Central auditory processing impairment in patients with temporal lobe epilepsy.

In temporal lobe epilepsy (TLE) there may be functional abnormalities or structural lesions that can manifest as a central auditory processing disorder, which is defined as a disorder in the recognition, discrimination, ordering, grouping, and localization of sounds, with emphasis on the processing of nonspeech sounds. We performed frequency pattern, duration pattern, and dichotic tests in 28 patients with TLE with normal hearing on pure tone audiometry. The scores on the frequency pattern, duration pattern, and dichotic tests were abnormal in 78.6, 57.1, and 20.6% of patients, respectively, with no significant differences with the laterality of TLE. Patients with hippocampal sclerosis performed significantly worse than patients with normal MRI findings in frequency tests. Longer duration of epilepsy is negatively correlated with both the duration pattern and dichotic tests (P<0.05). Our results suggest that patients with TLE may be at risk for impairment of central auditory processing, which is increased in patients with hippocampal sclerosis or a longer duration of epilepsy.