cortex (p = 0.0003) and mesiobasal regions (p = 0.0001). Metabolic correlation between ipsilateral and contralateral mesiobasal regions was similar in normal subjects (r = 0.74) and patients (r = 0.68). In contrast, correlations were abnormal between temporal poles and other temporal lobe subregions, both ipsilateral and contralateral to the seizure focus.
Relative to normal values, both elevations and depressions of metabolism exist interictally in TLE. Such abnormalities, and accompanying changes in interregional correlations, may have wide spatial distribution. These findings are atypical among PET studies but are consistent with other physiologic, anatomic, and neuropsychological investigations of TLE.
颞叶癫痫（TLE）的氟脱氧葡萄糖正电子发射断层扫描（FDG-PET）研究通常报告发作间期癫痫灶附近代谢减低。然而，其他证据表明发作间期代谢异常可能会扩展到远处脑区。我们使用FDG-PET评估TLE患者远离癫痫灶的选定区域的代谢情况。
根据有利于单侧中基底颞叶癫痫灶的标准，选取了20例药物难治性TLE成年患者。该样本中的结构成像除13例患者有内侧颞叶硬化外均正常。20名正常志愿者作为对照。
在发作间期进行PET成像。使用t检验和相关分析对经全脑代谢标准化后的区域葡萄糖代谢进行分析。
与癫痫灶同侧，颞极代谢与正常相比减低（p = 0.001），但中基底区域代谢相对升高（p = 0.005）。与癫痫灶对侧，外侧颞叶皮质（p = 0.0003）和中基底区域（p = 0.0001）代谢升高。正常受试者同侧和对侧中基底区域之间的代谢相关性相似（r = 0.74），患者中也相似（r = 0.68）。相比之下，癫痫灶同侧和对侧颞极与其他颞叶亚区域之间的相关性均异常。
相对于正常值，TLE发作间期存在代谢升高和减低情况。这种异常以及区域间相关性的伴随变化可能具有广泛的空间分布。这些发现在PET研究中不典型，但与TLE的其他生理、解剖和神经心理学研究结果一致。
