Untersuchung des deklarativen Gedächtnisses für Public Events bei Patienten mit Temporallappenepilepsie

Introduction Temporal lobe epilepsy is one of the most frequent focal epilepsies. Multiple causes of this disease are discussed. It is well-known that patients with chronic epilepsy over many years, especially temporal lobe epilepsy, frequently complain about memory deficits. In particular episodic memory contents, such as memories of public events, seem to be affected. This supports the hypothesis that the temporal lobe and particularly the hippocampus plays a crucial role for an intact memory function. With this investigation we evaluated, with help of a standardized questionnaire for public events, whether patients with temporal lobe epilepsy show a restriction of short term memory and whether this is associated with the first occurrence of seizures. Material and Methods At the beginning of the investigation a standardized comprehensive questionnaire with 100 items was developed. This consisted of public events of different categories for the years 1960-2004. With help of this interview questionnaire the memory of 20 patients with temporal lobe epilepsy and 20 comparable, healthy control persons was tested. All participants were asked about events themselves, their chronology and the subjective emotional validation of the events. Results The patients with temporal lobe epilepsy versus controls did not differ significantly concerning age, sex, training, handedness and intelligence. However significant differences resulted in favor of the healthy control persons regarding total average capacity of memory and the capacity during the individual time decades. Here main effects for the group and decade, as well as an interaction effect for group and decade, resulted. Significant differences concerning the chronology and their subjective emotional validation of the events did not result. Also differences according to side localization of the epilepsy could not be found. Additionally, for patients with hippocampal sclerosis a significant difference between the capacities of memory before and after onset of epilepsy, as well as a lower subjective emotional validation of the events for right-sided patients could be detected. Discussion: On the basis of this investigation it could be shown that patients with chronic temporal lobe epilepsy have a significantly worse capacity of memory concerning public events than healthy control persons. The genesis in particular of the existence of a right-sided hippocampus sclerosis seems to play therefore an important role. Further differences between right and left-sided temporal lobe epilepsy were not evaluated. On the basis of this investigation a clear effect of the illness duration could not be proven. In addition no deficiency in normal memory chronology could be detected. Collectively these results suggest that testing specific memory achievements, such as public events, could be used in clinical practice for optimizing the collection of illness-specific neuropsychological deficiencies and localization of unclear epileptic syndromes.