Cognitive Impairment in Patients with Temporal Lobe Epilepsy

Research Article

Farhat Nouha, Daoud Sawsan, Sa

Abstract

Objectives: To evaluate the frequency and the type of cognitive impairment (CI) in patients with temporal lobe epilepsy and to determine eventual risk factors for its occurrence. Methods: We have conducted across-sectional study in TLE patients and healthy controls (HC). All of them underwent neuropsychological assessment by using a large battery of tests to detect CI. EEG and Cerebral MRI were performed for all patients. Results: Thirty-two TLE patients and thirty matched HC were enrolled. The mean age of our patients was 35 ± 8.3 yrs. The rate duration of evolution epilepsy until the appearance of CI was 14 ± 10 yrs. In our study, comparative neuropsychological assessment between TLE patients and controls demonstrates that epileptic patients have an impairment of many cognitive processes. The most common CI are: alteration of reaction and processing speed (100% of cases), attention deficit (93.6% of cases), deterioration in verbal episodic memory (87.5% of cases) and visual episodic memory (78.1% of cases). Verbal fluency and working memory are impaired in respectively 3/4 and about half (53.1%) of our patients. At the opposite, executive and visual-spatial functions are rarely affected. Neuropsychological scores worsen with advanced age, long duration of epilepsy, high seizure frequency, clonazepam intake and presence of temporal lesion at cerebral MRI. However, high level of education seems to be protective. TLE patients with lesion evolving the temporal lobe of the dominant hemisphere have had lower scores, especially in tests for verbal memory. At the opposite, when the other side is affected, only the episodic visual memory is impaired. Conclusion: CI is frequent in TLE and alters the quality of patient’s life. We emphasize the importance of periodical neuropsychological assessment to detect early CI and undertake the adequate measures to prevent patient to get worse.

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