Background: Temporal lobe epilepsy (TLE) is the most common focal type of epilepsy that originates near the auditory cortex and hence may impair auditory cortical processing. The functional integrity of the auditory cortex could be assessed electrophysiologically using slow cortical response (SCR).
Objective: The current study was designed to predict the validity of SCR in evaluating central auditory processing (CAP) in TLE.
Subjects and Methods:This observational, case-control study involved 38 right-handed participants; the TLE group included 19 right-handed patients (International League Against Epilepsy criteria was used for diagnosis), and the control group included 19 right-handed adults matching the TLE group in both gender and age.
Results: TLE group exhibited a significant delay of the left ear's N1 and P2 latency and a significant reduction of the N1P2 complex amplitude (in both ears). The effect of different variables revealed negative correlations between SCR latencies and each of the age, age of onset of TLE, and time of last seizure; positive correlations between SCR amplitudes and each of the age, age of onset of TLE, and time of last seizure; a significant effect of gender on P2 and N2 latencies; and a significant effect of seizure frequency on P1 latency. Validity measures and the ROC curve revealed a better accuracy for the left ear's N1 (82%) and then P2 (73%) latencies and for the N1P2 amplitude (right=81% and left=76%).
Conclusions: The current results indicate altered neural activities within the temporal lobes of patients with TLE, which can be documented electrophysiologically by SCR. N1 and P2 waves' measures showed the highest accuracy, hence providing useful information about possible functional deterioration and impaired CAP in this population.