Memory Tests Distinguish Between Patients with Focal Temporal and Extratemporal Lobe Epilepsy

Abstract

We examined the ability of preoperative memory performance to distinguish between patients who had been diagnosed as having left (LTLE, n = 31), right (RTLE, n = 37), and extra-(ETLE, n = 17) temporal lobe focal epilepsy. All patients eventually underwent surgical resections. Analyses indicated that the ETLE group performed better than the RTLE group on nonverbal memory measures and better than the LTLE group on verbal memory measures. Discriminant function analyses indicated that use of a combination of measures that assess different aspects of memory were of significant value in distinguishing between patients with focal TLE and ETLE. This approach, as compared the use of single measures, improved classification rates of all three groups. The best single predictor of group membership, an index of verbal learning, yielded a 47% overall correct classification rate, with sensitivities ranging from 25 to 59%, and performed at worse than chance levels in classifying RTLE patients. A multivariate approach, which included an index of verbal and nonverbal learning, incidental nonverbal memory, and consolidation of organized and rote verbal material, yielded a 65% correct classification rate, with sensitivities ranging from 57 to 75%. This compares favorably with the other noninvasive techniques for lateralizing epileptogenic lesions.

Correlation between 1H MRS and Memory before and after Surgery in Mesial Temporal Lobe Epilepsy with Hippocampal Sclerosis

“…Verbal and nonverbal memory scores of RTLE patients did not differ after surgery; however, a decrease at verbal memory scores was detected in LTLE patients. This profile is consistent with the studies reporting disorders in material-specific memory in patients with MTLE before and after surgery (17)(18)(19)(20)(21)(22)(23)(24). When NAA/Cho+Cr values are taken into account, the comparison of values demonstrated lower scores both in R and LTLE patients when compared with the same side of the control group (Table 2).…”

Comorbidity of Anxiety and Affective Disorders as Neuropsychiatric and Evolutionary Problem (A New Concept)

“…It implies that nonverbal and visual functions are determined not only by right hemisphere but by left hemisphere too. The similar findings have been also obtained in other studies (Barr& Consortium, 1995;Breier et al, 1996). Notably, the similar results are observed irrespective of epilepsy form, i.e.…”

Impaired hippocampal rhythmogenesis in a mouse model of mesial temporal lobe epilepsy

“…Similar to the distribution in control animals, somata of somatostatin-immunopositive interneurons were primarily found in the stratum oriens, pyramidale, and lucidum of the ventral CA3 area. Quantitative analysis further showed that the density of the interneurons was not reduced in this area in KA-injected animals [440 Ϯ 54 per mm 3 To identify electrophysiological alterations after KA injection, we carried out electroencephalogram recordings from the hippocampus of freely moving control ( Fig. 1 A1 and A2) and epileptic mice ( Fig.…”

“…Memory problems are common in human and animal models of mTLE, but the mechanisms are unclear (2)(3)(4). Several animal models have been developed to investigate the cellular and network mechanisms of epilepsy.…”