The significance of bilateral CSI changes for the postoperative outcome intemporal lobe epilepsy

Purpose: In a prospective study, we evaluated the significance of preoperat ive bilateral chemical shift spectroscopy imaging (CSI) changes for the pro gnosis of postoperative seizure outcome in the surgical treatment of patien ts with temporal lobe epilepsy (TLE). Method: CSI using multivoxel spectroscopy was performed. Twenty-six consecu tive TLE patients scheduled for epilepsy surgery were included. To evaluate the value of the CSI with respect to postoperative seizure outcome, discri minant analysis with ipsilateral and contralateral CSI was performed. Results: The discriminant analysis showed that the contralateral metabolic changes alone an able to predict seizure outcome whereby 92.3% of cases wer e correctly classified. Upon comparison of the two groups of seizure-free a nd non-seizure-free patients with respect to contralateral metabolic change s, the difference proved to be highly significant (paired t test: t = -6.3, df = 24, p < 0.001). Conclusion: Bilateral metabolic CSI changes have a predictive value for the postoperative outcome in patients with TLE. In patients with severe bilate ral metabolic changes, poor seizure outcome is a likely result.