Surgical outcome of temporal plus epilepsy is improved by multilobar resection

A survey of the prevalence and patterns of neuropsychological assessment practices across epilepsy surgery centers in India: Toward establishing a national guideline

Neuropsychology plays an important role in optimizing epilepsy management, but there are no practice guidelines for low- and middle-income countries with emerging services. The National Epilepsy Surgery Support Activity Network (NESSAN), a national working group that supports and optimizes epilepsy surgery programs in India, explored the present status of pre- and post epilepsy surgery neuropsychological assessment practices across India as an initial step in developing national evidence-based test guidelines. An online survey was conducted using two questionnaires, one for neurologists and the second for neuropsychologists and speech-language pathologists working in epilepsy surgery centers. The questions to neurologists covered the setting, description, and nature of the neuropsychology services provided for adults and children as part of the epilepsy surgery program, and their perceptions about the importance and indications for neuropsychological assessment in epilepsy surgery. The questions to neuropsychologists inquired about their qualifications and training, pre- and postsurgical assessment procedures, and domain-specific cognitive tests and scales for mood, quality of life, and language evaluations. Forty-three centers responded, and neuropsychology services were available at three fourth of the centers, but a dedicated full-time neuropsychologist was available in only 16% of centers. Ninety percent of the neurologists considered neuropsychological evaluation an indispensable part of presurgical evaluation. However, only a few of them believed that the results influenced their decision about the extent of resection and ruling against surgery. The survey found considerable heterogeneity in terms of qualifications and training of neuropsychologists, evaluation procedures, test protocols, and normative data that will need to be harmonized to ensure uniform practice across the country. We believe that the results from this survey provide a road map for implementing measures to minimize existing inadequacies and harmonize neuropsychology services in India and as well as in other countries with emerging neuropsychology services. PLAIN LANGUAGE SUMMARY: Neuropsychological assessment is an integral part of the pre- and post epilepsy surgery evaluations. In India, the National Epilepsy Surgery Support Activity Network (NESSAN), a body of multidisciplinary professionals, conducted a survey to examine existing neuropsychology practices. The responses from 43 centers across the country revealed considerable heterogeneity in tests and few trained and qualified neuropsychologists. In low- and middle-income countries (LMIC) with emerging neuropsychology services, there is a need to have uniform test protocols, specialized training, and guidelines for optimizing neuropsychology services across all the epilepsy surgery centers.

Outcome of Epilepsy Surgery in MRI-Negative Patients Without Histopathologic Abnormalities in the Resected Tissue

BACKGROUND AND OBJECTIVE

Patients with presumed nonlesional focal epilepsy-based on either MRI or histopathologic findings-have a lower success rate of epilepsy surgery compared with lesional patients. In this study, we aimed to characterize a large group of patients with focal epilepsy who underwent epilepsy surgery despite a normal MRI and had no lesion on histopathology. Determinants of their postoperative seizure outcomes were further studied.

METHODS

We designed an observational multicenter cohort study of MRI-negative and histopathology-negative patients who were derived from the European Epilepsy Brain Bank and underwent epilepsy surgery between 2000 and 2012 in 34 epilepsy surgery centers within Europe. We collected data on clinical characteristics, presurgical assessment, including genetic testing, surgery characteristics, postoperative outcome, and treatment regimen.

RESULTS

Of the 217 included patients, 40% were seizure-free (Engel I) 2 years after surgery and one-third of patients remained seizure-free after 5 years. Temporal lobe surgery (adjusted odds ratio [AOR]: 2.62; 95% CI 1.19-5.76), shorter epilepsy duration (AOR for duration: 0.94; 95% CI 0.89-0.99), and completely normal histopathologic findings-versus nonspecific reactive gliosis-(AOR: 4.69; 95% CI 1.79-11.27) were significantly associated with favorable seizure outcome at 2 years after surgery. Of patients who underwent invasive monitoring, only 35% reached seizure freedom at 2 years. Patients with parietal lobe resections had lowest seizure freedom rates (12.5%). Among temporal lobe surgery patients, there was a trend toward favorable outcome if hippocampectomy was part of the resection strategy (OR: 2.94; 95% CI 0.98-8.80). Genetic testing was only sporadically performed.

DISCUSSION

This study shows that seizure freedom can be reached in 40% of nonlesional patients with both normal MRI and histopathology findings. In particular, nonlesional temporal lobe epilepsy should be regarded as a relatively favorable group, with almost half of patients achieving seizure freedom at 2 years after surgery-even more if the hippocampus is resected-compared with only 1 in 5 nonlesional patients who underwent extratemporal surgery. Patients with an electroclinically identified focus, who are nonlesional, will be a promising group for advanced molecular-genetic analysis of brain tissue specimens to identify new brain somatic epilepsy genes or epilepsy-associated molecular pathways.

The Value of Stereo-electroencephalography in Temporal Lobe Epilepsy: Huashan Experience

Temporal lobe epilepsy (TLE) is one of the most common drug-refractory epilepsies. However, the diagnosis and treatment of TLE may be improved by better understanding its complex network. In this article, the authors summarize their experience with TLE and discuss their process for using stereo-electroencephalography (SEEG) as part of presurgical evaluation in the past 10 years. The authors demonstrate the value of SEEG in different types of TLE and discuss how their findings have impacted treatment options. Ultimately, the authors' experience will help other centers in addressing TLE cases.

Extended follow-up after anterior temporal lobectomy demonstrates seizure recurrence 20+ years postsurgery

OBJECTIVE

Anterior temporal lobectomy (ATL) for medication-resistant localized epilepsy results in ablation or reduction of seizures for most patients. However, some individuals who attain an initial extended period of postsurgical seizure freedom will experience a later seizure recurrence. In this study, we examined the prevalence and some risk factors for late recurrence in an ATL cohort with extensive regular follow-up.

METHODS

Included were 449 patients who underwent ATL at Austin Health, Australia, from 1978 to 2008. Postsurgical follow-up was undertaken 2-3 yearly. Seizure recurrence was tested using Kaplan-Meier analysis, log-rank test, and Cox regression. Late recurrence was qualified as a first disabling seizure >2 years postsurgery. We examined risks within the ATL cohort according to broad pathology groups and tested whether late recurrence differed for the ATL cohort compared to patients who had resections outside the temporal lobe (n = 98).

RESULTS

Median post-ATL follow-up was 22 years (range = .1-38.6), 6% were lost to follow-up, and 12% had died. Probabilities for remaining completely seizure-free after surgery were 51% (95% confidence interval [CI] = 53-63) at 2 postoperative years, 36% (95% CI = 32-41) at 10 years, 32% (95% CI = 27-36) at 20 years, and 30% (95% CI = 25-34) at 25 years. Recurrences were reported up to 23 years postoperatively. Late seizures occurred in all major ATL pathology groups, with increased risk in the "normal" and "distant lesion" groups (p ≤ .03). Comparison between the ATL cohort and patients who underwent extratemporal resection demonstrated similar patterns of late recurrence (p = .74).

SIGNIFICANCE

Some first recurrences were very late, reported decades after ATL. Late recurrences were not unique to any broad ATL pathology group and did not differ according to whether resections were ATL or extratemporal. Reports of these events by patients with residual pathology suggest that potentially epileptogenic abnormalities outside the area of resection may be implicated as one of several possible underlying mechanisms.