azam navaei lavasani

Auditory temporal processing is the main feature of speech processing abilities which including temporal resolution, temporal ordering, temporal integration and temporal masking. Even though the patients with temporal lobe epilepsy have normal hearing, they may show speech recognition disorders. This study aimed to compare the auditory temporal processing in patients with left and right temporal lobe epilepsy. In this cross sectional non-interventional study, 25 patients with Temporal Lobe Epilepsy (TLE) with mean age of 31.1 years including 11 patients with Right Temporal Lobe Epilepsy (RTLE) and 14 patients with Left Temporal Lobe Epilepsy (LTLE) were evaluated by gap in noise (GIN) and duration pattern sequencing (DPS) tests. Results were compared with t-test analysis. There was no significant difference between patients with RTLE and LTLE in GIN test (p>0.05). But there was significant difference between patients with RTLE and LTLE (p=0.000) in DPS test. Patients with temporal lobe epilepsy have difficulties in temporal processing performances. Difficulties are more significant in patients with LTLE since the left temporal lobe is specialized for the processing of temporal information especially for the temporal ordering.

Temporal lobe epilepsy (TLE) is one of the most frequent epileptic syndromes in adults. Some patients with epilepsy، especially TLE، have central auditory disorders، such as temporal processing، even though they have normal peripheral auditory function. The Gaps-in-Noise (GIN) test is one of the new tests for assessing auditory temporal resolution. The aim of this study was to evaluate temporal resolution ability in patients with unilateral temporal lobe epilepsy. In this cross-sectional and descriptive-analytic study، 25 subjects with temporal lobe epilepsy (11 patients with right temporal lobe epilepsy and 14 patients with left temporal lobe epilepsy) and 18 normal control subjects of 15 to 50 years of age were assessed by the GIN test. Parameters of GIN test were analyzed by one-way ANOVA and compared between the three groups. There was a significant difference in the mean of approximate threshold and percentage of correct answer in GIN test in the right ear، left ear، and mean of both ears between patients with temporal lobe epilepsy and normal subjects (p<0. 05). However، difference between right and left temporal lobe epilepsy groups were not significant (p>0. 05). The lower percentage of correct answer and higher approximate threshold in patients with temporal lobe epilepsy in comparison with the normal control group revealed temporal processing deficiencies especially in temporal resolution abilities. This may be due to involvement of structures related to temporal processing.

The effects of brain lesions on the ability to sequence auditory stimuli have been documented in numerous studies. Some investigations have demonstrated that for almost all people، left hemisphere is specialized in temporal processing، especially the temporal ordering. The Aim of this study was to evaluate the temporal processing abilities of patients with unilateral temporal lobe epilepsy by means of “duration pattern sequence«test. In this cross-sectional study، 25 temporal lobe epileptic subjects (11 patients with right temporal lobe epilepsy and 14 ones with left temporal lobe epilepsy) and 18 normal controls with the age range of 15 to 50 years were assessed by duration pattern test. All subjects were evaluated in rehabilitation faculty of Tehran University of Medical Science. The mean scores of correct answers were statistically compared between the three groups using one-way ANOVA. Tukey’s HSD test revealed significant differences between controls and patients with left temporal lobe epilepsy and also between patients with right and those with left temporal lobe epilepsy (P < 0. 05). Difference subjects between right temporal lobe epilepsy and normal groups، however، were not significant (P > 0. 05). Difficulties in processing of temporal ordering among the patients with left temporal lobe epilepsy can be considered as a proof for the specialization of the left temporal lobe in the processing of temporal ordering.