Strategies for surgical treatment of epilepsies in developing countries

Automatic detection of epilepsy from EEGs using a temporal convolutional network with a self-attention layer

BACKGROUND

Over 60% of epilepsy patients globally are children, whose early diagnosis and treatment are critical for their development and can substantially reduce the disease's burden on both families and society. Numerous algorithms for automated epilepsy detection from EEGs have been proposed. Yet, the occurrence of epileptic seizures during an EEG exam cannot always be guaranteed in clinical practice. Models that exclusively use seizure EEGs for detection risk artificially enhanced performance metrics. Therefore, there is a pressing need for a universally applicable model that can perform automatic epilepsy detection in a variety of complex real-world scenarios.

METHOD

To address this problem, we have devised a novel technique employing a temporal convolutional neural network with self-attention (TCN-SA). Our model comprises two primary components: a TCN for extracting time-variant features from EEG signals, followed by a self-attention (SA) layer that assigns importance to these features. By focusing on key features, our model achieves heightened classification accuracy for epilepsy detection.

RESULTS

The efficacy of our model was validated on a pediatric epilepsy dataset we collected and on the Bonn dataset, attaining accuracies of 95.50% on our dataset, and 97.37% (A v. E), and 93.50% (B vs E), respectively. When compared with other deep learning architectures (temporal convolutional neural network, self-attention network, and standardized convolutional neural network) using the same datasets, our TCN-SA model demonstrated superior performance in the automated detection of epilepsy.

CONCLUSION

The proven effectiveness of the TCN-SA approach substantiates its potential as a valuable tool for the automated detection of epilepsy, offering significant benefits in diverse and complex real-world clinical settings.

The Pediatric Epilepsy Surgery Interest Group (PESIG) under the auspice of the ISPN Research Committee: Availability of relevant technology and geographical distribution

PURPOSE

Epilepsy surgery for pediatric drug-resistant epilepsy has been shown to improve seizure control, enhance patient and family QoL, and reduce mortality. However, diagnostic tools and surgical capacity are less accessible worldwide. The International Society Pediatric Neurosurgery (ISPN) has established a Pediatric Epilepsy Surgery Interest Group (PESIG), aiming to enhance global collaboration in research and educational aspects. The goals of this manuscript are to introduce PESIG and analyze geographical differences of epilepsy surgery and technology availability.

METHODS

PESIG was established (2022) following an ISPN executive board decision. Using a standardized form, we surveyed the PESIG members, collecting and analyzing data regarding geographical distribution, and availability of various epilepsy treatment-related technologies.

RESULTS

Two hundred eighty-two members registered in PESIG from 70 countries, over 6 continents, were included. We categorized the countries by GDP as follows: low, lower-medium, upper-medium, and high income. The most commonly available technology was vagus nerve stimulation 68%. Stereoelectroencephalography was available for 58%. North America had statistically significant greater availability compared to other continents. Europe had greater availability compared to Africa, Asia, and South (Latin) America. Asia had greater availability compared to Africa. High-income countries had statistically significant greater availability compared to other income groups; there was no significant difference between the other income-level subgroups.

CONCLUSION

There is a clear discrepancy between countries and continents regarding access to epilepsy surgery technologies. This strengthens the need for collaboration between neurologists and neurosurgeons from around the world, to enhance medical education and training, as well as to increase technological availability.

Is intraoperative electrocorticography (ECoG) for long-term epilepsy-associated tumors (LEATs) more useful in children?-A Randomized Controlled Trial

OBJECTIVES

The utility of intraoperative electrocorticography (ECoG)-guided resective surgery for pediatric long-term epilepsy-associated tumors (LEATs) with antiseizure medication (ASM) resistant epilepsy is not supported by robust evidence. As epilepsy networks and their ramifications are different in children from those in adults, the impact of intraoperative ECoG-based tailored resections in predicting prognosis and influencing outcomes may also differ. We evaluated this hypothesis by comparing the outcomes of resections with and without the use of ECoG in children and adults by a randomized study.

METHODS

From June 2020 to January 2022, 42 patients (17 children and 25 adults) with LEATs and antiseizure medication (ASM)-resistant epilepsy were randomly assigned to one of the 2 groups (ECoG or no ECoG), prior to surgical resection. The 'no ECoG' arm underwent gross total lesion resection (GTR) without ECoG guidance and the ECoG arm underwent GTR with ECoG guidance and further additional tailored resections, as necessary. Factors evaluated were tumor location, size, lateralization, seizure duration, preoperative antiepileptic drug therapy, pre- and postresection ECoG patterns and tumor histology. Postoperative Engel score and adverse event rates were compared in the pediatric and adult groups of both arms. Eloquent cortex lesions and re-explorations were excluded to avoid confounders.

RESULTS

Forty-two patients were included in the study of which 17 patients were in the pediatric cohort (age < 18 years) and 25 in the adult cohort. The mean age in the pediatric group was 11.11 years (SD 4.72) and in the adult group was 29.56 years (SD 9.29). The mean duration of epilepsy was 9.7 years (SD 4.8) in the pediatric group and 10.96 (SD 8.8) in the adult group. The ECoG arm of LEAT resections had 23 patients (9 children and 14 adults) and the non-ECoG arm had 19 patients (8 children and 11 adults). Three children and 3 adults from the ECoG group further underwent ECoG-guided tailored resections (average 1.33 additional tailored resections/per patient.).The histology of the tailored resection specimen was unremarkable in 3/6 (50%).Overall, the commonest histology in both groups was ganglioglioma and the temporal lobe, the commonest site of the lesion. 88.23% of pediatric cases (n = 15/17) had an excellent outcome (Engel Ia) following resection, compared to 84% of adult cases (n = 21/25) at a mean duration of follow-up of 25.76 months in children and 26.72 months in adults (p = 0.405).There was no significant difference in seizure outcomes between the ECoG and no ECoG groups both in children and adults, respectively (p > 0.05). Additional tailored resection did not offer any seizure outcome benefit when compared to the non-tailored resections.

CONCLUSIONS

The use of intraoperative electrocorticography in LEATs did not contribute to postoperative seizure outcome benefit in children and adults. No additional advantage or utility was offered by ECoG in children when compared to its use in adults. ECoG-guided additional tailored resections did not offer any additional seizure outcome benefit both in children and adults.

How to successfully establish an epilepsy care center in resource-limited countries: A scoping systematic review

PURPOSE

The aim of the current study was to systematically review the literature on establishing epilepsy care centers in resource-limited nations in the world and to provide a comprehensive roadmap on this significantly needed endeavor. This work may provide guidance on how to develop an epilepsy care center in other resource-limited places in the world.

METHODS

Web of science, Science Direct, and MEDLINE (accessed from PubMed) from inception to March 2023 were systematically searched for relevant published manuscripts. In all electronic databases, the following search strategy was implemented and these key words were used (title/abstract): epilepsy AND resource. The inclusion criteria were all original studies and articles written in English.

RESULTS

We could identify nine manuscripts on how to successfully establish an epilepsy care center in resource-limited countries. Two models were identified for such an endeavor: developing a team of trained healthcare professionals (e.g., in Iran, India, China, Vietnam) or a twin affiliation between an advanced epilepsy surgery program in a developed country and a starting program in a developing country (e.g., in Georgia, Tunisia).

CONCLUSION

In order to successfully establish an epilepsy care center in resource-limited countries four pillars are needed: presence of skillful healthcare professionals, having access to basic investigative technologies (i.e., MRI and EEG), a careful planning, and raising awareness.

Resource utilization in management of spontaneous intracerebral hemorrhage without systemic risk factors. Does early surgical decompression matter?

BACKGROUND

Even though different subtypes of spontaneous ICH are frequently linked to a poor prognosis, their causes, pathological features, and prognoses vary. Atypical intracerebral hemorrhage is the subtype of spontaneous ICH that usually occurs due to an underlying localized vascular lesion. It is unrelated to systemic vascular risk factors, mostly affects children and young adults and is associated with a relatively good outcome. This fact should be considered when planning the evaluation and treatment. Investigating the cause of this subtype is fundamental to providing optimal management. However, if resources do not allow completing the investigations, the cause will be more difficult to discover. Treatment decisions will be made under stress to save the patient's life, especially with rapidly deteriorating patients.

METHODS

We described three cases of spontaneous ICH without systemic risk factors where the bleeding source could not be determined before surgery due to a lack of resources, preventing preoperative vascular investigation. Knowing that the atypical ICH has a distinct identity, regarding etiology and prognosis, encouraged the surgeons to resort to early surgical decompression as an alternative plan. We reviewed the literature searching for supporting evidence.

RESULTS

The results of treatment of the presented cases were satisfactory. The lack of reported similar cases was brought to light by a literature analysis that sought to provide backing for the proposed management strategy. In the end, we supplied two graphic organizers to help readers remember the different types and treatment of hemorrhagic stroke.

CONCLUSION

There isn't enough evidence to show that there are other ways to treat atypical intracerebral haemorrhage when resources are limited. The presented cases highlight the importance of decisionmaking in resource-constrained situations when patient outcomes can be improved.

Epilepsy surgery program in a resource-limited setting in Vietnam: A multicentered collaborative model

OBJECTIVE

Although epilepsy surgery is more effective than medical therapy for drug-resistant patients, it is underutilized in both high-income and low- and middle-income countries. In light of our efforts to establish an epilepsy surgery program in a resource-limited setting, this study aimed to determine the outcome of the epilepsy surgery program in Ho Chi Minh City (HCMC), Vietnam.

METHODS

In 2018, we developed the HCMC epilepsy core multidisciplinary team with members from various hospitals and centers. The team typically included neurologists, neurosurgeons, neuropsychologists, psychiatrists, and nursing specialists. Presurgical evaluations were performed for patients with drug-resistant epilepsy, fulfilling the ILAE criteria, with an epileptogenic lesion (mesial temporal sclerosis, low-grade gliomas, or focal cortical dysplasia). All epilepsy surgeries were performed in two epilepsy surgery centers in HCMC between 2018 and 2021. The patients were followed up for at least 12 months.

RESULTS

Fifty-two patients with drug-resistant epilepsy underwent presurgical evaluation, of which 35 underwent surgery. Among the 52 patients, 20 (38.5%) underwent surgery after showing concordance among the results of standard presurgical assessments such as semiology, scalp interictal or ictal electroencephalography, and brain imaging. Among the 26 people with epilepsy who required more advanced evaluations, 15 underwent surgery with intraoperative electrocorticography to delineate the optimal resection borders. The outcomes of Engel Class I and Class II were achieved in 29/35 (82.8%) and 6/35 (17.2%) patients, respectively.

SIGNIFICANCE

The epilepsy surgery program with a multicentered collaborative model in a resource-limited setting showed favorable outcomes in HCMC, Vietnam.

Seizure remission rates remain low in a resource-limited country, a multicentre comparison study in Malaysia

Seizure remission rates of 60% with antiseizure medications were reported in developed countries, but might be lower in resource-limited countries. The challenges in epilepsy care in resource-limited regions were highlighted 10 years ago, and still remain an ongoing issue. This study aimed to determine the seizure freedom rates in level-2 epilepsy care centres (centres with general neurologists) compared to level-3/4 centres (centres with epileptologists providing epilepsy surgery evaluation) in Malaysia. This is a retrospective study of 1,347 adult epilepsy patients from two level-2 (n = 290) and two level-3/4 epilepsy care centres (n = 1,057). The seizure remission rates were significantly lower in level-2 centres (42.5%) compared to the level 3/4 centres (61.9%, p < 0.05). Level-2 centres had significantly more patients with undetermined seizure types compared to level-3/4 centres (6.6% vs 3.1%, p < 0.05). Level-3/4 centres had significantly more patients with epilepsy of structural and genetic origins, whereas more patients in level-2 centres had unknown aetiology (46.2% vs. 34.0% in level-3/4, p < 0.05). Level-2 centres had a lower neurologist-to-patient ratio (1:97 vs. 1:50 in level-3/4 centres, p < 0.05). Level-2 centres also had fewer patients, who underwent investigations such as EEG (74.1% vs. 89.6%) and brain MRI (54.1% vs. 72.4%, p < 0.05) in comparison with level-3/4 centres. Our study emphasized the existing challenges in epilepsy care in a resource-limited country to achieve the ideal 60% seizure remission rate.

Epilepsy surgery in Africa: state of the art and challenges

OBJECTIVE

Epilepsy is an important public health problem representing 0.6% of the global burden of disease that particularly impacts people living in the lowest income countries where epilepsy incidence may be 10 fold more than in the developed world. The battery of treatments designed to counteract the clinical manifestations of this disease are various and range from a wide spectrum of antiseizure medicationand specific diets, to surgical techniques for resection of the epileptogenic focus. The aim of our study was to describe the State of the art of Epilepsy Surgery (ES) in Africa and examine ways to deal with the high surgical treatment gap.

METHODOLOGY

In an observational study, we prospectively disseminated questionnaires via email or directly administered to main epileptologists and neurologists involved in epilepsy care, in key African countries. We also conducted a literature search using PubMed, Google scholar on ES in all the African countries.

RESULTS

We received responses from the majority of African countries, which allowed us to identify 3 levels of care for ES in African countries, a first level that uses ES with invasive presurgical evaluation, a second level that uses ES but without invasive presurgical evaluation, and a third level that does not use ES, and we summarized these results on a map.

DISCUSSION

This paper studied the availability of ES as a treatment modality in several African countries. We aimed to establish optimal pathways for initiating ES with noninvasive Electroencephalography and readily available investigations. This could be achieved through collaboration with epilepsy programs in developed countries directly or by using telemedicine.

Initiating an epilepsy surgery program with limited resources in Indonesia

To share the experiences of organizing the epilepsy surgery program in Indonesia. This study was divided into two periods based on the presurgical evaluation method: the first period (1999–2004), when interictal electroencephalogram (EEG) and magnetic resonance imaging (MRI) were used mainly for confirmation, and the second period (2005–2017), when long-term non-invasive and invasive video-EEG was involved in the evaluation. Long-term outcomes were recorded up to December 2019 based on the Engel scale. All 65 surgical recruits in the first period possessed temporal lobe epilepsy (TLE), while 524 patients were treated in the second period. In the first period, 76.8%, 16.1%, and 7.1% of patients with TLE achieved Classes I, II, and III, respectively, and in the second period, 89.4%, 5.5%, and 4.9% achieved Classes I, II, and III, respectively, alongside Class IV, at 0.3%. The overall median survival times for patients with focal impaired awareness seizures (FIAS), focal to bilateral tonic–clonic seizures and generalized tonic–clonic seizures were 9, 11 and 11 years (95% CI: 8.170–9.830, 10.170–11.830, and 7.265–14.735), respectively, with p = 0.04. The utilization of stringent and selective criteria to reserve surgeries is important for a successful epilepsy program with limited resources.

Initiating a new national epilepsy surgery program: Experiences gathered in Georgia

Surgery is the most effective therapeutic approach for medically refractory epilepsies and a safe and cost-efficient treatment in terms of long-term expenses of direct, indirect, and intangible costs. Georgia is a Caucasian low- to middle-income country with a remarkable effort to deal with epileptic diseases, but without an appropriate epilepsy surgery program. To address the needs for such a service in this country, two joint German-Georgian projects were initiated in 2017 and 2019. In the framework of these projects, a productive exchange program involving German and Georgian experts was undertaken in the past two years. This program included training and mentoring for Georgian clinical colleagues, as well as joint case conferences and workshops with the aim of optimizing presurgical diagnostics and preparing for an epilepsy surgery program in Georgia. Finally, a postsurgical medium- and long-term follow-up scheme was organized as the third component of this comprehensive approach. As a result of our efforts, the first patients underwent anterior temporal lobectomy and all of them remain seizure-free up to the present day. Hence, epilepsy surgery is not only feasible, but also already available in Georgia. In this report, we aim to share our experiences in the initiation and implementation of surgical epilepsy intervention in Georgia and illustrate our recent endeavor and achievements.

Corpus callosotomy for treatment of drug-resistant epilepsy: a review of 16 pediatric cases in northern Vietnam

OBJECTIVE

The aim of this study was to evaluate postoperative seizure outcome in children with drug-resistant epilepsy not eligible for focal resection who underwent corpus callosotomy.

METHODS

The study included 16 patients undergoing corpus callosotomy between September 2015 and May 2018. Seizure semiology and frequency, psychomotor status, and video electroencephalography and imaging findings were evaluated for all patients.

RESULTS

Of the 16 patients who underwent callosotomy during the study period, 11 underwent complete callosotomy and 5 underwent anterior only. Seizure improvement greater than 75% was achieved in 37.5% of patients, and another 50% of patients had seizure improvement of 50%-75%. No sustained neurological deficits were observed in these patients. There were no significant complications. Duration of postoperative follow-up ranged from 12 to 44 months.

CONCLUSIONS

Corpus callosotomy is an effective treatment for selected patients with drug-resistant epilepsy not eligible for focal resection in resource-limited settings. Fostering and developing international epilepsy surgery centers should remain a high priority for the neurosurgical community at large.

Health-related quality of life after epilepsy surgery: A prospective, controlled follow-up on the Iranian population

Quality of life is affected by factors such as regional differences in access to treatment choices, and rehabilitation. This study aims to assess the result of epilepsy surgery and its impact on QoL in Iran. The data for 60 patients who underwent epilepsy surgery in Loghman-Hakim hospital between 2003 to 2017 were analyzed prospectively through clinical observation. Clinical variables of interest and the WHOQOL-BREF scale to assess QoL were applied. Scores of operated patients were compared to their preoperative scores as well as epileptic patients controlled with antiepileptic drugs (AEDs) and healthy individuals. The mean age of surgery group patients was 33.78 (34 male; 26 female). Twenty seven patients underwent temporal mesial lobectomy, 20 anterior callosotomy, and 13 neocortical resections. The average QoL score in healthy group was 72.48, in AEDs controls was 56.16, and in operated patients was 65.61. In addition, analysis showed a significant increase in postoperative QoL of the surgical group compared to the AEDs controls. Epilepsy surgery could be the best approach in patients suffering from drug-resistant epilepsy even in developing countries, which can result in seizure relief and a reduction in the frequency of disabling seizures.

Underutilization of epilepsy surgery in ASEAN countries

PURPOSE

This survey was performed to determine the availability of epilepsy surgery, and understand the limiting factors to epilepsy surgery in ASEAN countries with total of 640 million population.

METHOD

A cross-sectional survey was completed by national representatives in all ASEAN countries (Brunei, Cambodia, East Timor, Indonesia, Laos, Malaysia, Myanmar, Philippines, Singapore, Thailand, and Vietnam).

RESULTS

Overall facilities for initial epilepsy pre-surgical evaluation are available in most countries, but further non-invasive and invasive investigations are limited. Three countries (Brunei, Cambodia, and East Timor) have no epilepsy center, and 2 countries (Laos, Myanmar) have level 2 centers doing tumor surgery only. Level-3 epilepsy centers are available in 6 countries (Indonesia, Malaysia, Philippine, Singapore, Thailand, Vietnam); only 5 countries (Indonesia, Malaysia, Philippine, Singapore, Thailand) has at least one level-4 epilepsy care facility. Indonesia with 261 million population only has one level 3 and another level 4 center. The costs of presurgical evaluation and brain surgery vary within and among the countries. The main barriers towards epilepsy surgery in ASEAN include lack of expertise, funding and facilities.

CONCLUSIONS

Epilepsy surgery is underutilized in ASEAN with low number of level 3 centers, and limited availability of advanced presurgical evaluation. Lack of expertise, facilities and funding may be the key factors contributing to the underutilization.

The experience of the multidisciplinary team in epilepsy management from a resource-limited country

OBJECTIVE

The use of multidisciplinary teams (MDTs) is a global trend in disease management, while China is still at the exploratory stage MDTs. We aimed to summarize our experience and assess the impact of MDT use in managing patients with epilepsy and optimizing their seizure outcomes.

METHODS

Our MDT is staffed with skilled epileptologists, electroencephalography experts, neurosurgeons, child neurologists, radiologists, and psychiatrists. The MDT discussion has been carried out once or twice a week since 2013. We reviewed our consecutive patients discussed at our MDT from March 2013 to December 2017. The detailed clinical characteristics, suggestions, and follow-up data were collected and analyzed.

RESULTS

A total of 1088 patients (604 male, 484 female) were included in this study. The median age at MDT discussion was 21 years (range 10 months to 79 years). Three hundred eighty-seven patients (35.6%) were younger than18 years of age. The median age at seizure onset was 12 years (range 2 days to 77 years). Most patients (80.4%) had at least one seizure per month and most (77%) took 2 or more antiepileptic drugs. A total of 70.6% of patients reached the standard of drug-resistant epilepsy and 74.2% of brain magnetic resonance imaging (MRI) studies detected positive findings. After detailed MDT discussion, 18 patients were diagnosed as having nonepileptic diseases, including psychogenic nonepileptic seizure, syncope, sleep disorder, paroxysmal kinesigenic dyskinesia, withdrawal symptom, and cerebral palsy. Three hundred eighty-two patients (35.1%) were suitable for resective surgery. Among the postoperative patients successfully followed up for more than 1 year, 72.7% (136/187) received favorable outcomes (Engel class I). The seizure-free rate was 78.6% after temporal lobe surgery and 58.9% after extratemporal surgery.

SIGNIFICANCE

Epilepsy management can be optimized through MDT discussion to attain accurate diagnosis and favorable seizure outcomes. There is still room for MDT improvement in resource-limited countries.

Epidemiological profile of epilepsy in low income populations

Epilepsy is a global disease with an unequal distribution. About 80% of the affected individuals reside in low and middle income countries. The incidence and prevalence of epilepsy in low income populations is higher than in the rest of the world, this is partly explained by some risk factors such as head trauma, perinatal injury and CNS infections, which are more common in poor regions, especially in rural areas. Epilepsy is considered a treatable condition with high rates of therapeutic response. About three fourths of patients achieve control of the disease with the use of antiepileptic drugs, however, despite this benign prognosis, over 75% of patients from low income populations do not receive treatment at all. The cultural beliefs, the inequity in the distribution of public health services, the inadequate supply of antiepileptic drugs, the low number of neurologists involved in the attention of epilepsy, and the social stigma, are the main reasons that increase the treatment gap and the burden of disease in low income populations with epilepsy. We conducted a narrative review regarding the epidemiology of epilepsy in low income populations by searching PubMed, EMBASE, Google Scholar and thoroughly examining relevant bibliographies. This review aims to summarize the main epidemiological aspects of epilepsy in LMIC, emphasizing on incidence, prevalence, socio-demographic profile, TG, social stigma and QoL.

Long-Term Electroclinical and Employment Follow up in Temporal Lobe Epilepsy Surgery. A Cuban Comprehensive Epilepsy Surgery Program

The purpose of this paper is to present a long- term electroclinical and employment follow up in temporal lobe epilepsy (TLE) patients in a comprehensive epilepsy surgery program. Forty adult patients with pharmacoresistant TLE underwent detailed presurgical evaluation. Electroencephalogram (EEG) and clinical follow up assessment for each patient were carried out. The occurrence of interictal epileptiform activity (IEA) and absolute spike frequency (ASF) were tabulated before and after 1, 6, 12, 24 and 72 months surgical treatment. Employment status pre- to post-surgery at the last evaluated period was also examined. Engel scores follow-up was described as follows: at 12 months 70% (28) class I, 10% (4) class II and 19% (8) class III-IV; at 24 months after surgery 55.2% (21) of the patients were class I, 28.9% (11) class II and 15.1% (6) class III-IV. After one- year follow up 23 (57.7%) patients were seizure and aura-free (Engel class IA). These figures changed to 47.3%, and 48.6% respectively two and five years following surgery whereas 50% maintained this condition in the last follow up period. A decline in the ASF was observed from the first year until the sixth year after surgery in relation to the preoperative EEG. The ASF one year after surgery allowed to distinguish “satisfactory” from “unsatisfactory” seizure relief outcome at the last follow up. An adequate social functioning in terms of education and employment in more than 50% of the patients was also found. Results revealed the feasibility of conducting a successful epilepsy surgery program with favorable long term electroclinical and psychosocial functioning outcomes in a developing country as well.

Corpus Callosotomy for Patients With Intractable Seizures: An Insight Into the Rapid Relapse

It is well known that corpus callosotomy (CC) can bring a favorable seizure control outcome for disabling generalized seizures, but the complete remission rate achieved by CC is rarely reported, and the postoperative relapse pattern is still not clear. In this study, the authors reviewed patients with medically refractory epilepsy who were suffering disabling seizures, including drop attacks, generalized tonic-clonic seizures (GTCS), tonic seizures, atonic seizures, atypical absences, and complex partial seizures. The patients underwent anterior two third or complete CC in our hospital. Seizure control outcome was evaluated postoperatively at 2 weeks, 1 month, 3 months, 6 months, thereafter, at yearly intervals. Seizure-free or >90% reduction was considered to be satisfactory. There were 14 patients with mean age 11.00 ± 6.34 at surgery. Of all the patients, 6 patients underwent anterior two third CC, and the other 8 patients underwent complete CC. All the patients were postoperatively followed up for at least 1 year. Four patients (28.57%) were free of all seizure types in the first year after surgery. Among the 9 patients with follow-up longer than 3 years, 2 patients (22.22%) were free of all seizure types. In the first 3 months after surgery, more than half of the seizure free patients (55.56%) relapsed with the same seizure types as preoperatively. Although after that, there was only 1 patient relapsed. Of all the seizure types, CC achieved the most favorable seizure outcome in drop attacks. In conclusion, CC could achieve complete seizure remission in a small portion of selected candidates. Exploration of the relapse mechanism will contribute to improve the seizure outcome following CC.

Neuroimaging for patient selection for medial temporal lobe epilepsy surgery: Part 1 Structural neuroimaging

The objective of part one of this review is to present the structural neuroimaging techniques that are currently used to evaluate patients with temporal lobe epilepsy (TLE), and to discuss their potential to define patient eligibility for medial temporal lobe surgery. A PubMed query, using Medline and Embase, and subsequent review, was performed for all English language studies published after 1990, reporting neuroimaging methods for the evaluation of patients with TLE. The extracted data included demographic variables, population and study design, imaging methods, gold standard methods, imaging findings, surgical outcomes and conclusions. Overall, 56 papers were reviewed, including a total of 1517 patients. This review highlights the following structural neuroimaging techniques: MRI, diffusion-weighted imaging, tractography, electroencephalography and magnetoencephalography. The developments in neuroimaging during the last decades have led to remarkable improvements in surgical precision, postsurgical outcome, prognosis, and the rate of seizure control in patients with TLE. The use of multiple imaging methods provides improved outcomes, and further improvements will be possible with future studies of larger patient cohorts.

Impact of sleep on the localizing value of video EEG in patients with refractory focal seizures - a prospective video-EEG with EOG and submental EMG study

OBJECTIVES

To examine the role of sleep and its stages on the localizing value of video EEG in the evaluation of refractory focal seizures.

METHODS

Video-electroencephalographic (VEEG) evaluation with additional polygraphic recording was carried out for 70 consecutive patients with refractory focal epilepsy, undergoing pre-surgical evaluation, over a two-year period. Localization of video EEG for each seizure was made based on clinical, ictal and interictal data. Seizure localization in each patient was assessed for concordance with MRI and other imaging data (SPECT, PET) for both wake and sleep seizures. Interictal discharges in sleep and wake were similarly compared for concordance with imaging data.

RESULTS

A total of 608 seizures were recorded in 70 patients, 289 in sleep. Overall, concordance with imaging data was found in 218 out of 322 wake seizures (67.8%) and in 157 out of 286 sleep seizures (54.8%) (p=0.0314). On analyzing the subset of patients with seizures recorded in both wake and sleep states (total 279 seizures recorded, 113 out of sleep), concordance was observed in 93 out of 166 (56%) wake seizures and in 80 out of 113 (70.7%) sleep seizures (OR 2.03, 95% CI 1.17 to 3.56; p 0.007). Interictal discharges were more common and more precisely localizing in sleep, mostly in stage N2.

CONCLUSIONS

This prospective VEEG-PSG study demonstrates the role of sleep versus wake state in the localizing value of different components of long-term VEEG recording for patients with medically refractory epilepsy. Our findings show that while wake state ictal EEG has more localizing value in a mixed group of patients, sleep ictal and interictal EEG is significantly more useful in patients who have seizures recorded both during wake and sleep states. In addition, interictal discharges recorded during NREM sleep have high localizing value.

SIGNIFICANCE

This is only the second study elucidating the effect of sleep on the localizing value of video-electroencephalographic evaluation of patients with medically refractory focal epilepsy; mainly revealing high value of sleep interictal discharges and that sleep ictal recording has two times higher localizing value than wake ictal recording, among patients in whom seizures are recorded in both states.

Corpus callosotomy is a valuable therapeutic option for patients with Lennox-Gastaut syndrome and medically refractory seizures

PURPOSE

We present our experience with corpus callosotomy (CC) in a developing country with limited resources in patients with Lennox-Gastaut syndrome (LGS) and medically refractory seizures.

METHODS

All patients with LGS who underwent CC for medically refractory epilepsy at Namazee Hospital, Shiraz University of Medical Sciences, Shiraz, Iran from May 2009 through March 2012 were reviewed in a retrospective study. Presurgical evaluation included clinical history, neurological examination, a 2-hour video-EEG recording, and 1.5-T MRI. Outcome was evaluated at 6, 12, and 24 months postoperatively. We considered the outcome as a success if the patients were either seizure-free or had more than 85% reduction in seizure frequency compared to their preoperative status.

RESULTS

Eighteen patients (14 males and 4 females) had surgery. Overall, seizures in 11 patients (61.1%) responded favorably one year after surgery; this figure was 6 out of 9 patients (66.6%) two years after surgery. Seven patients (38.8%) were free of disabling seizures one year after CC; this figure was three out of nine patients (33.3%) two years after CC. Three patients (16.6%) were free of all seizure types one year after surgery. Ten patients (55.5%) had no postoperative complications of any kind.

CONCLUSION

Corpus callosotomy is an effective palliative surgical procedure for patients with LGS with intractable seizures whose seizures are not amenable to focal resection. This is a feasible treatment option for patients, even for those in developing countries with limited resources.

Epilepsy in poor regions of the world

Epilepsy is a common disorder, particularly in poor areas of the world, and can have a devastating effect on people with the disorder and their families. The burden of epilepsy in low-income countries is more than twice that found in high-income countries, probably because the incidence of risk factors is higher. Many of these risk factors can be prevented with inexpensive interventions, but there are only a few studies that have assessed the effect of reducing risk factors on the burden of epilepsy. The mortality associated with epilepsy in low-income countries is substantially higher than in less impoverished countries and most deaths seem to be related to untreated epilepsy (eg, as a result of falls or status epilepticus), but the risk factors for death have not been adequately examined. Epilepsy is associated with substantial stigma in low-income countries, which acts as a barrier to patients accessing biomedical treatment and becoming integrated within society. Seizures can be controlled by inexpensive antiepileptic drugs, but the supply and quality of these drugs can be erratic in poor areas. The treatment gap for epilepsy is high (>60%) in deprived areas, but this could be reduced with low-cost interventions. The substantial burden of epilepsy in poor regions of the world can be reduced by preventing the risk factors, reducing stigma, improving access to biomedical diagnosis and treatment, and ensuring that there is a continuous supply of good quality antiepileptic drugs.

Establishment of a comprehensive epilepsy center in pakistan: initial experiences, results, and reflections

Background. Developing countries, home to 80% of epilepsy patients, do not have comprehensive epilepsy surgery programs. Considering these needs we set up first epilepsy surgery center in Pakistan. Methods. Seventeen teleconferences focused on setting up an epilepsy center at the Aga Khan University (AKU), Karachi, Pakistan were arranged with experts from the University of Alberta Hospital, Alberta, Canada and the University of West Virginia, USA over a two-year period. Subsequently, the experts visited the proposed center to provide hands on training. During this period several interactive teaching sessions, a nationwide workshop, and various public awareness events were organized. Results. Sixteen patients underwent surgery, functional hemispherectomy (HS) was done in six, anterior temporal lobectomy (ATL) in six, and neuronavigation-guided selective amygdalohippocampectomy (SAH) using keyhole technique in four patients. Minimal morbidity was observed in ATL and, SAH groups. All patients in SAH group (100%) had Grade 1 control, while only 5 patients (83%) in ATL group, and 4 patients (66%) in HS group had Grade 1 control according to Engel's classification, in average followups of 12 months, 24 months and 48 months for SAH, ATL, and HS, respectively. Conclusion. As we share our experience we hope to set a practical example for economically constrained countries that successful epilepsy surgery centers can be managed with limited resources.

Skull base surgery in a large, resource-poor, developing country with few neurosurgeons: prospects, challenges, and needs

BACKGROUND

Upon returning home to Nigeria from postresidency fellowship training in skull base surgery, using expertise gained overseas, we applied appropriate treatment to various skull base pathologies. This is an audit of our initial experience.

METHODS

This is a prospective, descriptive survey of all the skull base pathologies operated on during 30 months. Clinical-demographic data, surgical procedures, and the postoperative outcome are presented statistically. Simple inferential statistics was performed for associations deemed significant at P≤0.05.

RESULTS

Fifty-one individuals (27 men and 24 women, mean age 32 years) were operated on for skull base pathologies. Clinical presentation had a mean symptom duration of 22 months and a poor clinical status in more than 60% of the patients. Congenital, infective, traumatic, and neoplastic lesions were encountered, including craniofacial malignancies operated on jointly with other craniofacial surgeons. Other intracranial neurosurgical pathologies like jugular foramen and brain stem tumors, and meningiomas of various skull base corridors, including the cavernous sinus and the foramen magnum, were encountered. Our skull base dissections were craniofacial in 23.5% of cases, anterolateral in 33.3%, midbasal in 15.7%, and posterior fossa in 27.5% of patients. Surgery was successful in 86.3%. The patients' status improved on hospital discharge in 70.6% of cases. The postoperative outcome was significantly worse (P=0.03) in those patients with postbasal lesions with poor clinical performance index preoperatively.

CONCLUSIONS

In spite of the many inherent challenges of a typical developing country health system, there are great prospects for skull base surgical practice in Nigerian neurological surgery.

Epilepsy surgery in Argentina: long-term results in a comprehensive epilepsy centre

RATIONALE

Epilepsy surgery procedures started in Argentina more than 50 years ago. This is the first comprehensive and systematic survey of epilepsy surgery long-term outcome from our country.

METHODS

A descriptive cohort study was conducted between 1998 and 2008 for drug-resistant epilepsy surgery with a minimum of 12 months follow-up (n=110). In 84 cases (76.36%) resective surgery was performed, and outcome periodically assessed using the Engel score. Patients were stratified into groups: 12, 13-36, 37-60 and over than 60 months of follow-up. Video-EEG with and without intracranial electrode implants, intraoperative electrocorticograms, Wada tests, pathology reports, use of antiepileptic drugs (AEDs), and surgical complication rates were evaluated.

RESULTS

Surgical techniques included: 69 lobectomies (62.7%), 15 lesionectomies (13.6%), 6 callosotomies (5.4%), 6 multiple subpial transection (5.4%), 11 vagus nerve stimulations (10%), 3 hemispherectomies (2.7%). Male: female ratio: 1/1.44. Mean age at time of surgery: 26.2 years. Mean duration of epilepsy: 14 years. Age at seizure onset: 11.5 years. Mean follow-up: 46 months. Pathology findings: mesial temporal sclerosis 32 (35.1%); dual pathology 17 (18.7%); cortical dysplasia 15 (16.4%); non-specific inflammatory changes 11 (12.1%); tumors 7 (7.7%); other 6 (6.8%). Engel scores at 12 months follow-up: 72.6% (61) class I, 16.6% (14) class II and 15.5% (13) class III-IV; 13-36 months after surgery: 68.1% of cases were class I, 15.9% class II and 15.5% class III-IV. After 37-60 months, 74% class I, 14% class II, 14% class III-IV. Over 60 months (n=45) 78% class I, 13.5% class II and 8.1% class III-IV.

CONCLUSION

Conducting a successful epilepsy surgery program in a developing country is challenging. These results should encourage specialists in these countries. Long-term outcome results comparable to centres in developed countries can be achieved.

Presidential oration: the 18 annual conference of the Indian academy of neurology, trichi, Tamil Nadu, september 24-26, 2010, epilepsy care in developing countries

Nearly 80% of the 50 million people with epilepsy worldwide reside in developing countries that are least equipped to tackle the enormous medical, social and economic challenges posed by epilepsy. These include widespread poverty, illiteracy, inefficient and unevenly distributed health care systems, and social stigma and misconceptions associated with epilepsy. Several studies have reported that a large proportion of patients with epilepsy in developing countries never receive appropriate treatment for their condition, and many, though diagnosed and initiated on treatment, soon discontinue treatment. Unaffordable cost of treatment, unavailability of antiepileptic drugs, and superstitious and cultural beliefs contribute to high epilepsy treatment gap in resource-poor countries. A significant proportion of the current burden of epilepsy in developing countries can be minimized by educating the public about the positive aspects of life with epilepsy and the primary and secondary physicians about current trends in the management of epilepsies, scaling up routine availability of low-cost antiepileptic drugs, and developing cost-effective epilepsy surgery programs.

Packages of care for epilepsy in low- and middle-income countries

In the second in a series of six articles on packages of care for mental health disorders in low- and middle-income countries, Caroline Mbuba and Charles Newton discuss treatment for epilepsy.

Corpus callosotomy

Corpus callosotomy is a palliative surgical procedure that is suitable for some patients with intractable seizures who are not candidates for focal resective surgery. The rationale for this procedure is based on the hypothesis that the corpus callosum is a critical pathway for interhemispheric spread of epileptic activity. Efficacy and relatively low permanent morbidity in corpus callosotomy for medically intractable epilepsy have been demonstrated by more than six decades of experience. Callosotomy best ameliorates drop attacks (tonic and atonic seizures), though tonic-clonic, absence, and frontal lobe complex partial seizures often respond as well. In addition to seizure reduction, behavior and quality of life may improve. Hence, callosotomy is justified as a therapy for appropriate patients with intractable epilepsy.