Chambers Stefanie, Lazen Philipp, Hotka Matej, Shayeste Haniye, Tomschik Matthias, Wais Jonathan, Zeiser Vitalij, Hingerl Lukas, Strasser Bernhard, Haider Lukas, Traub-Weidinger Tatjana, Baumgartner Christoph, Koren Johannes, Mayer Florian, Feucht Martha, Dorfer Christian, Pataraia Ekaterina, Bogner Wolfgang, Trattnig Siegfried, Kasprian Gregor, Rössler Karl, Hangel Gilbert
Department of Neurosurgery, Medical University of Vienna, Austria.
MRCE, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Austria.
Eur J Neurol. 2025 Sep;32(9):e70343. doi: 10.1111/ene.70343.
Approximately one-third of people with epilepsy (PWE) remain drug-resistant. In these cases, surgical resection of the epileptogenic zone may significantly reduce or eliminate seizures. Surgery necessitates precise delineation of the epileptogenic zone (EZ) which proves especially challenging in the 20% of PWE that remain MRI-negative. The purpose of this study was to analyze the feasibility and robustness of ultra-high-field MRSI in identifying and characterizing pathologies in focal epilepsy. In addition, the relationship of glutamate and glutamine was evaluated in the EZ.
Fifty-six people with focal epilepsy were prospectively measured using 7 T concentric ring trajectory direct acquisition of free-induction-decay MRSI, which generated whole-brain metabolic maps with an isotropic resolution of 3.4mm. After exclusion criteria were applied, we assessed metabolite ratios in 15 lesional and 14 MRI-negative PWE.
In the lesional group, metabolic alterations in the suspected EZ were present in 86.7% of maps normalized to N-acetyl-aspartate, whereas this was reduced to 80% in creatine ratios. Metabolites with the highest consistency in the lesional group included myo-inositol and choline, showing increases in 92.3% of PWE. In MRI-negative patients, changes were heterogeneous, with a detection rate of 57.1%. We also observed a tendency toward an inverse relationship of glutamate to glutamine in the EZ, with increases of glutamine in PWE with lower seizure frequencies, contrasting glutamate increases in higher seizure frequencies.
Our preliminary analysis suggests that 7 T CRT-FID MRSI shows promise not only in identifying metabolic alterations in focal epilepsy but may also provide insights into disease pathomechanisms.
约三分之一的癫痫患者（PWE）仍存在药物抵抗。在这些情况下，手术切除致痫区可能会显著减少或消除癫痫发作。手术需要精确划定致痫区（EZ），而这在20%的MRI检查呈阴性的PWE患者中尤其具有挑战性。本研究的目的是分析超高场磁共振波谱成像（MRSI）在识别和表征局灶性癫痫病变中的可行性和稳健性。此外，还评估了EZ中谷氨酸和谷氨酰胺的关系。
对56例局灶性癫痫患者进行前瞻性测量，采用7T同心环轨迹直接采集自由感应衰减MRSI，生成各向同性分辨率为3.4mm的全脑代谢图谱。应用排除标准后，我们评估了15例有病变和14例MRI阴性的PWE患者的代谢物比率。
在有病变的组中，以N-乙酰天门冬氨酸为参照，86.7%的图谱显示可疑EZ存在代谢改变，而以肌酸比率为参照时，这一比例降至80%。有病变组中一致性最高的代谢物包括肌醇和胆碱，92.3%的PWE患者显示其增加。在MRI阴性的患者中，变化是异质性的，检出率为57.1%。我们还观察到EZ中谷氨酸与谷氨酰胺呈负相关的趋势，癫痫发作频率较低的PWE患者谷氨酰胺增加，而癫痫发作频率较高的患者谷氨酸增加。
我们的初步分析表明，7T CRT-FID MRSI不仅在识别局灶性癫痫的代谢改变方面显示出前景，还可能为疾病发病机制提供见解。
