Role of dentate gyrus alterations in mesial temporal sclerosis.

Drug-resistant chronic temporal lobe epilepsy is the most common type of epilepsy that undergoes surgical treatment. To verify if dentate gyrus alterations may play a role in patients with mesial temporal sclerosis (MTS), 14 patients, submitted to epilepsy surgery, were selected. Only cases with MTS alone were included. Granule cell dispersion (GCD) was observed in 7 cases (50%). A statistically significant correlation between GCD and the mean number of seizures/month was evidenced. The percentage of patients who did not achieve seizure relief (i.e. they were not in Engel class 1A) was 57.14% in patients without GCD, whereas that percentage dropped to 14.29% in patients with GCD. The association between a more favorable postsurgical epileptogenic outcome and granule cell pathology in patients with MTS has been observed, thus suggesting that dentate gyrus alterations may play a role in drug-resistant TLE.