1H-MR spectroscopy indicates severity markers in temporal lobe epilepsy:: Correlations between metabolic alterations, seizures, and epileptic discharges in EEG

Purpose: In this study, hippocampal metabolite alterations in H-1-MR spectroscopy (H-1-MRS) were correlated to the findings of intensive video-EEG monitoring and duration of seizure symptoms in patients with temporal lobe epilepsy (TLE). Methods: The 14 patients with mesial TLE and no pathological findings in imaging were investigated by H-1-MRS. Seizures were analyzed by: number of clinical seizures in 24 h, exact duration of clinical symptoms in 24 h, frequency of interictal epileptiform discharges (IEDs) and ictal activity, duration of ictal activity, and IEDs occurring within 24 h in intensive EEG monitoring. Pearson Correlation Coefficient (PCC) was calculated between spectral metabolite alterations and the parameters mentioned above. Results: In the analysis, a negative correlation was found between total (t) NAA values and degree of IEDs in EEG (p = 0.04); a positive correlation was found between Cr levels and duration of seizure symptoms registered by video monitoring (p = 0.01). Conclusions: Our study shows that, in some patients, H-1-MRS is able to refer the severity of TLE. The degree of tNAA reduction in H-1-MRS, probably indicating neuronal dysfunction, is associated with interictal spiking in intensive EEG monitoring. Duration of seizure symptoms associated with increased Cr peaks probably reflects increased gliosis.