Parasitic, bacterial, viral, immune-mediated, metabolic and nutritional factors associated with nodding syndrome

Nodding syndrome is a neglected, disabling and potentially fatal epileptic disorder of unknown aetiology affecting thousands of individuals mostly confined to Eastern sub-Saharan Africa. Previous studies have identified multiple associations-including Onchocerca volvulus, antileiomodin-1 antibodies, vitamin B6 deficiency and measles virus infection-yet, none is proven causal. We conducted a case-control study of children with early-stage nodding syndrome (symptom onset <1 year). Cases and controls were identified through a household survey in the Greater Mundri area in South Sudan. A wide range of parasitic, bacterial, viral, immune-mediated, metabolic and nutritional risk factors was investigated using conventional and state-of-the-art untargeted assays. Associations were examined by multiple logistic regression analysis, and a hypothetical causal model was constructed using structural equation modelling. Of 607 children with nodding syndrome, 72 with early-stage disease were included as cases and matched to 65 household- and 44 community controls. Mansonella perstans infection (odds ratio 7.04, 95% confidence interval 2.28-21.7), Necator americanus infection (odds ratio 2.33, 95% confidence interval 1.02-5.3), higher antimalarial seroreactivity (odds ratio 1.75, 95% confidence interval 1.20-2.57), higher vitamin E concentration (odds ratio 1.53 per standard deviation increase, 95% confidence interval 1.07-2.19) and lower vitamin B12 concentration (odds ratio 0.56 per standard deviation increase, 95% confidence interval 0.36-0.87) were associated with higher odds of nodding syndrome. In a structural equation model, we hypothesized that Mansonella perstans infection, higher vitamin E concentration and fewer viral exposures increased the risk of nodding syndrome while lower vitamin B12 concentration, Necator americanus and malaria infections resulted from having nodding syndrome. We found no evidence that Onchocerca volvulus, antileiomodin-1 antibodies, vitamin B6 and other factors were associated with nodding syndrome. Our results argue against several previous causal hypotheses including Onchocerca volvulus. Instead, nodding syndrome may be caused by a complex interplay between multiple pathogens and nutrient levels. Further studies need to confirm these associations and determine the direction of effect.

Onchocerciasis-associated epilepsy: an update and future perspectives

Onchocerciasis-associated epilepsy (OAE) is an important neglected public health problem in areas with high ongoing onchocerciasis transmission. The risk that children in such areas develop epilepsy is related to their Onchocerca volvulus microfilarial (mf) load. Before the implementation of mass treatment with ivermectin, microfilariae were detected in cerebrospinal fluid (CSF). More recently, neither O. volvulus microfilariae nor DNA were detected in CSF or brain tissue; however, these samples were obtained years after seizure onset. It is possible that during fever-induced increased blood-brain barrier permeability, microfilariae enter the brain and, upon dying, cause an inflammatory reaction inducing seizures. Including OAE in the onchocerciasis disease burden estimation may mobilise extra resources for onchocerciasis disease elimination and treatment/care of OAE-affected persons/families.

Nodding Syndrome: Clinical Characteristics, Risks Factors, Access to Treatment, and Perceptions in the Greater Mundri Area, South Sudan

We conducted a house-to-house survey in the Mundri, Western Equatoria state of South Sudan to investigate the clinical characteristics, risk factors, access to treatment and perceptions about nodding syndrome (NS). In total, 224 NS cases with median age of seizure onset of 10 years were identified. Head nodding only was reported in 50 (22.3%) cases, and head nodding plus other types of seizures in 174 (77.7%) cases. Wasting, stunted growth, delayed sexual development and speech and behavioral abnormalities were observed in 17 (23.6%), 16 (22.2%), 9 (17.3%), 14 (19.4%) and 4 (5.6%) cases, respectively. The consumption of rat meat, but not other bushmeat was associated with an increased risk of NS (OR 9.31, 95% CI 1.27-406.51). Children with NS were more likely to have taken ivermectin in the last 5 years (OR 2.40, 95% CI 1.33-4.43). NS cases were less likely to share a bedroom with other children (OR 0.06, 95% CI 0.02-0.16) or adults (OR 0.27, 95% CI 0.13-0.56). In conclusion, rat meat consumption is an unlikely risk factor for NS, and ivermectin intake was more common among NS cases than controls. Importantly, we documented that children with NS are stigmatized because of the misconception that NS is transmitted through direct contact.

'There Were Moments We Wished She Could Just Die': The Highly Gendered Burden of Nodding Syndrome in Northern Uganda

Nodding Syndrome (NS) occurs within a wide spectrum of epilepsies seen in onchocerciasis endemic areas of sub-Saharan Africa. It has debilitating consequences on affected individuals and increases the socio-economic, physical and psychological burden on care-givers and their households, diminishing their standing within the community. Social science research on the disproportionate burden of the disease on females is limited. Based on ethnographic research over 3 years in northern Uganda, we explored the burden of being ill and care-giving for persons with NS from a gendered perspective. We found that NS-affected females were at greater risk of physical and psychological abuse, sexual violence, unwanted pregnancies, sexually transmitted infections and stigma, in a context of deteriorating socio-economic conditions. Primary care-givers of the NS-affected, mostly women, struggled to make ends meet and were subjected to stigma and abandonment. Targeted interventions, including legal protection for affected females, stigma reduction, and psycho-social and financial support are needed.

Reducing onchocerciasis-associated morbidity in onchocerciasis-endemic foci with high ongoing transmission: a focus on the children

Efforts are being directed toward the elimination of onchocerciasis transmission in endemic areas with community-directed treatment with ivermectin (CDTI) in Africa, which greatly reduces onchocerciasis-associated disease. However, onchocerciasis remains a major public health problem in areas of South Sudan, the Democratic Republic of the Congo, Cameroon, and the Central African Republic. Strengthening onchocerciasis elimination efforts in areas with a high prevalence of disease burden is crucial to decrease transmission, morbidity, and mortality. We argue that clinical trials are needed to investigate the safety and efficacy of ivermectin treatment of Onchocerca volvulus-infected pregnant women and children younger than 5 years. Crucially, 6-monthly administration of ivermectin in school-age children at risk of onchocerciasis-associated epilepsy could be achieved by supplementing annual CDTI with an extra round of ivermectin treatment during Child Health Days in schools and/or other distribution sites every year. These strategies would help achieve the elimination of onchocerciasis and its associated disease burden.

Nodding Syndrome: A Scoping Review

Nodding syndrome (NS) is a debilitating yet often neglected neurological disease affecting thousands of children in several sub-Saharan African countries. The cause of NS remains unknown, and effective treatment options are lacking. Moreover, knowledge regarding NS is scarce and is based on a limited number of publications, with no comprehensive overview published to date. Therefore, the aim of this scoping review was to summarise the current evidence and identify existing knowledge gaps in order to help clinicians, scientists, and policymakers develop guidelines for prioritising this severe condition. We searched the Medline (Ovid), Embase (Ovid), Scopus, and Global Health Library databases in accordance with the PRISMA extension for scoping review guidance and in accordance with the Joanna Briggs Institute guidelines and methodology for a scoping review, using keywords describing NS. We then extracted and presented the original data regarding the epidemiology, aetiology, pathophysiology, clinical features, diagnosis, management, and outcomes of NS, as well as community perceptions and the psychosocial and economic impact of NS. Out of 1470 identified articles, a total of 69 were included in this scoping review. Major gaps exist in understanding the aetiology and pathogenesis of NS. Future research is urgently needed not only to address these gaps, but also to study the treatment options, epidemiology, and psychosocial and economic impacts of NS. Innovative interventions and rehabilitation programmes designed to address the psychosocial and economic burdens associated with NS are also urgently needed.

Treatment of Pregnant Women with Ivermectin during Mass Drug Distribution: Time to Investigate Its Safety and Potential Benefits

To date, pregnant women are excluded from programmes delivering community-directed treatment of ivermectin (CDTI) for onchocerciasis and preventive chemotherapy of other helminthiases because of concerns over ivermectin safety during pregnancy. This systematic exclusion sustains an infection reservoir at the community level and deprives a vulnerable population from known benefits—there are indications that treating O. volvulus infected women may improve pregnancy outcomes and reduce the risk that their children develop onchocerciasis-associated morbidities. Furthermore, teratogenic effects are seen in non-clinical experiments at doses that far exceed those used in CDTI. Lastly, early, undetected and undeclared pregnancies are being systematically exposed to ivermectin in practice. Treatment of this population requires appropriate supporting evidence, for which we propose a three-pronged approach. First, to develop a roadmap defining the key steps needed to obtain regulatory clearance for the safe and effective use of ivermectin in all pregnant women who need it. Second, to conduct a randomised placebo-controlled double-blind clinical trial to evaluate the safety and benefits of ivermectin treatment in O. volvulus infected pregnant women. Such a trial should evaluate the possible effects of ivermectin in reducing adverse pregnancy outcomes and neonatal mortality, as well as in reducing the incidence of onchocerciasis-associated epilepsy. Third, to establish a pregnancy registry for women who inadvertently received ivermectin during pregnancy. This situation is not unique to ivermectin. Access to valuable therapies is often limited, delayed, or denied to pregnant women due to a lack of evidence. Concerns over protecting vulnerable people may result in harming them. We need to find acceptable ways to build robust evidence towards providing essential interventions during pregnancy.

Risk Factors for Nodding Syndrome and Other Forms of Epilepsy in Northern Uganda: A Case-Control Study

Epidemiological studies suggest a link between onchocerciasis and various forms of epilepsy, including nodding syndrome (NS). The aetiopathology of onchocerciasis associated epilepsy remains unknown. This case-control study investigated potential risk factors that may lead to NS and other forms of non-nodding epilepsy (OFE) in northern Uganda. We consecutively recruited 154 persons with NS (aged between 8 and 20 years), and age-frequency matched them with 154 with OFE and 154 healthy community controls. Participants’ socio-demography, medical, family, and migration histories were recorded. We tested participants for O. volvulus serum antibodies. The 154 controls were used for both OFE and NS separately to determine associations. We recruited 462 people with a median age of 15 years (IQR 14, 17); 260 (56.4%) were males. Independent risk factors associated with the development of NS were the presence of O. volvulus antibodies [aOR 8.79, 95% CI (4.15–18.65), p-value < 0.001] and preterm birth [aOR 2.54, 95% CI (1.02–6.33), p-value = 0.046]. Risk factors for developing OFE were the presence of O. volvulus antibodies [aOR 8.83, 95% CI (4.48–17.86), p-value < 0.001] and being born in the period before migration to IDP camps [aOR 4.28, 95% CI (1.20–15.15), p-value = 0.024]. In conclusion, O. volvulus seropositivity was a risk factor to develop NS and OFE; premature birth was a potential co-factor. Living in IDP camps was not a risk factor for developing NS or OFE.

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.

No Evidence for the Involvement of Leiomodin-1 Antibodies in the Pathogenesis of Onchocerciasis-Associated Epilepsy

Nodding syndrome has been suggested to be triggered by neurotoxic leiomodin-1 auto-antibodies cross-reacting with Onchocerca volvulus. Here, we screened serum and CSF samples of persons with nodding syndrome and other forms of onchocerciasis-associated epilepsy (OAE) and African and European controls for leiomodin-1 antibodies by a cell-based assay (CBA) and Western blot (WB). These samples were also investigated for the presence of auto-antibodies cross-reacting with rat brain tissue by immunohistochemistry (IHC). Additionally, IHC was used to detect the leiomodin-1 protein in post-mortem brain samples of persons with OAE who died. Leiomodin-1 antibodies were detected by CBA in 6/52 (12%) and by WB in 23/54 (43%) persons with OAE compared to in 14/61 (23%) (p = 0.113) and 23/54 (43%) (p = 0.479) of controls without epilepsy. Multivariable exact logistic regression did not show an association between O. volvulus infection or epilepsy status and the presence of leiomodin-1. Leiomodin-1 antibodies were not detected in 12 CSF samples from persons with OAE or in 16 CSF samples from persons with acute-onset neurological conditions, as well as not being detected in serum from European controls. Moreover, the leiomodin-1 protein was only detected in capillary walls in post-mortem brain tissues and not in brain cells. IHC on rat brain slides with serum samples from persons with OAE or controls from persons with or without O. volvulus infection revealed no specific staining pattern. In conclusion, our data do not support OAE to be an autoimmune disorder caused by leiomodin-1 antibodies.

No Evidence Known Viruses Play a Role in the Pathogenesis of Onchocerciasis-Associated Epilepsy. An Explorative Metagenomic Case-Control Study

Despite the increasing epidemiological evidence that the Onchocerca volvulus parasite is strongly associated with epilepsy in children, hence the name onchocerciasis-associated epilepsy (OAE), the pathophysiological mechanism of OAE remains to be elucidated. In June 2014, children with unprovoked convulsive epilepsy and healthy controls were enrolled in a case control study in Titule, Bas-Uélé Province in the Democratic Republic of the Congo (DRC) to identify risk factors for epilepsy. Using a subset of samples collected from individuals enrolled in this study (16 persons with OAE and 9 controls) plasma, buffy coat, and cerebrospinal fluid (CSF) were subjected to random-primed next-generation sequencing. The resulting sequences were analyzed using sensitive computational methods to identify viral DNA and RNA sequences. Anneloviridae, Flaviviridae, Hepadnaviridae (Hepatitis B virus), Herpesviridae, Papillomaviridae, Polyomaviridae (Human polyomavirus), and Virgaviridae were identified in cases and in controls. Not unexpectedly, a variety of bacteriophages were also detected in all cases and controls. However, none of the identified viral sequences were found enriched in OAE cases, which was our criteria for agents that might play a role in the etiology or pathogenesis of OAE.

Serotonin Levels in the Serum of Persons with Onchocerciasis-Associated Epilepsy: A Case-Control Study

Onchocerciasis-associated epilepsy (OAE) is a devastating childhood disorder occurring in areas with high Onchocerca volvulus transmission. Despite epidemiological evidence showing the association between O. volvulus and epilepsy, the underlying mechanism remains unknown. Since high levels of serotonin are known to induce seizures, we investigated serotonin levels in persons with OAE and controls selected from the Democratic Republic of Congo. Serum serotonin levels were determined by ELISA in 19 persons with OAE, 32 persons with epilepsy without O. volvulus infection, 18 with O. volvulus infection but without epilepsy, and 35 with neither O. volvulus infection nor epilepsy. O. volvulus infection was diagnosed by skin snip testing and/or OV16 antibody detection. Serum serotonin levels were significantly decreased in persons with OAE compared to persons with O. volvulus infection and no epilepsy. In conclusion, an increased serotonin level is unable to explain the pathogenesis of OAE. Other hypotheses to identify the causal mechanism of OAE will need to be investigated.

High Prevalence of Epilepsy in an Onchocerciasis-Endemic Area in Mvolo County, South Sudan: A Door-To-Door Survey

In June 2020, a door-to-door household survey was conducted in Mvolo County, an onchocerciasis-endemic area in South Sudan. A total of 2357 households containing 15,699 individuals agreed to participate in the study. Of these, 5046 (32.1%, 95% CI: 31.4–32.9%) had skin itching and 445 (2.8%, 95% CI: 2.6–3.1%) were blind. An epilepsy screening questionnaire identified 813 (5.1%) persons suspected of having epilepsy. Of them, 804 (98.9%) were seen by a medical doctor, and in 798 (98.1%) the diagnosis of epilepsy was confirmed. The overall epilepsy prevalence was 50.8/1000 (95% CI: 47.6–54.4/1000), while the prevalence of nodding syndrome was 22.4/1000 (95% CI: 20.1–24.9/1000). Younger age, being male, skin itching, blindness, and living in a neighbourhood or village close to the Naam River were risk factors for epilepsy. The annual incidence of epilepsy was 82.8/100,000 (95% CI: 44.1–141.6/100,000). Among children 7–9 years old without epilepsy, 34% were Ov16 seropositive, suggesting high ongoing Onchocerca volvulus transmission, but only 41.9% of them took ivermectin during the last mass distribution. In conclusion, a high prevalence and incidence of epilepsy was observed in Mvolo, South Sudan. Strengthening of the onchocerciasis elimination programme is urgently needed in order to prevent epilepsy in this region.

Neuropathological Changes in Nakalanga Syndrome-A Case Report

Nakalanga syndrome is a clinical manifestation of onchocerciasis-associated epilepsy characterized by stunting, delayed or absent secondary sexual development and skeletal deformities, and is often accompanied by epileptic seizures. The pathophysiology of Nakalanga syndrome is unknown. Here, we describe the post-mortem findings of a 17-year-old female who died with Nakalanga syndrome in northern Uganda. Macroscopic and histopathological examination of all major organs (liver, lungs, kidney and heart), including the brain and the pituitary gland, was performed. The suspected cause of death was malaria, and all major organs and pituitary gland appeared normal, except the lungs, which were edematous consistent with the malaria. Neuropathological changes include signs of neuro-inflammation (gliosis and activated microglia), which co-localized with tau-reactive neurofibrillary tangles and threads. The pathology was most abundant in the frontal cortex, thalamic and hypothalamic regions, and mesencephalon. The choroid plexus showed psammoma bodies. These findings indicate accelerated aging, probably due to repeated seizures. The neuropathological findings were similar to other persons who died with onchocerciasis-associated epilepsy. Examination of the pituitary gland did not reveal new information concerning the underlying pathophysiological mechanism of Nakalanga syndrome. Therefore, more post-mortem studies should be performed.

Putative Autoantigen Leiomodin-1 Is Expressed in the Human Brain and in the Membrane Fraction of Newly Formed Neurons

Nodding syndrome is a pediatric epilepsy disorder associated with Onchocerca volvulus infection, but the mechanism driving this relationship is unclear. One hypothesis proposes that parasite-induced immune responses cross-react with human leiomodin-1 resulting in immune-mediated central nervous system (CNS) damage. However, as leiomodin-1 expression and epitope availability in human neurons remains uncharacterized, the relevance of leiomodin-1 autoimmunity is unknown. Leiomodin-1 transcript expression was assessed in silico using publicly available ribonucleic acid (RNA) sequencing databases and in tissue by in situ hybridization and quantitative polymerase chain reaction. Abundance and subcellular localization were examined by cell fractionation and immunoblotting. Leiomodin-1 transcripts were expressed in cells of the CNS, including neurons and astrocytes. Protein was detectable from all brain regions examined as well as from representative cell lines and in vitro differentiated neurons and astrocytes. Leiomodin-1 was expressed on the membrane of newly formed neurons, but not neural progenitor cells or mature neurons. Importantly, leiomodin-1 antibodies were only toxic to cells expressing leiomodin-1 on the membrane. Our findings provide evidence that leiomodin-1 is expressed in human neurons and glia. Furthermore, we show membrane expression mediates leiomodin-1 antibody toxicity, suggesting these antibodies may play a role in pathogenesis.

The Pathogenesis of Nodding Syndrome

Nodding syndrome is a rare, enigmatic form of pediatric epilepsy that has occurred in an epidemic fashion beginning in the early 2000s in geographically distinct regions of Africa. Despite extensive investigation, the etiology of nodding syndrome remains unclear, although much progress has been made in understanding the pathogenesis of the disease, as well as in treatment and prevention. Nodding syndrome is recognized as a defined disease entity, but it is likely one manifestation along a continuum of Onchocerca volvulus-associated neurological complications. This review examines the epidemiology of nodding syndrome and its association with environmental factors. It provides a critical analysis of the data that support or contradict the leading hypotheses of the etiologies underlying the pathogenesis of the syndrome. It also highlights the important progress made in treating and preventing this devastating neurological disease and prioritizes important areas for future research.

Clinical presentation of epilepsy in six villages in an onchocerciasis endemic area in Mahenge, Tanzania

To describe the clinical manifestations of epilepsy and access to antiseizure treatment in Mahenge in Central Tanzania, an onchocerciasis endemic area with a high prevalence of epilepsy. A door-to-door epilepsy prevalence survey was conducted in four rural and two sub-urban villages. Trained community workers used five screening questions to identify persons suspected to have epilepsy. Such individuals were interviewed and examined by a neurologist or a medical doctor with additional training in epilepsy, and were tested for Onchocerca volvulus antibodies. A total of 221 out of 8,062 (2.74%) surveyed individuals were confirmed to have epilepsy. The median age at seizure onset was 12 years (interquartile range: 7-16). Seventy-nine persons with epilepsy (PWE) (36.1%) had a family member with epilepsy, which was a sibling in 52.1%. Tonic-clonic seizures (142 individuals; 64.2%) were the most common seizure type. Nodding seizures were reported in 12.7% of PWE; the majority of them living in rural villages. Persons with nodding seizures reported more frequent seizures, presented with more psychiatric symptoms, and more often had onchocerciasis antibodies than those with other seizure types. The high rate of individuals with a seizure onset at between seven and 16 years is characteristic of onchocerciasis-associated epilepsy (OAE). Of the PWE, 77.9% met the criteria for the clinical case definition of OAE. Eighty-three PWE (37.6%) were not taking any antiepileptic medication. Phenobarbital was the antiepileptic drug most commonly prescribed in 76.1% of treated PWE. The high prevalence of epilepsy in rural villages in Mahenge most likely is related to the high prevalence of OAE. To prevent children developing OAE, strengthening the onchocerciasis elimination programme in Mahenge is urgently needed. Moreover, a decentralised epilepsy treatment programme is also needed to provide uninterrupted access to affordable antiepileptic drugs for the many PWE living in rural villages in the Mahenge area.

The Role of the Maridi Dam in Causing an Onchocerciasis-Associated Epilepsy Epidemic in Maridi, South Sudan: An Epidemiological, Sociological, and Entomological Study

Background: An epilepsy prevalence of 4.4% was documented in onchocerciasis-endemic villages close to the Maridi River in South Sudan. We investigated the role of the Maridi dam in causing an onchocerciasis-associated epilepsy epidemic in these villages. Methods: Affected communities were visited in November 2019 to conduct focus group discussions with village elders and assess the OV16 seroprevalence in 3- to 9-year-old children. Entomological assessments to map blackfly breeding sites and determine biting rates around the Maridi River were conducted. Historical data regarding various activities at the Maridi dam were obtained from the administrative authorities. Results: The Maridi dam was constructed in 1954–1955. Village elders reported an increasing number of children developing epilepsy, including nodding syndrome, from the early 1990s. Kazana 2 (the village closest to the dam; epilepsy prevalence 11.9%) had the highest OV16 seroprevalence: 40.0% among children 3–6 years old and 66.7% among children 7–9 years old. The Maridi dam spillway was found to be the only Simulium damnosum breeding site along the river, with biting rates reaching 202 flies/man/h. Conclusion: Onchocerciasis transmission rates are high in Maridi. Suitable breeding conditions at the Maridi dam, coupled with suboptimal onchocerciasis control measures, have probably played a major role in causing an epilepsy (including nodding syndrome) epidemic in the Maridi area.

Nodding syndrome research, lessons learned from the NSETHIO project

BACKGROUND

Until recently, nodding syndrome (NS) was considered as a mysterious disease of unknown etiology. A link between onchocerciasis and epilepsy was suspected for a long time. However, onchocerciasis was not considered as the cause of NS because NS was believed to occur only in onchocerciasis-endemic regions in Uganda, South Sudan, and Tanzania. In October 2015, with funding from the European Research Council, the NSETHIO group launched a trans-disciplinary, multi-country research project to identify the cause of NS and to study the link between onchocerciasis and epilepsy.

METHODS

We reviewed NSETHIO activities as well as all published papers, and compared project findings with results of previous research on NS.

RESULTS

Findings from the NSETHIO project showed that NS is only one of the clinical manifestations in the wide spectrum of onchocerciasis-associated epilepsy (OAE) that could be prevented by strengthening onchocerciasis elimination programs. NSETHIO demonstrated that OAE is an important neglected public health problem in onchocerciasis-endemic areas with no or a sub-optimally functioning onchocerciasis control strategies.

CONCLUSIONS

Today there is overwhelming evidence that NS together with the Nakalanga syndrome is clinical presentations of OAE, a condition that could be prevented by strengthening onchocerciasis elimination programs. While research needs to continue to elucidate the pathophysiological mechanisms causing NS, new strategies to accelerate onchocerciasis elimination coupled with community-based surveillance and treatment programs for epilepsy are urgently needed in areas of high Onchocerca volvulus transmission.

Psychological treatments delivered by community health workers in low-resource government health systems: effectiveness of group interpersonal psychotherapy for caregivers of children affected by nodding syndrome in Uganda

BACKGROUND

Despite increasing evidence for the benefits of psychological treatments (PTs) in low- and middle-income countries, few national health systems have adopted PTs as standard care. We aimed to evaluate the effectiveness of a group interpersonal psychotherapy (IPT-G) intervention, when delivered by lay community health workers (LCHWs) in a low-resource government health system in Uganda. The intended outcome was reduction of depression among caregivers of children with nodding syndrome, a neuropsychiatric condition with high morbidity, mortality and social stigma.

METHODS

A non-randomized trial design was used. Caregivers in six villages (n = 69) received treatment as usual (TAU), according to government guidelines. Caregivers in seven villages (n = 73) received TAU as well as 12 sessions of IPT-G delivered by LCHWs. Primary outcomes were caregiver and child depression assessed at 1 and 6 months post-intervention.

RESULTS

Caregivers who received IPT-G had a significantly greater reduction in the risk of depression from baseline to 1 month [risk ratio (RR) 0.25, 95% confidence interval (CI) 0.10-0.62] and 6 months (RR 0.33, 95% CI 0.11-0.95) post-intervention compared with caregivers who received TAU. Children of caregivers who received IPT-G had significantly greater reduction in depression scores than children of TAU caregivers at 1 month (Cohen's d = 0.57, p = 0.01) and 6 months (Cohen's d = 0.54, p = 0.03). Significant effects were also observed for psychological distress, stigma and social support among caregivers.

CONCLUSION

IPT-G delivered within a low-resource health system is an effective PT for common mental health problems in caregivers of children with a severe neuropsychiatric condition and has psychological benefits for the children as well. This supports national health policy initiatives to integrate PTs into primary health care services in Uganda.

Asymptomatic malaria parasitaemia and seizure control in children with nodding syndrome; a cross-sectional study

OBJECTIVE

Plasmodium falciparum is epileptogenic and in malaria endemic areas, is a leading cause of acute seizures. In these areas, asymptomatic infections are common but considered benign and so, are not treated. The effects of such infections on seizures in patients with epilepsy is unknown. This study examined the relationship between P. falciparum infection and seizure control in children with a unique epilepsy type, the nodding syndrome.

DESIGN

This cross-sectional study was nested in an ongoing trial 'Doxycycline for the treatment of nodding syndrome (NCT02850913)'. We hypothesised that, in patients with epilepsy, infection by P. falciparum, including asymptomatic infections, increases the risk of seizures and impairs seizure control.

SETTING AND PARTICIPANTS

Participants were Ugandan children with nodding syndrome, age ≥8 years, receiving sodium valproate. All had standardised testing including documentation of the number of seizures in the past month, a rapid malaria test and if positive, the peripheral blood parasite density.

OUTCOMES

The primary outcome was the number of seizures in the past month (30 days).

RESULTS

A total of 164/240 (68%) had malaria. Asymptomatic infections (without fever) were seen in 160/240 (67%) and symptomatic infections in 4/240 (2.7%). In participants without malaria, the median (IQR) number of seizures in the past month was 2.0 (1.0-4.0) and it was 4.0 (2.0-7.5) in participants with malaria, p=0.017. The number of seizures in asymptomatic persons was 3.0 (IQR 2.0-7.3) and 6.0 (IQR 4.0-10.0) in symptomatic individuals, p=0.024. Additionally, in asymptomatic patients, a positive correlation was observed between the parasite density and number of seizures, r=0.33, p=0.002.

CONCLUSION

In patients with nodding syndrome, both asymptomatic and symptomatic malaria are associated with an increased risk of seizures and poorer seizure control. Similar effects should be examined in other epilepsy disorders. Malaria prevention should be strengthened for these patients and chemotreatment and prevention studies considered to improve seizure control.

Nodding syndrome: recent insights into etiology, pathophysiology, and treatment

Nodding syndrome is an enigmatic neuropsychiatric and epileptiform disorder associated with psychomotor, mental, and physical growth retardation. The disorder affects otherwise previously normal children aged 3-18 years, with a slight preponderance for the male child. Nodding syndrome has been described in rural regions of some low-income countries in sub-Saharan Africa including northern Uganda, South Sudan, and a mountainous region of southern Tanzania. The cause of the disorder has hitherto eluded scientists. Neuroimaging studies show involvement of the nervous system with associated severe cortical atrophy in the affected children. The affected communities have generated a number of perceived causes including some conspiracy theories related to intentional poisoning of water sources and foods, and causes related to fumes and chemicals from ammunitions used during civil wars in the affected regions. From biomedical perspectives, the treatment of the affected children is geared towards symptoms control and rehabilitation. There is evidence that seizures and behavioral problems including wandering and episodes of aggressions are controllable with anticonvulsants, especially sodium valproate and antipsychotics. No treatments have proven effective in reversing the course of the disorder, and cure remains a distant goal. Community members have used indigenous medicines, cleansing rituals, and prayer interventions, but have not perceived any reasonable improvements. A randomized controlled clinical trial is ongoing in northern Uganda to test the efficacy and effectiveness of doxycycline in the treatment of nodding syndrome. The hypothesis underlying the doxycycline trial underscores the role of antigenic mimicry: that antibodies generated against an antigen of a microorganism that resides inside the black fly-transmitted parasite, Onchocerca volvulus becomes directed against nervous tissue in the brain. This paper reviews some of the recent advances in researches on the etiologies, pathophysiology, and treatment of nodding syndrome.

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.

Ivermectin Treatment in Patients With Onchocerciasis-Associated Epilepsy: Protocol of a Randomized Clinical Trial

BACKGROUND

Many studies have reported an association between epilepsy, nodding syndrome (NS), and onchocerciasis (river blindness). A high prevalence of epilepsy has been noted particularly in onchocerciasis hyperendemic areas where onchocerciasis is not or insufficiently controlled with mass ivermectin distribution. There is evidence that increasing the coverage of ivermectin reduces the incidence of epilepsy, and anecdotal evidence suggests a reduction in seizure frequency in onchocerciasis-associated epilepsy (OAE) patients who receive ivermectin. Finding an alternative treatment for epilepsy in these patients will have major consequences.

OBJECTIVE

The goal of the study is to assess whether ivermectin treatment decreases the frequency of seizures and leads to seizure freedom in OAE patients, including patients with NS. If we are able to demonstrate such an effect, this would strengthen the argument that onchocerciasis is causing epilepsy and therefore we should increase our efforts to eliminate onchocerciasis.

METHODS

We will conduct a randomized clinical trial in the Democratic Republic of Congo to compare seizure freedom in onchocerciasis-infested epilepsy patients who receive immediate ivermectin treatment with delayed (after 4 months) ivermectin treatment. All participants will simultaneously receive antiepilepsy drugs (AEDs) according to local guidelines for epilepsy treatment. The primary endpoint is seizure freedom defined as no seizures during the 4 month of follow-up. Secondary endpoint is significant (>50%) seizure reduction compared to baseline seizure frequency. Reduction of seizures will be compared between ivermectin and nonivermectin arms.

RESULTS

Start of enrollment is planned for August 2017, and we expect to have enrolled all 110 participants by December 2017. Results are expected in June 2018.

CONCLUSIONS

If ivermectin treatment in addition to AEDs is able to lead to seizure freedom or significantly reduces seizure frequency in OAE patients, this will have major consequences for epilepsy treatment in onchocerciasis-endemic regions. Ivermectin is donated for free and in non Loa-Loa-endemic regions has negligible side effects. Reducing the burden of epilepsy will have a major impact on quality of life and socioeconomic status of families with affected members in Africa.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03052998; https://clinicaltrials.gov/ct2/show/NCT03052998 (Archived by WebCite at http://www.webcitation.org/6roFVQSG0).

The enigmatic nodding syndrome outbreak in northern Uganda: an analysis of the disease burden and national response strategies

To date, the cause of nodding syndrome (NS) remains unknown; however, efforts continue to establish risk factors and optimal symptomatic treatments. We documented the burden and national response strategies including involvement of key stakeholders in the management of the NS epidemic in order to inform future interventions against epidemics of undetermined aetiology. Data were collected through semi-structured interviews with selected leaders in the affected districts and at the Ministry of Health, and through review of documents. We participated in and analysed the proceedings of the first international scientific conference on NS held in Kampala in August 2012. We then analysed the chronology of the NS notification and the steps undertaken in the response plan. Over 3000 children have been affected by NS in northern Uganda; with an estimated case fatality of 6.7%. The first cases of NS were reported in 1997 in internally displaced people's camps in Kitgum district; however, response efforts by the Ministry of Health and partners towards understanding the disorder and establish management only commenced in 2009. Key strategies in response to the NS epidemic have included formation of a national and district task forces, development of training manual on NS and training of primary healthcare professionals on case diagnosis and clinical management, establishment of treatment and rehabilitation centres, surveillance and promotion of researches to further inform management of the syndrome.

Nodding syndrome since 2012: recent progress, challenges and recommendations for future research

We aim to review the current epidemiology of nodding syndrome (NS) and discuss relevant gaps in research. NS and convulsive epilepsy of unknown aetiology are clustered within the same villages and families in onchocerciasis-endemic areas. They are therefore potentially different clinical expressions of the same disease. It has been difficult to perform full autopsies on NS patients who die in remote villages. Adequate fixation of tissue immediately after death is critical for the examination of brain tissue. Therefore, post-mortem transsphenoidal brain biopsies, performed immediately after death by trained nurses, will provide the best option for obtaining tissue for analysis. We suspect that certain blackflies in onchocerciasis-endemic areas may transmit a novel pathogen that could cause NS and epilepsy. This is supported by a recent drop in the number of new NS cases coinciding with vector control activities aimed at reducing blackfly populations in northern Uganda. We propose that metagenomic studies of human samples, blackflies and microfilariae are conducted to screen for pathogens, and that a clinical trial is planned to evaluate the impact of larviciding against NS and epilepsy epidemics.

'You sit in fear': understanding perceptions of nodding syndrome in post-conflict northern Uganda

Background

Nodding syndrome, a disabling epidemic epileptic encephalopathy, has affected an estimated 1,834 children in northern Uganda, with reports of as many as 3,000. Etiology is unknown and children are being treated symptomatically but inconsistently with anti-epileptic drugs.

Design

This qualitative study comprised 10 semi-structured interviews with caregivers of affected children and five focus group discussions with 23 participants; relatives, teachers, and religious leaders. Data collection and participant observation were carried out from July to September 2012 in Kitgum and Pader districts. The material was coded through inductive thematic analysis.

Results

Nodding syndrome has brought signs of discrimination in school admission procedures, founded in a fear of transmission. The suffering and loss caused by nodding syndrome is collective, and participants felt that nodding syndrome was viewed as a threat to the Acholi only, and that interventions had therefore been delayed. Multiple theories of causation exist, most commonly that the disease is caused by chemicals from bombs or that food aid distributed in IDP camps had expired or been poisoned.

A feeling of uncertainty was present in all focus group discussions, fueled by the fact that results of investigations were not being shared with the communities. It was especially agonizing that CDC results had been given to the Ugandan government in 2010 but not to the public. The definitive fear is that the disease will be the end of the Acholi.

Conclusions

This study provided insight into the perceptions of communities affected by an unknown emerging disease. Families of affected children are grieving not only their child's illness; it is a loss of social value and of lineage. The loss and suffering involved with nodding syndrome should be seen in the context of the wider suffering of a society disrupted by violent conflict. The memory of war is omnipresent and is also how nodding syndrome is understood.

Nodding syndrome in Tanzania may not be associated with circulating anti-NMDA-and anti-VGKC receptor antibodies or decreased pyridoxal phosphate serum levels-a pilot study

BACKGROUND

Nodding syndrome (NS) is a seemingly progressive epilepsy disorder of unknown underlying cause. We investigated association of pyridoxal-phosphate serum levels and occurrence of anti-neuronal antibodies against N-methyl-D-aspartate (NMDA) receptor and voltage gated potassium channel (VGKC) complex in NS patients.

METHODS

Sera of a Tanzanian cohort of epilepsy and NS patients and community controls were tested for the presence of anti-NMDA-receptor and anti-VGKC complex antibodies by indirect immunofluorescence assay. Furthermore pyridoxal-phosphate levels were measured.

RESULTS

Auto-antibodies against NMDA receptor or VGKC (LG1 or Caspr2) complex were not detected in sera of patients suffering from NS (n=6), NS plus other seizure types (n=16), primary generalized epilepsy (n=1) and community controls without epilepsy (n=7). Median Pyridoxal-phosphate levels in patients with NS compared to patients with primary generalized seizures and community controls were not significantly different. However, these median pyridoxal-phosphate levels are significantly lower compared to the range considered normal in Europeans.

CONCLUSIONS

In this pilot study NS was not associated with serum anti-NMDA receptor or anti-VGKC complex antibodies and no association to pyridoxal-phosphate serum levels was found.

Stereotypes on Nodding syndrome: responses of health workers in the affected region of northern Uganda

BACKGROUND

Nodding Syndrome is a debilitating disorder of yet unknown etiology that has affected children and adolescents aged 3 - 18 years in parts of sub Saharan African countries including Uganda, South Sudan, Tanzania and Liberia.

OBJECTIVE

To identify stereotypes and negative attitudes held by primary care health workers about nodding syndrome.

METHOD

Of one hundred health workers invited by the Uganda Ministry of Health for training on nodding syndrome from the three most affected districts of Pader, Lamwo and Kitgum forty were interviewed using a predesigned tool. Content and thematic analysis was applied.

RESULTS

There were 22 females. The median age was 33 years (range 23-54 years). The participants included Psychiatric Clinical Officers, Medical Clinical Officers, Laboratory Technicians, Midwives, Registered and Enrolled Nurses. Overall, four broad categories of negative stereotypes were identified; Nodding syndrome is 1) an incurable disease, 2) is associated with evil spirits and curses, 3) is disabling, making the patient a burden to society and 4) is a fatal illness.

CONCLUSION

Primary health care workers who lead the care of patients with nodding syndrome have several negative stereotypes that may potentially impact negatively on the quality of care they provide.