High prevalence of epilepsy in a village in the Littoral Province of Cameroon

Ethanolic and aqueous extracts of Lantana camara show antiepileptic and anxiolytic effects by inhibiting the ferroptosis pathway in kainate-treated mice

In Cameroon, epilepsy is one of the most common neurological diseases. Available anti-epileptic medication, on the other hand, have been associated with pharmacological toxicity and emotional impairment. The identification of a more efficient replacement is critical. Recent research reveals that ferroptosis contributes to the pathophysiology of epilepsy and related anxiety disorders. Lantana camara is a plant with a high neuropharmacological potential, but its mechanisms of action have yet to be understood. The purpose of this study was to determine the effect of ethanolic and aqueous extracts of Lantana camara on the kainate model of epilepsy in mice. The focus was on these extracts' capacity to suppress ferroptosis. Mice were injected with kainate (12 mg/kg, i.p.) to induce epilepsy. After status epilepticus, animals were left for 19 days, which correspond to an epileptogenic period. After the appearance of spontaneous recurrent seizures, mice were treated with distilled water (10 ml/kg, p.o.), levetiracetam (80 mg/kg, p.o.), sodium valproate (300 mg/kg, p.o.), ethanolic extract of L. camara (230, 460, 920 mg/kg, p.o.), or an aqueous extract of L. camara (460 mg/kg p.o.). These treatments lasted for 14 days. During this period, the number and duration of seizures were recorded. The mice were then subjected to elevated zero-maze and open field tests to assess anxiety-like behavior. At the end, mice were sacrificed and hippocampus, amygdala, and striatum were dissected out for biochemical and histological analyses. The extracts alleviated seizure- and anxiety-like behavior in KA-treated mice. Decreased iron levels, reflected by a decrease in ferritin levels and a increase in transferrin levels, were observed in the hippocampus, striatum and amygdala of the extract-treated group compared to the KA-treated group. In addition, increase in GABA and GSH levels, and a decrease in MDA levels were observed in these groups. Hematoxylin-eosin staining revealed less pronounced neuronal degeneration and a more sustained architecture in the brain region of extract-treated mice. These findings indicated that ethanolic and aqueous extracts of L. camara effectively attenuate seizures and anxiety disorders. Probable mechanisms of action include GABAergic, iron, GSH, and MDA modulations.

Prevalence, incidence, and trends of epilepsy among children and adolescents in Africa: a systematic review and meta-analysis

BACKGROUND

Epilepsy contributes to a significant disease burden in children and adolescents worldwide. The incidence of childhood epilepsy is threefold higher in low and middle income countries compared in high-income countries. Epilepsy is a serious neurological condition associated with stigma and discrimination, an impaired quality of life, and other mental health related problems.

OBJECTIVE

This study is aimed to synthesize existing evidence and estimate the pooled prevalence and incidence of epilepsy in children and adolescents in Africa.

METHODS

A comprehensive and systematic search of relevant databases was conducted. The quality of each study was assessed using the Newcastle-Ottawa Quality Assessment Scale adapted for meta-analysis. Two reviewers screened retrieved articles, conducted critical appraisals, and extracted the data. Heterogeneity between studies was assessed by visual inspection of forest plots and statistically using Cochran's Q statistics and the I2 test. Publication bias was checked by visual inspection of funnel plots as well as statistically using Egger's correlation and Begg's regression tests. Finally, the pooled prevalence and incidence of childhood epilepsy were computed with 95% confidence intervals.

RESULT

In this review and meta-analysis 42 studies with 56 findings were included to compute the pooled prevalence of childhood epilepsy. On the other hand, 6 studies were included to estimate the combined incidence. The pooled prevalence of cumulative epilepsy was 17.3 per 1000 children. Whereas the pooled prevalence of active and lifetime epilepsy was 6.8 and 18.6 per 1000 children respectively. The pooled incidence of childhood epilepsy was 2.5 per 1000 children.

CONCLUSION

Nearly 1 in 50 children are suffering from epilepsy in Africa. However, little attention has been paid to the prevention and treatment of childhood epilepsy. Mass epilepsy screening, scaling up treatment coverage, and designing strict treatment follow up and monitoring mechanisms are recommended.

Very high epilepsy prevalence in rural Southern Rwanda: The underestimated burden of epilepsy in sub-Saharan Africa

OBJECTIVES

Up to 85% of people living with epilepsy (PwE) reside in low-and middle-income countries. In sub-Saharan Africa, the lifetime prevalence of epilepsy is 16 per 1000 persons. In Northern rural Rwanda, a 47.7 per 1000 prevalence has been reported. As variations in prevalence across geographical areas have been observed, we studied the prevalence in Southern rural Rwanda using the same robust methodology as applied in the North.

METHODS

We conducted a three-stage, cross-sectional, door-to-door survey in two rural villages in Southern Rwanda from June 2022 to April 2023. First, trained enumerators administered the validated Limoges questionnaire for epilepsy screening. Second, neurologists examined the persons who had screened positively to confirm the epilepsy diagnosis. Third, cases with an inconclusive assessment were separately reexamined by two neurologists to reevaluate the diagnosis.

RESULTS

Enumerators screened 1745 persons (54.4% female, mean age: 24 ± 19.3 years), of whom 304 (17.4%) screened positive. Epilepsy diagnosis was confirmed in 133 (52.6% female, mean age: 30 ± 18.2 years) and active epilepsy in 130 persons. Lifetime epilepsy prevalence was 76.2 per 1000 (95% CI: 64.2-89.7‰). The highest age-specific rate occurred in the 29-49 age group. No gender-specific differences were noted. In 22.6% of the PwE, only non-convulsive seizures occurred. The treatment gap was 92.2%, including a diagnosis gap of 79.4%.

CONCLUSION

We demonstrated a very high epilepsy prevalence in Southern rural Rwanda, with over 20% of cases having only non-convulsive seizures, which are often underdiagnosed in rural Africa. In line with previous Rwandan reports, we reiterate the high burden of the disease in the country. Geographic variation in prevalence throughout Africa may result from differences in risk and aetiological factors. Case-control studies are underway to understand such differences and propose adapted health policies for epilepsy prevention.

Mapping, Associated Factors, and Pathophysiology of Nodding Syndrome in Africa: A Systematic Review

INTRODUCTION

Nodding syndrome (NS) remains a poorly understood disorder. For a long time, it has been thought to be restricted to East Africa; however, cases in Central Africa have been increasing over time. The objective of this systematic review (SR) was to provide a summary of the state of knowledge on NS to date.

METHODS

All original articles published on NS up to November 2021 were searched in four major databases and in the gray literature. Commentaries, editorials, book chapters, books, conference paper, qualitative studies that mentioned NS cases were also included. Data retrieved included study location (with GPS coordinates searched), year of study and publication, population characteristics, definition and diagnosis of NS, associated factors, and treatment if applicable. A meta-analysis of associated factors was performed where possible, and results were presented as odds ratios (ORs) and visualized as forest plots. Geographic information systems were used for cartographic representations. The quality of the articles included was assessed.

RESULTS

Of the 876 articles initially identified, 67 (corresponding to 59 studies) were included in the SR. NS is only present in Central and East Africa. Interestingly, there were reports of NS in Central Africa prior to 2010, earlier than previously thought. The way NS diagnosis was established varies according to studies, and the 2012 WHO classification was used in only 60% of the studies. Approximately 11% of the articles did not meet the quality requirements set for this review. In our meta-analysis, the main factor associated with NS was onchocerciasis (OR = 8.8 [4.8, 15.9]). However, the pathophysiology of the disease remains poorly understood. The lack of common anti-epileptic drugs is a significant barrier to the management of head nodding and associated epileptic seizures.

DISCUSSION/CONCLUSION

The lack of an operational definition of NS is an obstacle to its diagnosis and, thus, to its appropriate treatment. Indeed, diagnostic difficulties might have led to false positives and false negatives which could have altered the picture of NS presented in this article. Treatment should take into account nutritional and psychological factors, as well as associated infections. Some risk factors deserve further investigation; therefore, we suggest a multicentric study with an etiological focus using a more operational definition of NS.

Prevalence of epilepsy in Morocco: A population-based study

OBJECTIVE

In Morocco, there was a lack of data related to the epidemiology of epilepsy. This data serves as a useful basis for the development of any national intervention or action program against epilepsy in Morocco. Through this study, we aimed to estimate the active and lifetime prevalence of epilepsy in Morocco.

METHODS

We collected data from eight out of 12 Moroccan regions in two steps: In the screening step, we first used a nationwide telephone diagnosis questionnaire and in the second stage, a team of physicians under the direction of an epileptologist conducted a confirmative survey for suspected cases. We fixed the confidence interval at α = 5% and the precision at 0.02.

RESULTS

Up to 3184 responded positively to our invitation to participate in this study and were able to answer the questions of the first diagnostic questionnaire. In the diagnostic phase, physicians in neurology reinterviewed all 86 suspected cases using a confirmative diagnosis questionnaire, and 63 persons were confirmed as having lifetime epilepsy and 56 with active epilepsy. The mean age (Mean ± SD) of persons with epilepsy was 35.53 years (±21.36). The prevalence of lifetime and active epilepsy were 19.8 (19.6-20.0) and 17.6 (17.5-17.8) per 1000 (95% confidence interval), respectively.

SIGNIFICANCE

This is the first study to estimate the active and lifetime prevalence of epilepsy in Morocco according to the international recommendations of the ILAE. The prevalence of lifetime and active epilepsy were 19.8 (15-24.6) and 17.6 (13.3-22.8) per 1000, respectively. We included both children and elderly subjects. The rates of active and lifetime population epilepsy prevalence in Morocco ranged between Asian and sub-Saharan Africa low- and middle-income countries.

Ameliorative effects of Albizia adianthifolia aqueous extract against pentylenetetrazole-induced epilepsy and associated memory loss in mice: Role of GABAergic, antioxidant defense and anti-inflammatory systems

Albizia adianthifolia (Schumach.) (Fabaceae) is a medicinal herb used for the treatment of epilepsy and memory impairment. This study aims to investigate the anticonvulsant effects of Albizia adianthifolia aqueous extract against pentylenetetrazole (PTZ)-induced spontaneous convulsions in mice; and determine whether the extract could mitigate memory impairment, oxidative/nitrergic stress, GABA depletion and neuroinflammation. Ultra-high performance liquid chromatography/mass spectrometry analysis was done to identify active compounds from the extract. Mice were injected with PTZ once every 48 h until kindling was developed. Animals received distilled water for the normal group and negative control groups, doses of extract (40, 80, or 160 mg/kg) for the test groups and sodium valproate (300 mg/kg) for the positive control group. Memory was measured using Y maze, novel object recognition (NOR) and open field paradigms, while the oxidative/nitrosative stresses (MDA, GSH, CAT, SOD and NO), GABAergic transmission (GABA, GABA-T and GAD) and neuro-inflammation (TNF-α, IFN-γ, IL- 1β, and IL-6) were determined. Brain photomicrograph was also studied. Apigenin, murrayanine and safranal were identified in the extract. The extract (80-160 mg/kg) significantly protected mice against seizures and mortality induced by PTZ. The extract significantly increased the spontaneous alternation and the discrimination index in the Y maze and NOR tests, respectively. PTZ kindling induced oxidative/nitrosative stress, GABA depletion, neuroinflammation and neuronal cells death was strongly reversed by the extract. The results suggest that the anticonvulsant activity of Albizia adianthifolia extract is accompanied by its anti-amnesic property, and may be supported by the amelioration of oxidative stress, GABAergic transmission and neuroinflammation.

Revealing the most effective anticonvulsant part of Malvaviscus arboreus Dill. Ex Cav. and its acute and sub-acute toxicity

ETHNOPHARMACOLOGY RELEVANCE

Different parts of Malvaviscus arboreus Dill. Ex Cav. (M. arboreus) are traditionally used in the West Region of Cameroon to treat many diseases, including epilepsy.

AIM OF THE STUDY

To determine which part of M. arboreus offers the best anticonvulsant effect, and to assess the acute and sub-acute toxicity of the part of interest.

MATERIALS AND METHODS

the anticonvulsant effect of the aqueous lyophilisate of the decoction of flowers, leaves, stems and roots of M. arboreus at various doses was evaluated and compared on the model of acute epileptic seizures induced by pentylenetetrazole (PTZ) (70 mg/kg), injected 1 h after oral administration of the various extracts. Out of these plant parts, the leaves were then selected to prepare the hydroethanolic extract and its anticonvulsant effect against PTZ at the doses of 122.5, 245 and 490 mg/kg, as well as its acute toxicity were compared with those of the aqueous lyophilisate of the leaves. The anticonvulsant effect of the aqueous lyophilisate of M. arboreus leaves was further evaluated on models of acute epileptic seizures induced by picrotoxin (PIC) (7.5 mg/kg), strychnine (STR) (2.5 mg/kg) and pilocarpine (350 mg/kg). The 28 days sub-acute toxicity, as well as the quantitative phytochemistry and the in vitro antioxidant potential (FRAP, DPPH, ABTS+) of the aqueous lyophilisate of the leaves of M. arboreus were also evaluated.

RESULTS

M. arboreus leaves showed the best anticonvulsant effect and the aqueous lyophilisate was the best extract. The latter significantly protected the animals against convulsions induced by PTZ (71.43%) (p < 0.01), PIC (57.14%) (p < 0.05) and STR (42%) and had no effect on pilocarpine-induced seizures. Furthermore, it showed no acute or sub-acute toxicity, and revealed a high content of flavonoids, saponins, tannins and alkaloids, and antioxidant activity in vitro.

CONCLUSION

The aqueous lyophilisate of the leaves of M. arboreus offers the best anticonvulsant effect on the extraction solvent used, and it would act mainly via a potentiation of the inhibitory systems of the brain (GABA, Glycine). In addition, its richness in bioactive compounds gives it an antioxidant potential, and it is not toxic in acute and sub-acute toxicity. All this justifies at least in part its empirical uses, and makes M. arboreus a candidate for the alternative treatment of epilepsy.

Prevalence of epilepsy in Ndom Health District (Littoral Region, Cameroon) after long-term ivermectin-based preventive chemotherapy for the control of onchocerciasis

Assuming the causality relationship between Onchocerca volvulus infection and epilepsy onset, preventive chemotherapy for the control onchocerciasis can result to a significant impact on epilepsy burden. This study aimed at assessing the prevalence of epilepsy in an onchocerciasis endemic area under annual CDTI for 16 years. A cross-sectional survey was conducted in two communities (Kelleng and Nkonkwalla) located in the Ndom Health District (Littoral Region, Cameroon) to assess the prevalence of epilepsy using a standardized questionnaire for non-specialists in tropical areas. Data on the nuisance of onchocerciasis vector and distance of surveyed households to the river were also collected. Epilepsy status was collected from 367 participants (sex ratio (M/F): 1.13). The crude prevalence of epilepsy was estimated at 8.4 % (95 % CI: 5.8-11.8); the highest prevalence was found in females (13.8 %; 95 % CI: 8.8-20.3) compared to males (5.0 %; 95 % CI: 2.4-9.04)) (p-value = 0.02) and in Nkonkwalla (9.0 %; 95 % CI: 5.5-13.6) (p-value = 0.82) compared to Kelleng (7.7 %; 95 % CI: 4.06-13.13). After 16 years of CDTI in Kelleng, crude prevalence of epilepsy decreased from 10.2 % to 7.2 % (p-value = 0.19), whereas the age sex-standardized prevalence dropped from 13.5 % to 7.7 % between 2004 and 2020 (p-value = 0.05). The median age of epilepsy cases shifted from 24 (IQR: 20-30) in 2004 to 28 years (IQR: 23-34) in 2020. The shift in age-specific prevalence over the years suggests a decreasing incidence of epilepsy in areas under long-term CDTI and a significant impact of onchocerciasis control on the prevalence of epilepsy.

An aqueous extract of Khaya senegalensis (Desv.) A. Juss. (Meliaceae) prevents seizures and reduces anxiety in kainate-treated rats: modulation of GABA neurotransmission, oxidative stress, and neuronal loss in the hippocampus

Ethnopharmacological relevance

Temporal lobe epilepsy is the most common form of drug-resistant epilepsy. Therefore, medicinal plants provide an alternative source for the discovery of new antiepileptic drugs.

Aim of the study

This study was aimed at investigating the antiepileptic- and anxiolytic-like effects of an aqueous extract of Khaya senegalensis (K. senegalensis) in kainate-treated rats.

Methods

Seventy-two rats received a single dose of kainate (12 mg/kg) intraperitoneally. Those that exhibited two hours of status epilepticus were selected and monitored for the first spontaneous seizure. Then, animals that developed seizures were divided into 6 groups of 8 rats each and treated twice daily for 14 days as follows: negative control group received per os (p.o.) distilled water (10 ml/kg); two positive control groups received either sodium valproate (300 mg/kg, p.o.) or phenobarbital (20 mg/kg, p.o.); and three test groups received different doses of the extract (50, 100, and 200 mg/kg, p.o.). In addition, a group of 8 normal rats (normal control group) received distilled water (10 ml/kg, p.o.). During the treatment period, the animals were video-monitored 12 h/day for behavioral seizures. At the end of the treatment period, animals were subjected to elevated plus-maze and open field tests. Thereafter, rats were euthanized for the analysis of γ-aminobutyric acid (GABA) concentration, oxidative stress status, and neuronal loss in the hippocampus.

Results

The aqueous extract of K. senegalensis significantly reduced spontaneous recurrent seizures (generalized tonic-clonic seizures) and anxiety-like behavior compared to the negative control group. These effects were more marked than those of sodium valproate or phenobarbital. Furthermore, the extract significantly increased GABA concentration, alleviated oxidative stress, and mitigated neuronal loss in the dentate gyrus of the hippocampus.

Conclusion

These findings suggest that the aqueous extract of K. senegalensis possesses antiepileptic- and anxiolytic-like effects. These effects were greater than those of sodium valproate or phenobarbital, standard antiepileptic drugs. Furthermore, these effects are accompanied by neuromodulatory and antioxidant activities that may be related to their behavioral effects. These data justify further studies to identify the bioactive molecules present in the extract for possible future therapeutic development and to unravel their mechanisms of action.

A Standardized Electrode Nomenclature for Stereoelectroencephalography Applications

PURPOSE

Stereoelectroencephalography (SEEG) is widely performed on individuals with medically refractory epilepsy for whom invasive seizure localization is desired. Despite increasing adoption in many centers across the world, no standardized electrode naming convention exists, generating confusion among both clinical and research teams.

METHODS

We have developed a novel nomenclature, named the Standardized Electrode Nomenclature for SEEG Applications system. Concise, unique, informative, and unambiguous labels provide information about entry point, deep targets, and relationships between electrodes. Inter-rater agreement was evaluated by comparing original electrode names from 10 randomly sampled cases (including 136 electrodes) with those prospectively assigned by four additional blinded raters.

RESULTS

The Standardized Electrode Nomenclature for SEEG Application system was prospectively implemented in 40 consecutive patients undergoing SEEG monitoring at our institution, creating unique electrode names in all cases, and facilitating implantation design, SEEG recording and mapping interpretation, and treatment planning among neurosurgeons, neurologists, and neurophysiologists. The inter-rater percent agreement for electrode names among two neurosurgeons, two epilepsy neurologists, and one neurosurgical fellow was 97.5%.

CONCLUSIONS

This standardized naming convention, Standardized Electrode Nomenclature for SEEG Application, provides a simple, concise, reproducible, and informative method for specifying the target(s) and relative position of each SEEG electrode in each patient, allowing for successful sharing of information in both the clinical and research settings. General adoption of this nomenclature could pave the way for improved communication and collaboration between institutions.

A peer support group intervention to decrease epilepsy-related stigma in an onchocerciasis-endemic area in Mahenge, Tanzania: A pilot study

A high burden of epilepsy has been reported in sub-Saharan Africa (SSA) particularly in onchocerciasis endemic areas. To improve the quality of life of persons with epilepsy (PWE) in Mahenge, an onchocerciasis-endemic area in Tanzania, we established peer support groups (PSG) in two out of four rural villages (Mdindo, Msogezi, Mzelezi and Sali). One year later (between February and July 2020), we carried out a cross-sectional survey among PWE and their caregivers in the four rural villages with the aim of comparing perceived stigma among PWE in study sites with and without PSG. Perceived stigma was measured using the validated Kilifi stigma scale of epilepsy (KSSE), whose total score ranges from 0-30. A generalized linear mixed regression model was used to identify factors associated with high stigma scores. A total of 161 PWE participated in the study; 76 (47.2%) resided in villages where a PSG intervention was implemented. The overall mean stigma score was 3.7 ± 4.6, with no significant difference between villages with and without PSG (p = 0.537). Only one PWE (0.6%) scored above 20 (very high perceived stigma). Experiencing more seizures during the past week (Coef = 1.013 [0.568, 1.457]), having attended school (Coef = 1.821 0.345, 3.297], and a history of physical abuse (Coef = 3.200 [0.574, 5.827]) were associated with higher stigma scores. Perceived stigma in rural villages in Mahenge is a major public health problem. A follow-up study is needed to determine the medium- to long-term effect of the PSG intervention on perceived epilepsy-related stigma.

Exploring the prevalence and profile of epilepsy across Europe using a standard retrospective chart review: Challenges and opportunities

OBJECTIVE

This study aimed to determine the prevalence of epilepsy in four European countries (Austria, Denmark, Ireland, and Romania) employing a standard methodology. The study was conducted under the auspices of ESBACE (European Study on the Burden and Care of Epilepsy).

METHODS

All hospitals and general practitioners serving a region of at least 50 000 persons in each country were asked to identify patients living in the region who had a diagnosis of epilepsy or experienced a single unprovoked seizure. Medical records were accessed, where available, to complete a standardized case report form. Data were sought on seizure frequency, seizure type, investigations, etiology, comorbidities, and use of antiseizure medication. Cases were validated in each country, and the degree of certainty was graded as definite, probable, or suspect cases.

RESULTS

From a total population of 237 757 in the four countries, 1988 (.8%) patients were identified as potential cases of epilepsy. Due to legal and ethical issues in the individual countries, medical records were available for only 1208 patients, and among these, 113 had insufficient clinical information. The remaining 1095 cases were classified as either definite (n = 706, 64.5%), probable (n = 191, 17.4%), suspect (n = 153, 14.0%), or not epilepsy (n = 45, 4.1%).

SIGNIFICANCE

Although a precise prevalence estimate could not be generated from these data, the study found a high validity of epilepsy classification among evaluated cases (95.9%). More generally, this study highlights the significant challenges facing epidemiological research methodologies that are reliant on patient consent and retrospective chart review, largely due to the introduction of data protection legislation during the study period. Documentation of the epilepsy diagnosis was, in some cases, relatively low, indicating a need for improved guidelines for assessment, follow-up, and documentation. This study highlights the need to address the concerns and requirements of recruitment sites to engage in epidemiological research.

Epilepsy in the Sanaga-Mbam valley, an onchocerciasis-endemic region in Cameroon: electroclinical and neuropsychological findings

OBJECTIVE

Epilepsy is highly prevalent in onchocerciasis-endemic African regions. Various types of epilepsy have been described in such regions based essentially on clinical characteristics.

METHODS

We conducted a clinical, neurophysiological and neuropsychological study of epilepsy in the onchocerciasis-endemic region of Ntui, Sanaga-Mbam area, Cameroon.

RESULTS

One hundred and eighty-seven persons with presumed epilepsy were recruited in an epilepsy clinic in Ntui. Epilepsy was clinically confirmed in 144 (79%) subjects, 69 (46.0%) of them met the onchocerciasis-associated epilepsy (OAE) criteria, and 51 of 106 tested (48.1%) presented Ov16 antibodies. Electroencephalograms (EEG) were recorded in 91 participants, of which 36 (33%) were considered abnormal and 27 of 36 (75%) revealed bifrontotemporal spike and slow waves. Concerning the neuropsychological evaluation, 29% showed severe global cognitive impairment, 28% severe episodic memory impairment, and 66% severe frontal cognitive impairment. Half of the persons with epilepsy (PWE) suffered from a mental disorder.

SIGNIFICANCE

In PWE in the Sanaga-Mbam area in Cameroon, we observed EEG patterns similar to those described among persons with OAE, including nodding syndrome in other onchocerciasis-endemic areas. Most PWE presented with severe cognitive impairment. We hypothesize that onchocerciasis may induce neurocognitive disorders and epilepsy via a mechanism that involves mainly the frontal and temporal regions of the brain.

Epilepsy in a health district in North-West Cameroon: Clinical characteristics and treatment gap

INTRODUCTION

Epilepsy is a common yet misunderstood condition in Cameroon, including in the Batibo Health district.

METHODS

This cross-sectional study describes epilepsy clinical characteristics, the treatment gap, and associated factors in a rural district in Cameroon. After screening for epilepsy using a door-to-door survey, physicians confirmed suspected cases of epilepsy. Detailed information on the medical, seizure, and treatment history was collected from everyone with epilepsy, followed by a general and neurological examination.

RESULTS

We diagnosed 546 people with active epilepsy (at least one seizure in the previous 12 months). The mean age of people with active epilepsy was 25.2 years (SD: 11.1). The mean age at first seizure was 12.5 years (SD: 8.2). Convulsive seizures (uncertain whether generalized or focal) were the most common seizure types (60%), while 41% had focal-onset seizures. About 60% of people had seizures at least monthly. One-quarter of participants had had at least one episode of status epilepticus. Anti-seizure medication (ASM) was taken by 85%, but most were receiving inappropriate treatment or were non-adherent, hence the high treatment gap (80%). Almost a third had had seizure-related injuries. Epilepsy was responsible for low school attendance; 74% of school dropouts were because of epilepsy.

CONCLUSION

The high proportion of focal-onset seizures suggests acquired causes (such as neurocysticercosis and onchocerciasis, both endemic in this area). The high epilepsy treatment gap and the high rates of status epilepticus and epilepsy-related injuries underscore the high burden of epilepsy in this rural Cameroonian health district.

Incidence and prevalence of epilepsy and associated factors in a health district in North-West Cameroon: A population survey

This population-based cross-sectional survey with a follow-up case-control study assessed the prevalence, incidence, and risk factors for epilepsy in a rural health district in the North-West Region of Cameroon. Community-based epilepsy screening targeted all inhabitants, six years and older, in all 16 health areas in the Batibo Health District. During door-to-door visits, trained fieldworkers used a validated questionnaire to interview consenting household heads to screen for epilepsy in eligible residents. Trained physicians subsequently assessed people with suspected seizures. After clinical assessment, they confirmed or refuted the diagnosis and estimated the date of epilepsy onset. A trained nurse interviewed people with epilepsy and randomly selected healthy individuals, obtaining relevant demographic details and information on exposure to risk factors for epilepsy. Out of 36,282 residents screened, 524 had active epilepsy. The age-standardized prevalence of active epilepsy was 33.9/1,000 (95% CI: 31.0-37.1/1,000). We estimated the one-year age-standardized epilepsy incidence at 171/100,000 (95%CI: 114.0-254.6). Active epilepsy prevalence varied widely between health areas, ranging between 12 and 75 per 1,000. The peak age-specific prevalence was in the 25-34 age group. In adults, multivariate analysis showed that having a relative with epilepsy was positively associated with epilepsy. Epilepsy characteristics in this population, geographical heterogeneity, and the age-specific prevalence pattern suggest that endemic neurocysticercosis and onchocerciasis may be implicated. Further investigations are warranted to establish the full range of risk factors for epilepsy in this population.

Epidemiology of Epilepsy in Low- and Middle-Income Countries: Experience of a Standardized Questionnaire over the Past Two Decades

INTRODUCTION

Epilepsy affects >50 million people worldwide, with 80% of them living in low- and middle-income countries (LMICs). Studies with a standardized methodology are required to obtain comparable data on epilepsy and implement health policies in order to reduce the treatment gap and improve the diagnosis and management of epilepsy. In 2000, following the guidelines of the International League Against Epilepsy (ILAE), the "questionnaire for investigation of epilepsy in tropical countries" (IENT questionnaire) was developed to promote epidemiological surveys on epilepsy using a standard methodology. This study aims to describe how, when, where, and why the IENT questionnaire has been used through epidemiological studies on epilepsy over the last 2 decades and to acquire users' opinions about the tool.

METHODS

Studies that used the IENT questionnaire were searched through international and local bibliographic databases, including the gray literature. An online survey was carried out, including a snowball effect. Original research studies were included. Characteristics of the studies and populations and general information on the instrument and its use were collected.

RESULTS

Eighty-two documents were selected referring to 61 studies that were mostly carried out on the African continent (n = 54). Most of them aimed to determine the prevalence (n = 31) and associated factors (n = 28) of epilepsy in LMICs. Among the 61 studies, 35 were population-based, and 30 included both adults and children. A methodological heterogeneity was found between studies, and in cases where the IENT questionnaire alone did not ensure complete data collection, other tools were used concomitantly (n = 40).

DISCUSSION/CONCLUSION

Over the last 2 decades, the IENT questionnaire has been continuously used in different LMICs. This result favors its promotion and updating, with the inclusion of new topics related to epilepsy (e.g., comorbidities, quality of life, and stigma), current ILAE guidelines, and digital versions.

In pursuit of a cure: The plural therapeutic landscape of onchocerciasis-associated epilepsy in Cameroon - A mixed methods study

BACKGROUND

A high prevalence of epilepsy has been observed in several onchocerciasis-endemic villages in the Sanaga River basin, Cameroon. Recent studies suggest that ivermectin, a drug that is distributed annually with the aim of eliminating onchocerciasis, may have a protective effect against acquiring onchocerciasis-associated epilepsy (OAE). This study, therefore, provides an in-depth understanding of both the complex therapeutic landscape for epilepsy as well as the experiences related to the 'community-directed treatment with ivermectin' (CDTI) campaign in order to identify a more trenchant path forward in the fight against epilepsy.

METHODOLOGY/PRINCIPAL FINDINGS

Based on a mixed methods study combining a qualitative strand with a quantitative survey, we found that epilepsy was perceived to have had an epidemic emergence in the past and was still considered an important health issue in the study area. Socio-economic status, availability and accessibility of drugs and practitioners, as well as perceived aetiology shaped therapeutic itineraries for epilepsy, which included frequenting (in)formal biomedical health care providers, indigenous and/or faith healing practitioners. Ivermectin uptake for onchocerciasis was generally well known and well regarded. The CDTI faced structural and logistical bottlenecks undermining equal access and optimal adherence to the drug.

CONCLUSIONS/SIGNIFICANCE

Locally accessible, uninterrupted, sustainable and comprehensive health-service delivery is essential to help alleviate the epilepsy burden on afflicted households. Addressing structural challenges of CDTI and communicating the potential link with epilepsy to local populations at risk could optimize the uptake of this potentially significant tool in OAE prevention.

Onchocerciasis in tropical neurology: A scoping review

BACKGROUND

Onchocerciasis is a serious problem in tropical areas. The role of the parasite as a factor associated with neurological diseases needs to be addressed because it might involve a reduction of the risk via elimination strategies. We performed a systematic scoping review to identify available studies on this association and put into perspective the different methodological approaches for interpreting the evidence.

METHODOLOGY

A literature search was conducted using MEDLINE (Pubmed) through October 1, 2020. We included all the studies evaluating the association between onchocerciasis and four neurological diseases (epilepsy, nodding syndrome, Nakalanga syndrome, and encephalitis) in tropical countries. A descriptive and critical summary of the results was conducted to provide an overview of the findings.

RESULTS

Overall, 161 articles were identified in the literature search. After full-length examination, we included twelve articles for epilepsy and three for nodding syndrome. Two meta-analyses of case-control studies found a modest strength of the association between O. volvulus and epilepsy. Recent meta-analyses and original studies support a significant association. Epidemiological studies suggest an association between onchocerciasis and nodding syndrome, however, the level of evidence from case-control studies was relatively low. No measure of association was reported for Nakalanga syndrome. There was no specific study on the association between O. volvulus and encephalitis.

CONCLUSION

The association between onchocerciasis and epilepsy seems increasingly likely. However, there are still many unanswered questions about the different clinical presentations of this epilepsy. Strong international collaboration is essential to improve our understanding of risk factors and physiopathological mechanisms of these intriguing conditions.

Onchocerca volvulus and epilepsy: A comprehensive review using the Bradford Hill criteria for causation

BACKGROUND

The possibility that onchocerciasis may cause epilepsy has been suggested for a long time, but thus far, an etiological link has not been universally accepted. The objective of this review is to critically appraise the relationship between Onchocerca volvulus and epilepsy and subsequently apply the Bradford Hill criteria to further evaluate the likelihood of a causal association.

METHODS

PubMed and gray literature published until September 15, 2020, were searched and findings from original research were synthesized. Adherence to the 9 Bradford Hill criteria in the context of onchocerciasis and epilepsy was determined to assess whether the criteria are met to strengthen the evidence base for a causal link between infection with O. volvulus and epilepsy, including the nodding syndrome.

RESULTS

Onchocerciasis as a risk factor for epilepsy meets the following Bradford Hill criteria for causality: strength of the association, consistency, temporality, and biological gradient. There is weaker evidence supporting causality based on the specificity, plausibility, coherence, and analogy criteria. There is little experimental evidence. Considering the Bradford Hill criteria, available data suggest that under certain conditions (high microfilarial load, timing of infection, and perhaps genetic predisposition), onchocerciasis is likely to cause epilepsy including nodding and Nakalanga syndromes.

CONCLUSION

Applying the Bradford Hill criteria suggests consistent epidemiological evidence that O. volvulus infection is a trigger of epilepsy. However, the pathophysiological mechanisms responsible for seizure induction still need to be elucidated.

Community-based door to door census of suspected people living with epilepsy: empowering community drug distributors to improve the provision of care to rural communities in Cameroon

Background

Epilepsy is a severe neurological disorder with huge psychological, social, and economic consequences, including premature deaths and loss of productivity. Sub-Saharan Africa carries the highest burden of epilepsy. The management of epilepsy in Cameroon remains unsatisfactory due to poor identification of cases and a limited knowledge of the distribution of the disease. The objective of this study was to determine whether community drug distributors (CDDs) - volunteers selected by their communities to distribute ivermectin against onchocerciasis and who have been proven efficient to deliver other health interventions such as insecticide-treated bed nets to prevent malaria, vitamin A tablets, and albendazole to treat soil transmitted helminthiasis - can be used to reliably identify people living with epilepsy to promote better management of cases.

Methods

This study was carried out in three health Districts in Cameroon. An exhaustive house to house census was carried out by trained CDDs under the supervision of local nurses. In each household, all suspected cases of epilepsy were identified. In each health district, five communities were randomly selected for a second census by trained health personnel (research team). The results of the two censuses were compared for verification purposes.

Results

A total of 53,005 people was registered in the 190 communities surveyed with 794 (1.4%) individuals identified as suspected cases of epilepsy (SCE) by the CDDs. In the 15 communities where the SCE census was verified, the average ratio between the number of suspected cases of epilepsy reported in a community by the research team and that reported by the CDDs was 1.1; this ratio was < 0.8 and > 1.2 in 6 communities.

Conclusions

The results of this study suggest that CDDs, who are present in about 200,000 communities in 31 Sub Saharan African countries where onchocerciasis is endemic, can be successfully used to assess epilepsy prevalence, and therefore map epilepsy in many African countries.

Comorbidities of epilepsy in low and middle-income countries: systematic review and meta-analysis

Epilepsy is a major public health concern in low and middle-income countries (LMICs) and comorbidities aggravate the burden associated with the disease. The epidemiology of these comorbidities has not been well described, although, identifying the main comorbidities of epilepsy, and their relative importance, is crucial for improving the quality of care. Comorbidities were defined as disorders coexisting with or preceding epilepsy, or else compounded or directly attributed to epilepsy or to its treatment. A meta-analysis of the proportion of main comorbidities by subcontinent as well as overall was also conducted. Out of the 2,300 papers identified, 109 from 39 countries were included in this systematic review. Four groups of comorbidities were identified: parasitic and infectious diseases (44% of comorbid conditions), somatic comorbidities (37%), psychosocial (11%), as well as psychiatric comorbidities (8%). Heterogeneity was statistically significant for most variables then random effect models were used. The most frequently studied comorbidities were: neurocysticercosis (comorbid proportion: 23%, 95% CI: 18-29), head trauma (comorbid proportion: 9%, 95% CI: 5-15) malnutrition (comorbid proportion: 16%, 95% CI: 28-40), stroke (comorbid proportion: 1.3%, 95% CI: 0.2-7.0), and discrimination for education (comorbid proportion: 34%, 95% CI: 28-40). Many comorbidities of epilepsy were identified in LMICs, most of them being infectious.

Stigma and epilepsy in onchocerciasis-endemic regions in Africa: a review and recommendations from the onchocerciasis-associated epilepsy working group

BACKGROUND

In onchocerciasis-endemic areas, particularly in those with a sub-optimal onchocerciasis control programme, a high prevalence of epilepsy is observed. Both onchocerciasis and epilepsy are stigmatizing conditions. The first international workshop on onchocerciasis-associated epilepsy (OAE) was held in Antwerp, Belgium (12-14 October 2017) and during this meeting, an OAE alliance was established. In this paper, we review what is known about epilepsy-associated stigma in onchocerciasis-endemic regions, and present the recommendations of the OAE alliance working group on stigma.

MAIN BODY

For this scoping review, literature searches were performed on the electronic databases PubMed, Scopus and Science Direct using the search terms "epilepsy AND onchocerciasis AND stigma". Hand searches were also undertaken using Google Scholar, and in total seven papers were identified that addressed epilepsy-related stigma in an onchocercisasis-endemic area. Due to the limited number of published research papers on epilepsy-associated stigma in onchocerciasis-endemic areas, other relevant literature that describes important aspects related to stigma is discussed. The thematic presentation of this scoping review follows key insights on the barriers to alleviating the social consequences of stigma in highly affected onchocerciasis-endemic areas, which were established by experts during the working group on stigma and discrimination at the first international workshop on OAE. These themes are: knowledge gaps, perceived disease aetiology, access to education, marriage restrictions, psycho-social well-being, burden on the care-giver and treatment seeking behaviour. Based on the literature and expert discussions during the OAE working group on stigma, this paper describes important issues regarding epilepsy-related stigma in onchocerciasis-endemic regions and recommends interventions that are needed to reduce stigma and discrimination for the improvement of the psycho-social well-being of persons with epilepsy.

CONCLUSIONS

Educating healthcare workers and communities about OAE, strengthening onchocerciasis elimination programs, decreasing the anti-epileptic treatment gap, improving the care of epilepsy-related injuries, and prioritising epilepsy research is the way forward to decreasing the stigma associated with epilepsy in onchocerciasis-endemic regions.

Identifying areas for improvement in epilepsy management in developing countries: An experience of neurocooperation in Cameroon

INTRODUCTION

Epilepsy is especially prevalent in developing countries: incidence and prevalence rates are at least twice as high as in our setting. Epilepsy is also highly stigmatised, and few resources are available for its management.

MATERIAL AND METHODS

We performed a descriptive observational study in December 2016, distributing a questionnaire on epilepsy management to healthcare professionals from 3 different hospitals in Cameroon. Data are presented as means or percentages.

RESULTS

Thirty-eight healthcare providers participated in the survey; 42.1% were female and mean age was 40.1 years (range, 22-62). Regarding the causes of epilepsy, 68.4% considered it a psychiatric condition, 34.2% a degenerative disease, 28.9% a hereditary condition, and 21.1% secondary to infection. In terms of management, 23.7% considered that thorough clinical history is sufficient to establish a diagnosis. Only 60.5% considered the clinical interview to be important for diagnosis, 52.6% considered EEG to be necessary, and 28.9% considered laboratory analyses to be important. Only 13.2% mentioned neuroimaging. In the treatment of pregnant women, 36.8% recommended folic acid supplementation, 65.8% believed antiepileptic treatment should be maintained, and only 39.5% recommended breastfeeding. Concerning treatment, the participants knew a mean of 2 antiepileptic drugs: phenobarbital was the best known (81.6%), followed by carbamazepine (55.3%) and valproic acid (28.9%).

CONCLUSIONS

There is a need among healthcare professionals for education and information on the disease, its diagnosis, and management options, in order to optimise management and consequently improve patients' quality of life.

High prevalence of epilepsy in an onchocerciasis endemic health zone in the Democratic Republic of the Congo, despite 14 years of community-directed treatment with ivermectin: A mixed-method assessment

•

A high epilepsy prevalence in the Aketi health zone was observed despite 14 years of community-directed treatment with ivermectin.

•

The high prevalence of OV16 antibodies in children is indicative of high ongoing onchocerciasis transmission.

•

High onchocerciasis transmission is the consequence of high exposure to blackflies and low intake of ivermectin.

•

Head nodding seizures were observed in 13.8% of the persons with epilepsy.

•

Ivermectin coverage needs to be increased and bi-annual distribution should be considered.

Objectives

To investigate the reasons for the high prevalence of epilepsy (>6%) discovered in 2015 in the Aketi health zone in the north of the Democratic Republic of the Congo.

Methods

Persons with epilepsy (PWE) diagnosed in a door-to-door survey in 2015 were traced and re-examined in 2017 by a neurologist. Confirmed PWE were paired with matched controls. For onchocerciasis assessment, children 7–10 years old were tested for IgG4 Onchocerca volvulus (OV16) antibodies, a rapid epidemiological mapping of onchocerciasis (REMO) study was performed, and ivermectin coverage was investigated.

Results

Forty-three (61.4%) previously diagnosed PWE were traced; the neurologist confirmed the epilepsy diagnosis in all of them. The overall OV16 positivity rate was 64.5%. Poor ivermectin coverage (55.9%) and a high prevalence of onchocercal nodules (>70%) were observed. The prevalence of epilepsy was 5.7% in Aketi rural town, with nine PWE (13.8%) experiencing head nodding seizures. A case-control study showed that PWE had lower body weight and higher ivermectin coverage in 2017 than healthy controls.

Conclusions

The high prevalence of epilepsy in the Aketi health zone, despite 14 years of community-directed treatment with ivermectin (CDTI), was found to be associated with high onchocerciasis transmission and low ivermectin use. An awareness programme to increase ivermectin coverage and the introduction of a bi-annual CDTI programme should be considered.

An estimation of global volume of surgically treatable epilepsy based on a systematic review and meta-analysis of epilepsy

OBJECTIVE

Epilepsy is one of the most common neurological disorders, yet its global surgical burden has yet to be characterized. The authors sought to compile the most current epidemiological data to quantify global prevalence and incidence, and estimate global surgically treatable epilepsy. Understanding regional and global epilepsy trends and potential surgical volume is crucial for future policy efforts and resource allocation.

METHODS

The authors performed a systematic literature review and meta-analysis to determine the global incidence, lifetime prevalence, and active prevalence of epilepsy; to estimate surgically treatable epilepsy volume; and to evaluate regional trends by WHO regions and World Bank income levels. Data were extracted from all population-based studies with prespecified methodological quality across all countries and demographics, performed between 1990 and 2016 and indexed on PubMed, EMBASE, and Cochrane. The current and annual new case volumes for surgically treatable epilepsy were derived from global epilepsy prevalence and incidence.

RESULTS

This systematic review yielded 167 articles, across all WHO regions and income levels. Meta-analysis showed a raw global prevalence of lifetime epilepsy of 1099 per 100,000 people, whereas active epilepsy prevalence is slightly lower at 690 per 100,000 people. Global incidence was found to be 62 cases per 100,000 person-years. The meta-analysis predicted 4.6 million new cases of epilepsy annually worldwide, a prevalence of 51.7 million active epilepsy cases, and 82.3 million people with any lifetime epilepsy diagnosis. Differences across WHO regions and country incomes were significant. The authors estimate that currently 10.1 million patients with epilepsy may be surgical treatment candidates, and 1.4 million new surgically treatable epilepsy cases arise annually. The highest prevalences are found in Africa and Latin America, although the highest incidences are reported in the Middle East and Latin America. These regions are primarily low- and middle-income countries; as expected, the highest disease burden falls disproportionately on regions with the fewest healthcare resources.

CONCLUSIONS

Understanding of the global epilepsy burden has evolved as more regions have been studied. This up-to-date worldwide analysis provides the first estimate of surgical epilepsy volume and an updated comprehensive overview of current epidemiological trends. The disproportionate burden of epilepsy on low- and middle-income countries will require targeted diagnostic and treatment efforts to reduce the global disparities in care and cost. Quantifying global epilepsy provides the first step toward restructuring the allocation of healthcare resources as part of global healthcare system strengthening.

Impact of 19 years of mass drug administration with ivermectin on epilepsy burden in a hyperendemic onchocerciasis area in Cameroon

BACKGROUND

Surveys conducted in 1991-1992 in the Mbam Valley (Cameroon) revealed that onchocerciasis was highly endemic, with community microfilarial loads (CMFL) > 100 microfilariae/snip in some villages. Also in 1991-1992, a survey of suspected cases of epilepsy (SCE) found 746 SCE using a questionnaire administered to individuals identified by key informants, with prevalences reaching 13.6% in some communities. From 1998, annual community-directed treatment with ivermectin (CDTI) was implemented to control onchocerciasis. In 2017, a door-to-door household survey was conducted in three of the villages visited in 1991-1992, using a standardized 5-item epilepsy screening questionnaire.

RESULTS

In 2017, a total of 2286 individuals living in 324 households were screened (582 in Bayomen, 553 in Ngongol and 1151 in Nyamongo) and 112 SCE were identified (4.9%). Neurologists examined 92 of these SCE and confirmed the diagnosis of epilepsy for 81 of them (3.5%). Between the surveys in 1991-1992 and 2017, the prevalence of SCE decreased from 13.6% to 2.5% in Bayomen (P = 0.001), from 8.7% to 6.6% in Ngongol (P = 0.205) and from 6.4% to 5.4% in Nyamongo (P = 0.282). The median age of SCE shifted from 20 (IQR: 12-23) to 29 years (IQR: 18-33; P = 0.018) in Bayomen, from 16 (IQR: 12-21) to 26 years (IQR: 21-39; P < 0.001) in Ngongol and from 16 (IQR: 13-19) to 24 years (IQR: 19-32; P < 0.001) in Nyamongo. The proportions of SCE aged < 10, 10-19, 20-29 and ≥ 30 years shifted from 9.5, 58.3, 25.0 and 7.1% in 1991-1992 to 2.7, 20.5, 39.3 and 37.5% in 2017, respectively.

CONCLUSIONS

SCE prevalence decreased overall between 1991-1992 and 2017. The age shift observed is probably due to a decrease in the number of new cases of epilepsy resulting from the dramatic reduction of Onchocerca volvulus transmission after 19 years of CDTI.

Clinical presentations of onchocerciasis-associated epilepsy (OAE) in Cameroon

BACKGROUND

A high prevalence of epilepsy has been observed in several onchocerciasis-endemic countries, including Cameroon. However, little is known on the clinical presentations of the affected persons with epilepsy (PWE). A community-based study was conducted with the aim of describing the spectrum of seizures in selected onchocerciasis-endemic villages in Cameroon and documenting relevant medical history in patients with onchocerciasis-associated epilepsy (OAE).

METHODS

We carried out door-to-door surveys in 5 onchocerciasis-endemic villages in Cameroon and recruited all consenting PWE. Epilepsy was diagnosed using a 2-step approach consisting of the administration of a standardized 5-item questionnaire followed by confirmation of the suspected cases by a neurologist. Onchocerciasis-associated epilepsy was defined as ≥2 seizures without an obvious cause, starting between the ages of 3-18 years in previously healthy persons having resided for at least 3 years in an onchocerciasis-endemic area. Ivermectin use by PWE was verified. Seizure history, relevant past medical, and family history, as well as neurological findings, were noted.

RESULTS

In all, 156 PWE were recruited in the 5 villages. The modal age group for epilepsy onset was 10-14 years. The diagnostic criteria for OAE were met by 93.2% of the PWE. Participants had one or more of the following seizure types: generalized tonic-clonic seizures (89.1%), absences (38.5%), nodding (21.8%), focal nonmotor (7.7%), and focal motor seizures (1.9%). One case (0.6%) with the "Nakalanga syndrome" was identified. More than half (56.4%) of PWE had at least one seizure per month. In one village, 56.2% of PWE had onchocercal skin lesions.

CONCLUSION

People with epilepsy in onchocerciasis-endemic villages in Cameroon present with a wide clinical spectrum including nodding seizures and Nakalanga features. A great majority of participants met the diagnostic criteria for OAE, suggesting that better onchocerciasis control could prevent new cases. Epilepsy management algorithms in these areas must be adjusted to reflect the varied seizure types.

Epidemiology of onchocerciasis-associated epilepsy in the Mbam and Sanaga river valleys of Cameroon: impact of more than 13 years of ivermectin

BACKGROUND

A high epilepsy prevalence has been reported in several onchocerciasis-endemic villages along the Mbam and Sanaga river valleys in Cameroon, including Bilomo and Kelleng. We sought to determine the prevalence of epilepsy in these two villages following more than 13 years of community-directed treatment with ivermectin (CDTI).

METHODS

Door-to-door surveys were performed on the entire resident population in the villages in August 2017 and January 2018. Epilepsy was diagnosed using a 2-step approach: administration of a standardized 5-item questionnaire followed by confirmation by a neurologist. Previously published diagnostic criteria for onchocerciasis-associated epilepsy (OAE) were used. Ov16 serology was done for children aged 7-10 years to assess onchocerciasis transmission. Findings were compared with previous data from these two villages.

RESULTS

A total of 1525 individuals (1321 in Bilomo and 204 in Kelleng) in 233 households were surveyed in both villages. The crude prevalence of epilepsy was 4.6% in Bilomo (2017) and 7.8% in Kelleng (2018), including 12 (15.6% of cases) persons with epilepsy (PWE) with nodding seizures. The age and sex-standardized prevalence in Kelleng decreased from 13.5% in 2004 to 9.3% in 2018 (P < 0.001). The median age of PWE shifted from 17 (IQR: 12-22) years to 24 (IQR: 20-30) years in Bilomo (P < 0.001); and slightly from 24 (IQR: 14-34) years to 28 (IQR: 21.25-36.75) years in Kelleng (P = 0.112). Furthermore, 47.6% of all tested children between 7 and 10 years had Ov16 antibodies.

CONCLUSIONS

There is a decrease in epilepsy prevalence after 13 years and more of CDTI in both villages. The age-shift observed in PWE suggests that ivermectin may prevent OAE in younger residents. Ov16 seropositivity in children indicates ongoing onchocerciasis transmission possibly due to suboptimal control measures. Our findings support the existence of OAE in Cameroon and highlight the need to strengthen onchocerciasis elimination programs.

High prevalence of onchocerciasis-associated epilepsy in villages in Maridi County, Republic of South Sudan: A community-based survey

PURPOSE

To determine the prevalence and incidence of epilepsy in an onchocerciasis endemic region of South Sudan.

METHODS

In May 2018, a door-to-door household survey was conducted in 8 study sites in an onchocerciasis endemic area in Maridi County.

RESULTS

A total of 2511 households agreed to participate in the study, corresponding to 17,652 individuals. An epilepsy screening questionnaire identified 799 persons suspected to have epilepsy (4.5%); in 736 of the 766 persons (96.1%) seen by a clinical officer the diagnosis of epilepsy was confirmed. Adding 38 persons who were not seen but with a positive answer to a combination of screening questions, 774 persons (4.4%) had epilepsy. Epilepsy prevalence was highest in the 11-20 age group (10.5%); 66 persons with epilepsy (PWE) developed their first seizures in the year preceding the survey (annual incidence = 373.9/100.000). Neurocysticercosis cannot explain the high epilepsy prevalence since no pigs are kept in the area. Independent risk factors for epilepsy included male gender, belonging to a "permanent household" and a farming family, and living in a village bordering the Maridi River. Only 7209 (40.8%) of the population took ivermectin in 2017.

CONCLUSION

A very high prevalence and incidence of epilepsy was observed in several villages in Maridi County located close to the Maridi River and the Maridi dam. Urgent action is needed to prevent children in Maridi County from developing OAE by strengthening the onchocerciasis elimination program.

Is nodding syndrome in northern Uganda linked to consumption of mycotoxin contaminated food grains?

OBJECTIVE

Nodding syndrome (NS) is a type of epilepsy characterized by repeated head-nodding seizures that appear in previously healthy children between 3 and 18 years of age. In 2012, during a WHO International Meeting on NS in Kampala, Uganda, it was recommended that fungal contamination of foods should be investigated as a possible cause of the disease. We therefore aimed to assess whether consumption of fungal mycotoxins contributes to NS development.

RESULTS

We detected similar high levels of total aflatoxin and ochratoxin in mostly millet, sorghum, maize and groundnuts in both households with and without children with NS. Furthermore, there was no significant association between concentrations of total aflatoxin, ochratoxin and doxynivalenol and the presence of children with NS in households. In conclusion, our results show no supporting evidence for the association of NS with consumption of mycotoxins in contaminated foods.

Burden of onchocerciasis-associated epilepsy: first estimates and research priorities

BACKGROUND

Since the 1990s, evidence has accumulated of an increased prevalence of epilepsy in onchocerciasis-endemic areas in Africa as compared to onchocerciasis-free areas. Although the causal relationship between onchocerciasis and epilepsy has yet to be proven, there is likely an association. Here we discuss the need for disease burden estimates of onchocerciasis-associated epilepsy (OAE), provide them, detail how such estimates should be refined, and discuss the socioeconomic impact of OAE, including a cost-estimate for anti-epileptic drugs.

MAIN BODY

Providing OAE burden estimates may aid prevention of epilepsy in onchocerciasis- endemic areas by inciting and informing collaboration between onchocerciasis control programmes and mental health services. Epilepsy not only massively impacts the health of those affected, but it also carries a high socioeconomic burden for the households and communities involved. We used previously published geospatial estimates of onchocerciasis in Africa and a separately published logistic regression model quantifying the association between onchocerciasis and epilepsy to estimate the number of OAE cases. We then applied disability weights for epilepsy to quantify the burden in terms of years of life lived with disability (YLD) and estimate the cost of treatment. We estimate that in 2015 roughly 117 000 people were affected by OAE across onchocerciasis-endemic areas previously under the African Programme for Onchocerciases control (APOC) mandate where OAE has ever been reported or suspected, and another 264 000 persons in onchocerciasis-endemic areas where OAE has never been investigated before. The total number of YLDs due to OAE was 39 300 and 88 700 in these areas respectively, based on a weighted mean disability weight of 0.336. The burden of OAE is approximately 13% of the total YLDs attributable to onchocerciasis and 10% of total YLDs attributable to epilepsy. We estimated that by 2015 the total costs of treatment with anti-epileptic drug for OAE cases would have been a minimum of 12.4 million US$.

CONCLUSIONS

These estimates suggest a considerable health, social and economic burden of OAE in Africa. The treatment and care for people with epilepsy, especially in hyperendemic onchocerciasis areas with high epilepsy prevalence thus requires more financial and human resources.

Onchocerciasis-Associated Epilepsy, an Additional Reason for Strengthening Onchocerciasis Elimination Programs

A high prevalence of epilepsy has been observed in onchocerciasis-endemic regions with high onchocerciasis transmission. Recent epidemiological studies suggest that Onchocerca volvulus infection is the trigger causing the seizures, which appear in previously healthy children between the ages of 3 and 18 years. Persons with onchocerciasis-associated epilepsy present with a wide spectrum of seizures, including atonic and myoclonic neck seizures; but also absences and most frequently generalized tonic-clonic seizures. Often individuals present with intellectual disabilities and psychiatric disorders and occasionally with 'Nakalanga' features such as severe stunting with delayed or absent external signs of sexual development. Onchocerciasis-associated epilepsy, because of its importance as a public health problem, is an additional reason for strengthening onchocerciasis elimination programs.

The epidemiological and clinical characteristics study on epilepsy in 8 ethnic groups of China

To survey the epidemiological characteristics and clinical features on epilepsy in eight ethnic groups in Yunnan province of China.

METHODES

The investigation was based on the WHO questionnaire and ICBERG screening questionnaire. This study was performed through random cluster sampling and door-to-door survey.

RESULTS

A total of 76,302 individuals from eight ethnic groups were surveyed. The crude prevalence of epilepsy ranged from 1.2/1000 to 6.5/1000 in the eight ethnic groups, and the age-adjusted prevalence of epilepsy was from 2.1/1000 to 7.3/1000. The prevalence of active epilepsy varied from 1.0/1000 to 5.2/1000 in the eight ethnic groups, and the age-adjusted prevalence of active epilepsy was from 1.8/1000 to 6.7/1000. The age peak for seizures was below twenty, the patients of 61.1%-95.0% suffered from generalized seizures and 5%-21.2% had partial seizures. More than 60% of the cases in five ethnic groups, and the frequency of seizures were more than 10 events per year. More than 50% in other three ethnic groups, and the seizures had occurred less than 10 events per year. The treatment gap for active epilepsy ranged from 43.7% to 100.0% among the eight ethnic groups, while the natural remission rate varied from 5.6% to 21.0%.

CONCLUSION

There were both disparity and similarity in the epidemiological and clinical features of epilepsy in different ethnic group communities.

Epilepsy as a health problem among school children in Turaif, Northern Saudi Arabia, 2017

BACKGROUND

Epilepsy is the most common serious neurological disorder and is one of the world's most prevalent non-communicable diseases. There are no recently published data on the prevalence of epilepsy in school children in Northern Saudi Arabia.

OBJECTIVE

This study was conducted to determine the prevalence of epilepsy and to show some of its risk factors in school children and adolescents (6-18 years) in Turaif city, Northern Saudi Arabia.

METHODS

This, population-based, cross-sectional study was conducted in Turaif city, over a 6-month period, from July 2016 to January 2017. It included pupils aged 6 to18 years in all primary, preparatory and secondary schools in Turaif city. Multi-stage sampling was employed. A designated structured questionnaire was completed for each patient and included the patient's history, clinical examination, investigations and medications. Data were analyzed by SPSS version 16, using Chi-Squared test and descriptive statistics.

RESULTS

Out of 1,230 children, 66 (5.5%) had epilepsy; 68.2% of them were males and 31.8% females (p=0.000). Consanguinity between parents plays a significant role where 59.1% of cases had parents who were cousins (p=0.000). Family history also had a significant effect as 68.2% of cases had epilepsy cases in their families (p=0.000).

CONCLUSION

Epilepsy prevalence among school children (6-18 years) in Turaif city is higher in males than females. Consanguinity and positive family history are important factors. Decision makers must take effective steps to limit the causes and risk factors of the problem.

Onchocerciasis-associated epilepsy: From recent epidemiological and clinical findings to policy implications

A high prevalence of epilepsy is reported in many onchocerciasis‐endemic regions. In this paper we discuss recent epidemiological and clinical aspects as well as public health implications of onchocerciasis‐associated epilepsy (OAE) and propose a strategy to reduce the burden of disease. OAE probably presents in a variety of clinical manifestations, including the nodding syndrome and the Nakalanga syndrome. The most common clinical presentation, however, is generalized (primarily tonic‐clonic) seizures. A characteristic of OAE is the onset of seizures between the ages of 3 and 18 years and clustering in certain families and villages close to rapid‐flowing black‐fly‐infested rivers. A strategy combining active surveillance for epilepsy with early treatment with antiepileptic drugs and prevention of onchocerciasis by increasing the geographical and therapeutic coverage of community‐directed treatment with ivermectin (CDTi) may considerably decrease the burden of disease.

Nakalanga Syndrome: Clinical Characteristics, Potential Causes, and Its Relationship with Recently Described Nodding Syndrome

Nakalanga syndrome is a condition that was described in Uganda and various other African countries decades ago. Its features include growth retardation, physical deformities, endocrine dysfunction, mental impairment, and epilepsy, amongst others. Its cause remains obscure. Nodding syndrome is a neurological disorder with some features in common with Nakalanga syndrome, which has been described mainly in Uganda, South Sudan, and Tanzania. It has been considered an encephalopathy affecting children who, besides head nodding attacks, can also present with stunted growth, delayed puberty, and mental impairment, amongst other symptoms. Despite active research over the last years on the pathogenesis of Nodding syndrome, to date, no convincing single cause of Nodding syndrome has been reported. In this review, by means of a thorough literature search, we compare features of both disorders. We conclude that Nakalanga and Nodding syndromes are closely related and may represent the same condition. Our findings may provide new directions in research on the cause underlying this neurological disorder.

Prevalence and incidence of epilepsy: A systematic review and meta-analysis of international studies

OBJECTIVE

To review population-based studies of the prevalence and incidence of epilepsy worldwide and use meta-analytic techniques to explore factors that may explain heterogeneity between estimates.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses standards were followed. We searched MEDLINE and EMBASE for articles published on the prevalence or incidence of epilepsy since 1985. Abstract, full-text review, and data abstraction were conducted in duplicate. Meta-analyses and meta-regressions were used to explore the association between prevalence or incidence, age group, sex, country level income, and study quality.

RESULTS

A total of 222 studies were included (197 on prevalence, 48 on incidence). The point prevalence of active epilepsy was 6.38 per 1,000 persons (95% confidence interval [95% CI] 5.57-7.30), while the lifetime prevalence was 7.60 per 1,000 persons (95% CI 6.17-9.38). The annual cumulative incidence of epilepsy was 67.77 per 100,000 persons (95% CI 56.69-81.03) while the incidence rate was 61.44 per 100,000 person-years (95% CI 50.75-74.38). The prevalence of epilepsy did not differ by age group, sex, or study quality. The active annual period prevalence, lifetime prevalence, and incidence rate of epilepsy were higher in low to middle income countries. Epilepsies of unknown etiology and those with generalized seizures had the highest prevalence.

CONCLUSIONS

This study provides a comprehensive synthesis of the prevalence and incidence of epilepsy from published international studies and offers insight into factors that contribute to heterogeneity between estimates. Significant gaps (e.g., lack of incidence studies, stratification by age groups) were identified. Standardized reporting of future epidemiologic studies of epilepsy is needed.

Nodding syndrome, western Uganda, 1994

Nodding syndrome (NS) is a poorly understood condition, which was delineated in 2008 as a new epilepsy syndrome. So far, confirmed cases of NS have been observed in three circumscribed African areas: southern Tanzania, southern Sudan, and northern Uganda. Case-control studies have provided evidence of an association between NS and infection with Onchocerca volvulus, but the causation of NS is still not fully clarified. We report a case of a 15-year old boy with head nodding seizures and other characteristic features of NS from an onchocerciasis endemic area in western Uganda, with no contiguity to the hitherto known areas. We suggest that the existence of NS should be systematically investigated in other areas.

Prevalence and risk factors for Active Convulsive Epilepsy in Kintampo, Ghana

INTRODUCTION

Epilepsy is common in sub-Saharan Africa, but there is little data in West Africa, to develop public health measures for epilepsy in this region.

METHODS

We conducted a three-stage cross-sectional survey to determine the prevalence and risk factors for active convulsive epilepsy (ACE), and estimated the treatment gap in Kintampo situated in the middle of Ghana.

RESULTS

249 people with ACE were identified in a study population of 113,796 individuals. After adjusting for attrition and the sensitivity of the screening method, the prevalence of ACE was 10.1/1000 (95% Confidence Interval (95% CI) 9.5-10.7). In children aged <18 years, risk factors for ACE were: family history of seizures (OR=3.31; 95% CI: 1.83-5.96), abnormal delivery (OR=2.99; 95% CI: 1.07-8.34), problems after birth (OR=3.51; 95% CI: 1.02-12.06), and exposure to Onchocerca volvulus (OR=2.32; 95% CI: 1.12-4.78). In adults, a family history of seizures (OR=1.83; 95% CI: 1.05-3.20), never attended school (OR=11.68; 95% CI: 4.80-28.40), cassava consumption (OR=3.92; 95% CI: 1.14-13.54), pork consumption (OR=1.68; 95% CI: 1.09-2.58), history of snoring at least 3 nights per week (OR=3.40: 95% CI: 1.56-7.41), exposure to Toxoplasma gondii (OR=1.99; 95% CI: 1.15-3.45) and Onchocerca volvulus (OR=2.09: 95% CI: 1.29-3.40) were significant risk factors for the development of ACE. The self-reported treatment gap was 86.9% (95% CI: 83.5%-90.3%).

CONCLUSION

ACE is common within the middle belt of Ghana and could be reduced with improved obstetric care and prevention of parasite infestations such as Onchocerca volvulus and Toxoplasma gondii.

Addressing the treatment gap and societal impact of epilepsy in Rwanda--Results of a survey conducted in 2005 and subsequent actions

This study, supported by the Rwandan Ministry of Health and the World Health Organization, was conducted in 2005 to determine the prevalence of epilepsy and its sociocultural perception in Rwanda, as well as epilepsy-related knowledge and practices of health-care professionals (HCPs). A cross-sectional, nationally representative survey was conducted throughout Rwanda by trained investigators. Participants were recruited by random cluster sampling based on the organization of administrative units in the country. Overall, 1137 individuals (62% from rural areas) were interviewed. The prevalence of epilepsy was estimated to be 49 per 1000 people or 41 per 1000 for active epilepsy. Onset of epilepsy before the age of 2years was reported in 32% of the cases. Family history of epilepsy, head trauma, and premature delivery were reported in 53%, 50%, and 68% of the cases, respectively. Most (68%) patients did not receive any medical treatment for epilepsy; 21.5% had received some form of traditional treatment. According to responses from the general population, people with epilepsy should not be entitled to schooling (according to 66%), to work (according to 72%), to the use of public places (according to 69%), or to marriage (according to 66%). Furthermore, 50% believed that epilepsy was untreatable, and 40% thought that it was transmissible. Of the 29 HCPs interviewed, the majority knew the definition of epilepsy and status epilepticus, as well as basic treatment options and side effects. However, 90% believed that treatment was only necessary in the first week after a seizure. Living with epilepsy was associated heavily with stigma, and a significant treatment gap (68%) was identified. Following this study, numerous actions have been taken by the Rwandan government, the Rwandan League Against Epilepsy, and several nongovernmental organizations to increase awareness about epilepsy and to close the treatment gap. An overview of these activities is provided.

Epidemiology, causes, and treatment of epilepsy in sub-Saharan Africa

SUMMARY

Epilepsy is a common neurological disease in tropical countries, particularly in sub-Saharan Africa. Previous work on epilepsy in sub-Saharan Africa has shown that many cases are severe, partly a result of some specific causes, that it carries a stigma, and that it is not adequately treated in many cases. Many studies on the epidemiology, aetiology, and management of epilepsy in sub-Saharan Africa have been reported in the past 10 years. The prevalence estimated from door-to-door studies is almost double that in Asia, Europe, and North America. The most commonly implicated risk factors are birth trauma, CNS infections, and traumatic brain injury. About 60% of patients with epilepsy receive no antiepileptic treatment, largely for economic and social reasons. Further epidemiological studies should be a priority to improve understanding of possible risk factors and thereby the prevention of epilepsy in Africa, and action should be taken to improve access to treatment.

The consequences of refractory epilepsy and its treatment

Seizures in some 30% to 40% of patients with epilepsy fail to respond to antiepileptic drugs or other treatments. While much has been made of the risks of new drug therapies, not enough attention has been given to the risks of uncontrolled and progressive epilepsy. This critical review summarizes known risks associated with refractory epilepsy, provides practical clinical recommendations, and indicates areas for future research. Eight international epilepsy experts from Europe, the United States, and South America met on May 4, 2013, to present, review, and discuss relevant concepts, data, and literature on the consequences of refractory epilepsy. While patients with refractory epilepsy represent the minority of the population with epilepsy, they require the overwhelming majority of time, effort, and focus from treating physicians. They also represent the greatest economic and psychosocial burdens. Diagnostic procedures and medical/surgical treatments are not without risks. Overlooked, however, is that these risks are usually smaller than the risks of long-term, uncontrolled seizures. Refractory epilepsy may be progressive, carrying risks of structural damage to the brain and nervous system, comorbidities (osteoporosis, fractures), and increased mortality (from suicide, accidents, sudden unexpected death in epilepsy, pneumonia, vascular disease), as well as psychological (depression, anxiety), educational, social (stigma, driving), and vocational consequences. Adding to this burden is neuropsychiatric impairment caused by underlying epileptogenic processes ("essential comorbidities"), which appears to be independent of the effects of ongoing seizures themselves. Tolerating persistent seizures or chronic medicinal adverse effects has risks and consequences that often outweigh risks of seemingly "more aggressive" treatments. Future research should focus not only on controlling seizures but also on preventing these consequences.

Beliefs on epilepsy in Northern Ghana

Stigma associated with any chronic disease is one of the greatest challenges to the treatment of the disease. Stigma in health is a complex concept, and it causes people with a stigmatizing disease to conceal their disorder. Epilepsy is one such condition with numerous outdated, sometimes inhumane, and sometimes absurd perceptions that tend to fuel its stigma. Health-care workers who participated in an epilepsy training program as part of a World Health Organization/Ghana Health Service collaboration were asked to compile the perceptions associated with epilepsy in their communities. The comments they gathered are presented here.

The anticonvulsant and sedative effects of Gladiolus dalenii extracts in mice

Gladiolus dalenii Van Geel is a medicinal plant commonly used in traditional medicine in Africa to treat epilepsy and many other diseases. Two in vivo mouse models (maximal electroshock and pentylenetetrazol-induced convulsions) were used to evaluate the anticonvulsant activities of the plant extracts. Diazepam-induced sleep was used for the evaluation of the sedative properties. The macerated extract of G. dalenii protected 100 and 83.3% of mice against PTZ- and MES-induced seizures, respectively. The aqueous extract of G. dalenii protected 100 and 83.3% of mice against PTZ- and MES-induced seizures, respectively. The lyophilized extract of G. dalenii also protected 100 and 83.3% of mice against PTZ- and MES-induced seizures, respectively. The coadministration of G. dalenii with diazepam resulted in an additive effect, while the coadministration of G. dalenii with flumazenil or FG7142 resulted in antagonistic effects. The macerate of G. dalenii also exerted sedative activity by reducing the latency time to sleep and increasing the total duration of sleep induced by diazepam. The sleeping time increased from 16±3min in the control group to 118±11min at a dose of 150mg/kg of G. dalenii. The effects of G. dalenii suggested the presence of anticonvulsant and sedative activities that might show efficacy against secondarily generalized tonic-clonic seizures and primary generalized seizures and insomnia in humans.