Cognitive features and surgical outcome of patients with long-term epilepsy-associated tumors (LEATs) within the temporal lobe.

OBJECTIVE: The objective of the study was to evaluate cognitive and epilepsy-related features in 166 surgically treated patients with epilepsy with long-term epilepsy-associated tumors (LEATs) located in the temporal lobe. METHOD: Pre- and postsurgical cognitive as well as the one-year seizure outcome of adult patients with histopathologically confirmed LEATs (28 grade-I dysembryoplastic neuroepithelial tumors (DNET), 95 grade-I gangliogliomas (GG), 24 grade-I pilocytic astrocytomas (PA), 9 grade-II pleomorphic xanthoastrocytoma (PXA), 10 grade-II diffuse astrocytoma (DA)) who underwent epilepsy surgery in Bonn/Germany between 1988 and 2012 were evaluated. RESULTS: At baseline, tumor groups differed in regard to age at epilepsy onset and location within the temporal lobe. Postoperative seizure freedom was achieved most frequently (>77.8%) in DNET, GG, and DA, less often in PXA (62.5%) and the least in PA (56.5%). Preoperative memory was impaired in 67.1% of all patients, executive functions in 44.7%, and language in 45.5%. Patients with PA displayed the poorest cognitive performance. Individual significant memory decline that was observed in 27.1% of all patients was predicted by left-sided surgery, a mesial pathology, and extended hippocampal resection. Executive functions depended on antiepileptic drug (AED) load and remained stable (72.0%) or even improved (21.6%) after surgery. Language functions were unchanged in 89.5% of patients. CONCLUSION: Patients with LEATs in the temporal lobe frequently show cognitive impairments. Predictors for pre- and postoperative cognition mostly correspond to what is known for temporal lobe epilepsy and resections in general. However, different tumor types appear to be associated with different cognitive and seizure outcomes with astrocytoma as the least benefitted group.

Current use of imaging and electromagnetic source localization procedures in epilepsy surgery centers across Europe.

OBJECTIVE: In 2014 the European Union-funded E-PILEPSY project was launched to improve awareness of, and accessibility to, epilepsy surgery across Europe. We aimed to investigate the current use of neuroimaging, electromagnetic source localization, and imaging postprocessing procedures in participating centers. METHODS: A survey on the clinical use of imaging, electromagnetic source localization, and postprocessing methods in epilepsy surgery candidates was distributed among the 25 centers of the consortium. A descriptive analysis was performed, and results were compared to existing guidelines and recommendations. RESULTS: Response rate was 96%. Standard epilepsy magnetic resonance imaging (MRI) protocols are acquired at 3 Tesla by 15 centers and at 1.5 Tesla by 9 centers. Three centers perform 3T MRI only if indicated. Twenty-six different MRI sequences were reported. Six centers follow all guideline-recommended MRI sequences with the proposed slice orientation and slice thickness or voxel size. Additional sequences are used by 22 centers. MRI postprocessing methods are used in 16 centers. Interictal positron emission tomography (PET) is available in 22 centers; all using 18F-fluorodeoxyglucose (FDG). Seventeen centers perform PET postprocessing. Single-photon emission computed tomography (SPECT) is used by 19 centers, of which 15 perform postprocessing. Four centers perform neither PET nor SPECT in children. Seven centers apply magnetoencephalography (MEG) source localization, and nine apply electroencephalography (EEG) source localization. Fourteen combinations of inverse methods and volume conduction models are used. SIGNIFICANCE: We report a large variation in the presurgical diagnostic workup among epilepsy surgery centers across Europe. This diversity underscores the need for high-quality systematic reviews, evidence-based recommendations, and harmonization of available diagnostic presurgical methods.

Neuropsychological outcome after epilepsy surgery in patients with bilateral Ammon's horn sclerosis.

OBJECT: The purpose of this study was to retrospectively assess the objective and subjective neuropsychological outcome after epilepsy surgery in patients with bilateral Ammon's horn sclerosis (AHS). METHODS: Memory and executive functions were evaluated at baseline and at follow-up in 11 surgically treated patients and compared with 8 pharmacologically treated patients with temporal lobe epilepsy and bilateral AHS. The median follow-up duration was 16 months in the surgically treated patients and 80.5 months in the pharmacologically treated group. Subjective outcome was evaluated by questionnaires and included mood, quality of life, subjective memory, and activities of daily living. RESULTS: At the follow-up assessment, 82% of the surgically treated patients as opposed to 0% of the nonsurgery patients were seizure free. In the surgical group, nonverbal memory performance did not change significantly in any patient after surgery, but there was a floor effect in 55% of the surgical patients. Regarding verbal memory, 9% of the surgical patients improved while 73% declined, despite severe impairments already evident at baseline. In the nonsurgery control group, 13% of the patients declined in nonverbal memory (floor effect in 63%) and 25% declined in verbal memory (floor effect in 25%) at follow-up. None of the controls improved at follow-up. Executive functions remained unchanged on an impaired level in both groups. At follow-up, the patient groups did not differ significantly with respect to mood, quality of life, subjective memory, or activities of daily living. However, in most aspects, surgically treated patients reported a slightly better subjective outcome than pharmacologically treated patients and a significantly improved quality of life. CONCLUSIONS: These results suggest that beyond benefits concerning seizure control, surgically treated patients with bilateral AHS, despite already poor baseline performance, are still at risk for severe postoperative decline in memory. In the light of predominantly minor benefits on a subjective level, the findings put the overall outcome of epilepsy surgery in bilateral AHS patients into perspective.