Lenka Krámská

Different Surgical Approaches for Mesial Temporal Epilepsy: Resection Extent, Seizure, and Neuropsychological Outcomes

Background: Surgical therapy of intractable mesial temporal lobe epilepsy (MTLE) is an effective and well-established treatment. Objectives: We compared two different surgical approaches, standard microsurgical anterior temporal resection (ATL) and stereotactic radiofrequency amygdalohippocampectomy (SAHE) for MTLE, with respect to the extent of resection or destruction, clinical outcomes, and complications. Material and Methods: 75 MTLE patients were included: 41 treated by SAHE (11 right sided, 30 left sided) and 34 treated by ATL (21 right sided, 13 left sided). Results: SAHE and ATL seizure control were comparable (Engel I in 75.6 and 76.5% 2 years after surgery and 79.3 and 76.5% 5 years after procedures, respectively). The neuropsychological results of SAHE patients were better than in ATL. In SAHE patients, no memory deficit was found. Hippocampal (60.6 ± 18.7%) and amygdalar (50.3 ± 21.9%) volume reduction by SAHE was significantly lower than by ATL (86.0 ± 12.7% and 80.2 ± 20.9%, respectively). The overall rate of surgical nonsilent complications without permanent neurological deficit after ATL was 11.8%, and another 8.8% silent infarctions were found on MRI. The rate of clinically manifest complications after SAHE was 4.9%. The rate of visual field defects after SAHE was expectably less frequent than after ATL. Conclusion: Seizure control by SAHE was comparable to ATL. However, SAHE was safer with better neuropsychological results.

Stereotactic radiofrequency amygdalohippocampectomy: Two years of good neuropsychological outcomes

PURPOSE To provide two-year seizure and neuropsychological outcomes in patients treated by stereotactic radiofrequency amygdalohippocampectomy (SAHE), an alternative, minimally invasive method for the treatment of mesial temporal lobe epilepsy (MTLE). MATERIAL AND METHODS Thirty-seven MTLE patients treated by SAHE (26 left-sided, 11 right-sided) were included. Patients underwent neuropsychological evaluation by the Wechsler Adult Intelligence Scale-Revised and the Wechsler Memory Scale-Revised preoperatively, 1 year and 2 years after SAHE. RESULTS Two years after SAHE twenty-eight (75.5%) patients were assessed as Engel Class I and seven (18.9%) patients as Engel Class II. In two patients (5.4%) treatment failed, one of them was classified as Class III and one as Class IV. Irrespective of the laterality of the procedure, the group improved significantly in Global and Verbal Memory Quotients, Attention, Delayed Recall, Semantic Long-term memory subtest and Working Memory. Additionally, increases in Full-scale, Verbal and Visual Intelligence Quotients were detected on the group level. CONCLUSION In the present study we report good seizure control and neuropsychological outcomes after SAHE in our patients. We hypothesize that good neuropsychological results were achieved by the incomplete destruction of target structures, sparing the lateral temporal neocortex, and also partially by practice effect. Treatment failures in seizure control may be attributed to larger epileptogenic zones.

Stereotactic radiofrequency amygdalohippocampectomy for the treatment of temporal lobe epilepsy: do good neuropsychological and seizure outcomes correlate with hippocampal volume reduction?

Temporal lobe surgery bears the risk of a decline of neuropsychological functions. Stereotactic radiofrequency amygdalohippocampectomy (SAHE) represents an alternative to mesial temporal lobe epilepsy (MTLE) surgery. This study compared neuropsychological results with MRI volumetry of the residual hippocampus. We included 35 patients with drug-resistant MTLE treated by SAHE. MRI volumetry and neuropsychological examinations were performed before and 1 year after SAHE. Each year after SAHE clinical seizure outcome was assessed. One year after SAHE 77% of patients were assessed as Engel Class I, 14% of patients was classified as Engel II and in 9% of patients treatment failed. Two years after SAHE 76% of subjects were classified as Engel Class I, 15% of patients was assessed as Engel II and in 9% of patients treatment failed. Hippocampal volume reduction was 58±17% on the left and 54 ± 27% on the right side. One year after SAHE, intelligence quotients of treated patients increased. Patients showed significant improvement in verbal memory (p=0.039) and the semantic long-term memory subtest (LTM) (p=0.003). Patients treated on the right side improved in verbal memory, delayed recall and LTM. No changes in memory were found in patients treated on the left side. There was a trend between the larger extent of the hippocampal reduction and improvement in visual memory in speech-side operated.

Cognitive outcome after stereotactic amygdalohippocampectomy

PURPOSE We sought to determine the neuropsychological outcome after stereotactic radiofrequency amygdalohippocampectomy performed for intractable mesial temporal lobe epilepsy. METHODS The article describes the cases of 31 patients who were evaluated using the Wechsler Adult Intelligence Scale-Revised and the Wechsler Memory Scale-Revised prior to, and one year after, surgery. KEY FINDINGS Patients showed increases in their mean Full Scale, Verbal and Performance IQ scores of 4, 3 and 4 IQ points respectively (p<.05). 5 (17.2%), 4 (13.8%) and 4 (13.3%) patients improved in their Full-scale, Verbal and Performance IQ respectively. No significant changes were found in memory performance - with a mean increase of 1, 3 and 0 MQ points in Global, Verbal and Visual memory respectively (p<.05). Global memory improved in 3 (10.3%) patients, verbal memory in 1 (3.4%) and 1 patient (3.3%) showed deterioration in visual memory. SIGNIFICANCE Our results provide evidence for unchanged memory in patients with MTLE after the procedure. No verbal memory deterioration was detected in any of our patients, while improvements were found in intellectual performance. The results suggest that stereotactic radiofrequency amygdalahippocampectomy could be superior to open surgery in terms of its neurocognitive outcomes. A larger randomised trial of these approaches is justified.

MRI-guided stereotactic amygdalohippocampectomy: a single center experience

Background This paper presents our experience of stereotactic radiofrequency amygdalohippocampectomy performed for intractable mesial temporal lobe epilepsy. Methods The article describes the cases of 61 patients who were treated during the period from 2004 to 2010. Mean postoperative follow-up was 5.3 years. Neuropsychological results were obtained for a subset of 31 patients. Results At their last postsurgical visit, 43 (70.5%) patients were Engel class I, six (9.8%) class II, nine (14.8%) class III, and three (4.9%) class IV. The surgery was complicated by four intracranial hematomas. One of them caused acute hydrocephalus and was treated by shunting and resolved without sequelae, while another caused transitory aphasia. The remaining hematomas were asymptomatic. There were two cases of meningitis which required antibiotic treatment. One patient committed suicide due to postoperative depression. After the procedure, we performed open epilepsy surgery and rethermolesions in three and two patients, respectively (8.2%). Patients showed increases in their mean full scale, verbal, and performance intelligence quotient (IQ) scores of 4, 3, and 4 IQ points, respectively (P<0.05). Five (17.2%), four (13.8%), and four (13.3%) patients improved their full scale, verbal, and performance IQ scores, respectively. No significant changes were found in memory performance, with a mean increase of 1, 3, and 0 memory quotient points in global, verbal, and visual memory, respectively (P<0.05). Global memory improved in three (10.3%) patients, verbal memory in one (3.4%), and one patient (3.3%) showed deterioration in visual memory. Conclusion Stereotactic radiofrequency amygdalohippocampectomy offers a safe, effective, and less aggressive treatment modality in cases of well-defined mesial temporal lobe epilepsy. Seizure outcome is comparable with the results of conventional epilepsy surgery and cognitive results could be even better.

Relationship between remnant hippocampus and amygdala and memory outcomes after stereotactic surgery for mesial temporal lobe epilepsy.

Background and purpose Mesial temporal structures play an important role in human memory. In mesial temporal lobe epilepsy (MTLE), seizure activity is generated from the same structures. Surgery is the definitive treatment for medically intractable MTLE. In addition to standard temporal lobe microsurgical resection, stereotactic radiofrequency amygdalohippocampectomy (SAHE) is used as an alternative MTLE treatment. While memory impairments after standard epilepsy surgery are well known, it has been shown that memory decline is not a feature of SAHE. The aim of the present study was to correlate the volume of the remnant hippocampus and amygdala in patients treated by SAHE with changes in memory parameters. Materials and methods Thirty-seven MTLE patients treated by SAHE (ten right, 27 left) were included. Patients underwent magnetic resonance imaging examinations including hippocampal and amygdalar volumetry and neuropsychological evaluation preoperatively and 1 year after surgery. Results Using Spearman correlation analyses, larger left-sided hippocampal reductions were associated with lower verbal memory performance (ρ=−0.46; P=0.02). On the contrary, improvement of global memory quotient (MQ) was positively correlated with larger right-sided hippocampal reduction (ρ=0.66; P=0.04). Similarly, positive correlations between the extent of right amygdalar reduction and verbal MQ (ρ=0.74; P=0.02) and global MQ change (ρ=0.69; P=0.03) were found. Thus, larger right hippocampal and amygdalar reduction was associated with higher global and verbal MQ change after SAHE. Conclusion Larger left-sided hippocampal reductions were associated with lower verbal memory performance. This finding is in accordance with the material-specific model of human memory, which states that the dominant hemisphere is specialized for the learning and recall of verbal information. We hypothesize that larger right-sided ablations enable the left temporal lobe to support memory more effectively, perhaps as a consequence of epileptiform discharges spreading from remnants of right mesiotemporal structures to the left.

Five-Year Neuropsychological Outcome after Stereotactic Radiofrequency Amygdalohippocampectomy for Mesial Temporal Lobe Epilepsy: Longitudinal Study

Purpose: To assess the neuropsychological performance recoded over a period of 5 years after stereotactic radiofrequency amygdalohippocampectomy (SAHE) in the treatment of mesial temporal lobe epilepsy. Material and Methods: Thirty patients (mean age 38 years, 14 females/16 males) were included in this study. Twenty-one patients were treated on the left side, 9 on the right. Patients underwent neuropsychological evaluation by the Wechsler Adult Intelligence Scale-Revised and the Wechsler Memory Scale-Revised preoperatively and 5 years after SAHE. Results: Twenty-three (77%) patients were classified as Engel class I. At the group level, we found significant increases in all intelligence domains (Global, Visual, and Performance) by 19.1 (7.4), 15.8 (6.1), and 19.1 (7.9) points, respectively. Significant improvements were also detected in all memory measures (Global, Verbal, Visual, Attention/Concentration, Delayed Recall) by 19.4 (14.2), 16.9 (13.3), 19.0 (14.7), 15.3 (15.0), and 24.6 (13.4), respectively. Patients with left-sided surgery improved significantly more in Attention/Concentration. Otherwise, there were no statistically significant differences in memory function improvements between subgroups according to the operated side. Conclusion: After SAHE, we found favorable long-term neuropsychological outcomes. These results could be caused by incomplete destruction of target structures and minimization of collateral damage that possibly enables adaptive postoperative neuronal reorganization.

A neuropsychologist’s view: Outcome after RF-ablation for mTLE

Concern about postoperative worsening of cognitive functions after temporal lobe epilepsy surgery is an important issue. In this article we review our data on neuropsychological outcome after radiofrequency (RF) ablation of amygdalohippocampal complex (AHC). On a group level we found initial improvement in intelligence domains and unchanged memory scores one year after the surgery. During longitudinal follow-up, we found improvement in both intellectual and memory domains. This improvement was most pronounced up to two years after surgery. On an individual level, no patient worsened in any intellectual domain and most patients improved in memory. We hypothesize that this favorable outcome may be a consequence of minimization of collateral damage and incomplete destruction of target structures. We also summarize our experience with psychiatric complications of the procedure.