Abstract

Assessment of memory has been an integral part in the diagnosis and treatment of temporal lobe epilepsy(TLE). In this context our reviews are focused on the following three issues. The first issue involves the pattern of memory impairment in the TLE. Memory decline in TLE is assumed to show the 'material-specific impairment(MSI)', but studies over two decades have proven only the half of the hypothesis. Verbal memory impairments in left TLE were consistently supported, but visuospatial memory impairment in right TLE were not. According to our analysis, a possible cause of mixed results may be attributed to the characteristics of visuospatial memory tasks. Visual memory can be divided into object memory and position memory component, and most of the studies which failed to show impairment in right TLE used the task in which the former component were emphasized. In contrast, studies with the task of the latter component differentiated the right TLE successfully. Utilizing the tasks in which position memory is emphasized, future researchers may attempt to prove the remaining half of MSI hypothesis and to increase the sensitivity of lateralization through memory assessment. The second issue discusses memory change following temporal lobectomy(TL). The patterns of change are assumed to show material-specific decline, but only the half of this hypothesis was proven. Further research efforts should be focused on change of not only ipsilateral but also contralateral memory function to TL side. Finally, variables predicting the prognosis of memory were reviewed. Factors such as preoperative memory function, onset of seizure, degree of seizure relief, severity of hippocampal atrophy, gender of the patients may mediate the pattern of memory change. In the future it is necessary to investigate various prognostic factors of memory outcome in integrated framework.