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Nodding Syndrome is a poorly understood epilepsy disorder in sub-Saharan Africa. The cause(s) of the disease, risk factors and long-term outcomes are unknown or controversial. The objectives of this study were to describe the long-term clinical course and treatment outcomes of individuals suffering from Nodding Syndrome. In addition, we aimed to provide a comprehensive characterization of the epileptological and social features of patients with Nodding Syndrome. From 11/2014 to 4/2015, we conducted a hospital-based, cross-sectional and observational study in Mahenge, Tanzania. Seventy-eight individuals (female:male ratio: 40:38, age at examination: 21.1 ± 6.39 (SD) years) have been enrolled, of whom 38 (49%) had also been examined in 2005 and in 2009. The 10-year clinical course analysis of this revisited subgroup revealed a calculated case fatality of 0.8-2.3%. Progressive physical or cognitive deterioration has not been observed in any of the 78 individuals and more than half of the people studied (38/69; 55%) managed to live and work independently. 14/78 individuals (18%) were seizure-free, (no head nodding, no other seizure types), 13 of whom were taking antiseizure medication. Phenytoin was more effective against head nodding seizures (14/19 (74%)) than monotherapy with other available antiseizure medication (phenobarbitone 12/25 (48%) and carbamazepine 7/22 (32%), p = 0.02, chi-square test). Our ten-year clinical outcome data show that Nodding Syndrome is not a fatal disease, however, the response to treatment is worse than in epilepsy patients in general. Phenytoin may be more effective than carbamazepine and phenobarbitone, but further studies are needed to confirm this observation., Competing Interests: Declaration of competing interest The authors have no competing interests to declare that are relevant to the content of this article., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Previous studies have described the association of onchocerciasis (caused by Onchocerca volvulus) with epilepsy, including nodding syndrome, although a clear etiological link is still missing. Cases are found in different African countries (Tanzania, South Sudan, Uganda, Democratic Republic of the Congo, Central African Republic and Cameroon). In our study we investigated immunological parameters (cytokine, chemokine, immunoglobulin levels) in individuals from the Mahenge area, Tanzania, presenting with either epilepsy or nodding syndrome with or without O. volvulus infection and compared them to O. volvulus negative individuals from the same endemic area lacking neurological disorders. Additionally, cell differentiation was performed using blood smears and systemic levels of neurodegeneration markers, leiomodin-1 and N-acetyltyramine-O, β-glucuronide (NATOG) were determined. Our findings revealed that cytokines, most chemokines and neurodegeneration markers were comparable between both groups presenting with epilepsy or nodding syndrome. However, we observed elevated eosinophil percentages within the O. volvulus positive epilepsy/nodding syndrome patients accompanied with increased eosinophilic cationic protein (ECP) and antigen-specific IgG levels in comparison to those without an O. volvulus infection. Furthermore, highest levels of NATOG were found in O. volvulus positive nodding syndrome patients. These findings highlight that the detection of distinct biomarkers might be useful for a differential diagnosis of epilepsy and nodding syndrome in O. volvulus endemic areas. Trial-registration: NCT03653975., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Arndts et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Background: With an estimated lifetime prevalence of epilepsy of 7.6 per 1,000 people, epilepsy represents one of the most common neurological disorders worldwide, with the majority of people with epilepsy (PWE) living in low-income and middle-income countries (LMICs). Adequately treated, up to 70 % of PWE will become seizure-free, however, as many as 85% of PWE worldwide, mostly from LMICs, do not receive adequate treatment., Objective: To assess the impact of the presence of a neurologist on the management of PWE in Tanzania., Methods: Two epilepsy clinics in rural Tanzania, one continuously attended by a neurologist, and one mainly attended by nurses with training in epilepsy and supervised intermittently by specialist doctors (neurologists/psychiatrists) were comparatively analyzed by multivariable linear and logistic regression models with regard to the outcome parameters seizure frequency, the occurrence of side effects of antiepileptic medication and days lost after a seizure., Results: The presence of a neurologist significantly reduced the mean number of seizures patients experienced per month by 4.49 seizures (p < 0.01) while leading to an increase in the occurrence of reported side effects (OR: 2.15, p = 0.02)., Conclusion: The presence of a neurologist may play a substantial role in reducing the burden of the disease of PWE in LMICs. Hence, specialist training should be encouraged, and relevant context-specific infrastructure established., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Background: Neurocysticercosis (NCC), a zoonotic disease caused by the pork tapeworm T. solium, represents one of the most common causes of secondary epilepsy but remains often undiagnosed due to lack of awareness and diagnostic facilities., Methodology: We pooled data from four cross-sectional studies on epilepsy and NCC in eastern Africa. Study sites were in Uganda, Malawi and in Tanzania (Dar es Salaam and Haydom). The study in Uganda and Malawi were community-based, the two studies in Tanzania were hospital-based. The same questionnaire was used for assessment of clinical characteristics of patients with epilepsy. Computed tomography (CT) scans and serological testing were performed in order to diagnose NCC., Results: Overall, 1,179 people with epilepsy were included in our analysis. Of those, 941 PWE underwent CT scanning and were pooled for NCC analysis. Seventy patients were diagnosed with NCC, but NCC prevalence differed considerably between sites ranging from 2.0% (95%CI 0.4% to 3.6%) in Dar es Salaam to 17.5% (95%CI 12.4% to 22.6%) in Haydom. NCC prevalence did not show any association with sex but increased with age and was higher in rural than urban settings. In addition, being a farmer, non-Muslim, eating pork and living with pigs close by was associated with a higher NCC prevalence. PWE with NCC experienced their first epileptic seizure around 3 years later in life compared to PWE without NCC and their epileptic seizures seemed to be better controlled (p&lt;0.001). There was no difference between focal onset seizures and focal signs on neurological examination in both groups (p = 0.49 and p = 0.92, respectively). The rT24H-EITB had a sensitivity for the detection of NCC of 70% (95% confidence interval [CI] 51 to 84%), the LLGP of 76% (95%CI 58 to 89%) and the antigen ELISA of 36% (95% CI 20 to 55%)., Conclusions: NCC is prevalent among PWE in eastern Africa, although it may not be as common as previously stated. Demographic characteristics of PWE with NCC differed from those without NCC, but semiological characteristics and results on neurological examination did not differ compared to PWE without NCC. Interestingly, seizures seemed to be less frequent in PWE with NCC. Being aware of those differences and similarities may help triaging PWE for neuroimaging in order to establish a diagnosis of NCC., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2022 Stelzle et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Background: Epilepsy is one of the most common neurological disorders worldwide. Yet, its treatment gap is large in some areas and especially in sub-Saharan Africa data on clinical, radiological and semiological characteristics, as well as on treatment of persons with epilepsy (PWE) are still scarce., Methods: We pooled data from four cross-sectional studies on epilepsy in eastern Africa. Two studies from Malawi and Uganda were community-based; two studies in Tanzania (urban Dar es Salaam and rural Haydom) were hospital-based. Clinical characteristics of PWE were assessed by the same questionnaire. Additionally, data on treatment were collected and computed tomography (CT) scans were performed., Results: Overall, 1179 PWE were included in our analysis (581 (49.3%) female, median age 22 years (IQR 15-32 years)). Up to 25% of the patients had focal onset seizures. Those showed a higher rate of remarkable CT scan findings, with especially post-ischaemic and neurocysticercosis-associated lesions, compared to PWE with generalized onset seizures (35.1% vs. 20%). The majority of the patients experienced tonic-clonic seizures (70-85%). Only 67-78% of PWE received anti-seizure medication (ASM) treatment in the community-based studies, mostly monotherapy with phenobarbital, phenytoin or carbamazepine. Yet, underdosage was frequent and a large proportion of PWE received alternative non-ASM treatment consisting of herbal treatment (up to 83%) and/or scarification (up to 20%)., Conclusions: Epilepsy is common in sub-Saharan Africa, often caused by neurocysticercosis or ischaemic strokes. PWE suffer from high seizure rates and subsequent injuries, as well as from socio-economic consequences due to insufficient ASM treatment. This pooled analysis illustrates the need for structural programmes for adequate identification, education, assessment and treatment of PWE in sub-Saharan Africa., (© 2022. The Author(s).)

Objective: To analyse the cumulative incidence of febrile seizures, to evaluate the accuracy of our screening questionnaire and to describe clinical characteristics of children with febrile seizure in an urban population in Tanzania., Methods: A large random cluster sampled population was screened for a febrile seizure history as part of a larger epilepsy study using a standardised questionnaire in a two-stage door-to-door survey in Tanzania. A subset of screen positive participants was further examined for confirmation of diagnosis and evaluation of clinical characteristics., Results: Overall, 49 697 people were screened for a febrile seizure history of whom 184 (0.4%) screened positive. Women more commonly screened positive than men (112 [0.4%] vs. 72 [0.3%]). There was no marked difference between age groups or education. The positive predictive value of the screening tool was 37% (95% CI 24-51%) but its accuracy varied with the age of interviewed individuals. Cumulative incidence rates were estimated between 1.1% and 2.0% after adjusting for the inaccuracy of the screening tool. Most febrile seizures occurred before the age of two (65%) and most children had more than one episode (80%). A large proportion of children had complex febrile seizure (65%), often caused by malaria or respiratory infections., Conclusions: The community-based cumulative incidence of a febrile seizure history in an urban Tanzanian population was similar to rates reported from other rural populations after adjusting for the inaccuracy of our screening tool. Based on the integrated nature of the febrile seizure questionnaire, screening positivity rates may have been too low. This has implications for the design of future studies. The majority of cases had complex febrile seizures often associated with malaria. This has implications for clinical case management., (© 2021 The Authors Tropical Medicine & International Health Published by John Wiley & Sons Ltd.)

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.

Neurocysticercosis (NCC) is a major cause of epilepsy in regions where pigs are free-ranging and hygiene is poor. Pork production is expected to increase in the next decade in sub-Saharan Africa, hence NCC will likely become more prevalent. In this study, people with epilepsy (PWE, n=212) were followed up 28.6 months after diagnosis of epilepsy. CT scans were performed, and serum and cerebrospinal fluid (CSF) of selected PWE were analysed. We compared the demographic data, clinical characteristics, and associated risk factors of PWE with and without NCC. PWE with NCC (n=35) were more likely to be older at first seizure (24.3 vs. 16.3 years, p=0.097), consumed more pork (97.1% vs. 73.6%, p=0.001), and were more often a member of the Iraqw tribe (94.3% vs. 67.8%, p=0.005) than PWE without NCC (n=177). PWE and NCC who were compliant with anti-epileptic medications had a significantly higher reduction of seizures (98.6% vs. 89.2%, p=0.046). Other characteristics such as gender, seizure frequency, compliance, past medical history, close contact with pigs, use of latrines and family history of seizures did not differ significantly between the two groups. The number of NCC lesions and active NCC lesions were significantly associated with a positive antibody result. The electroimmunotransfer blot, developed by the Centers for Disease Control and Prevention, was more sensitive than a commercial western blot, especially in PWE and cerebral calcifications. This is the first study to systematically compare the clinical characteristics of PWE due to NCC or other causes and to explore the utility of two different antibody tests for diagnosis of NCC in sub-Saharan Africa.

The social stigma toward people with epilepsy (PWE) varies greatly between cultures. In this study, 167 people (59 PWE, 62 relatives, 46 villagers) in a rural area of northern Tanzania were interviewed at the hospital and in the community regarding their prevailing beliefs about epilepsy and attitudes toward PWE. Seventy-eight of those interviewed (46.7%) thought that epilepsy was due to supernatural causes, but 86 (51.5%) assumed that epilepsy is caused by brain disorders or is inherited. According to the interviewees, epilepsy impacts on the lives of affected people. 65.3% (n=109) thought that PWE should not attend school or go to work and 38.3% (n=64) were of the opinion that PWE had decreased chances of getting married. A minority (11.4%; n=19) thought that epilepsy was a reason not to have children. In summary, supernatural and more scientific ideas about the causes of epilepsy seem to coexist. Nevertheless, there is considerable stigma toward PWE, which needs to be interpreted within the sociocultural context of the study., (Copyright © 2010 Elsevier Inc. All rights reserved.)

Introduction: Several reports indicate high prevalences of both onchocerciasis and epilepsy in some regions of Africa. This raises the question of whether these diseases are associated. We therefore investigated people with epilepsy and/or onchocerciasis living in an area in Tanzania endemic for Onchocerca volvulus (O. volvulus)., Methods: We collected clinical information, skin snips, and blood from 300 individuals, and cerebrospinal fluid (CSF) from 197. Participants were allocated to 4 groups consisting of people with epilepsy and onchocerciasis (n=135), those with either epilepsy (n=61) or onchocerciasis only (n=35), and healthy individuals (n=69). Samples were evaluated for microfilaria, IgG4 antibodies against O. volvulus, O. volvulus antibody index (CSF/serum), and CSF routine parameters. Polymerase chain reaction (PCR) was performed on skin snips and CSF., Results: No difference was found in microfilarial density between participants with and without epilepsy (P=0.498). The antibody index was raised in 2 participants. CSF PCR was negative in all samples tested., Discussion: Our results do not give evidence of a relationship between O. volvulus and epilepsy. Despite the fact that 2 participants had raised antibody index, the existence of cerebral onchocerciasis caused by migration of microfilariae into the CSF appears unlikely. However, to date unexplored reactions to the infestation with O. volvulus causing epilepsy cannot be excluded.

We have previously described a seizure disorder characterized by head nodding (HN). In a prospective study in southern Tanzania, we evaluated 62 patients with HN. Here, we report the patients' clinical characteristics and those of their seizures, which indicate high seizure frequency, unsatisfactory seizure control, a high burden of cognitive impairment and disease-associated barriers to education.

Most people with epilepsy (PWE) live in developing countries with limited access to health care facilities. In sub-Saharan Africa with approximately 12 million PWE, 90% do not receive adequate medical treatment. In this context, traditional medicine, being easily accessible, plays an important role. However, in sub- Saharan Africa, studies on the attitude of people (both affected and not affected by epilepsy) towards traditional medicine for treatment of epilepsy are scarce. In this study, 167 people (59 PWE, 62 relatives, 46 villagers) were interviewed at the hospital and in the community with a semi-structured validated questionnaire regarding the prevailing attitude towards traditional medicine for treatment of epilepsy in a rural area of northern Tanzania. Various traditional healing methods (THM) could be ascertained, i.e. traditional herbal medicine, spiritual healing, scarifications and spitting. 44.3% (n=74/167) of the interviewed people were convinced that epilepsy could be treated successfully with THM. Interestingly, 34.1% (n=57/167) thought that Christian prayers could cure the cause and/or treat symptoms of epilepsy. Significantly more PWE and their relatives were in favour of THM compared to villagers not knowing about epilepsy or not being immediately affected by epilepsy (χ(2)-test, p=0.004). Further factors influencing people's attitudes towards THM were gender, tribe, religion and urbanity of people's dwellings. Our study demonstrates that not only THM but also prayers in the Christian sense seem to play an important role in people's beliefs regarding successful treatment of epilepsy. Factors influencing this belief system have been identified and are discussed.

Purpose: The main aim of this door-to-door-study was to determine the prevalence, incidence, and clinical characteristics of epilepsy in northern Tanzania., Methods: A total of 7,399 people were screened with a standardized questionnaire using "multistage random sampling.", Results: The prevalence rate of epilepsy was 11.2/1,000 [95% confidence interval (CI) 8.9-13.9/1,000] and the age-adjusted prevalence rate was 13.2/1,000. The prevalence of active epilepsy was 8.7/1,000 (95% CI 6.7-11/1,000). There was a preponderance of women. The average retrospective incidence including the last 5 years was 81.1/100,000 (95% CI 65-101/100,000). Fifty-four percent (45 of 83) of the people with epilepsy had generalized seizures without any identifiable cause; 71% (59 of 83) of the epilepsy patients had not visited health institutions prior to the study and 76% (63 of 83) had never received treatment., Discussion: Our study shows that the prevalence and incidence of epilepsy in northern Tanzania are higher compared to developed countries and that the majority of people with epilepsy do not access treatment.

Over the last decades, studies in sub-Saharan Africa have indicated that epilepsy is a highly prevalent neurological disorder. Causes may be varied with infections of the central nervous system playing an important role. Neurocysticercosis (NCC) has recently been recognised as an emerging public health problem and a growing concern throughout sub-Saharan Africa and has been estimated to be responsible for 30-50% of acquired epilepsy. NCC is closely linked with porcine cysticercosis and human taeniosis, the former reaching a prevalence of almost 50% in some pig populations. In this review, we first summarize prevalence data on epilepsy and highlight some special aspects of the disorder within sub-Saharan Africa. We then focus on the prevalence of NCC, clinical signs and symptoms and diagnostic criteria for NCC with special reference to sub-Saharan Africa. This is followed by a section on the latest developments regarding serodiagnosis of cysticercosis and a section on care management of people infected with NCC. NCC clearly represents a major risk factor of epilepsy, thus detecting and treating NCC may help cure epilepsy in millions of people in sub-Saharan Africa.

Purpose: In developing countries, neurocysticercosis (NCC) is a common cause of epilepsy. Most of the work on NCC and epilepsy has been compiled in Latin America. To date, comprehensive neuroimaging studies are missing in sub-Saharan Africa., Methods: In our study, we interviewed 212 people with epilepsy (PWE) and performed cerebral computed tomography (CT) at the Haydom Lutheran Hospital in northern Tanzania. Control cerebral CT scans were selected from 198 consecutive individuals without epilepsy. Sera of PWE with lesions indicating NCC (n = 20), PWE without NCC lesions (n = 20), and healthy individuals (n = 20), as well as cerebrospinal fluid (CSF) samples of PWE with NCC lesions (n = 11) were investigated for anticysticercal antibodies., Results: Definite NCC lesions were present in five (2.4%), lesions highly suggestive of NCC in 24 (11.3%), and lesions compatible with NCC in nine (4.2%) PWE. This compares to two (1.0%) people with definite NCC lesions, two (1.0%) with lesions highly suggestive of, and six (2.9%) with lesions compatible with NCC in the control group. NCC lesions were significantly more frequent in PWE compared to controls (p < 0.0001). CT results, and serum and CSF analysis taken together, we diagnosed 22 (10.4%) individuals with probable and 7 (3.3%) with definitive NCC in our cohort of PWE., Conclusion: For the first time in sub-Saharan Africa, we give evidence within a large-scale neuroimaging study that NCC, a so far neglected infectious disease, represents a major cause of epilepsy.

The classification of epilepsy, which represents the commonest neurological disorder throughout the developing world, has been difficult due to lack of diagnostic tools. Adapted to the circumstances of an epilepsy clinic in northern Tanzania, we grouped people with epilepsy (PWE) according to an adjusted version of the International Classification of Epileptic Seizures with the main groups being: generalized types of seizures (206 PWE) divided into those starting within (147 PWE) and those starting outside (59 PWE) a specific age range (6-25 years); and partial types of seizures (102 PWE) with subgroups of generalized seizures with diffuse brain damage (41 PWE), those with predominantly focal signs (60 PWE) and complex partial seizures (1 PWE). Clinical implications are discussed.

In developing countries, especially Latin America, neurocysticercosis (NCC) is a common cause of epilepsy. Recently, neurotoxocariasis has also been implicated in the pathogenesis of epilepsy. In sub-Saharan Africa data on parasitic disease and epilepsy are scarce. We therefore conducted a study in a rural hospital in northern Tanzania and analysed serum samples for anticysticercal and antitoxocaral antibodies for 40 people with epilepsy (PWE), 20 of whom had confirmed NCC on cranial computed tomography (CT) and 20 healthy individuals. Cerebrospinal fluid (CSF) of 11 PWE with NCC lesions on cranial CT was also investigated. Antibodies were determined using ELISA and Western blot. Six PWE with NCC lesions showed anticysticercal antibodies in serum. Of those, five had active lesions. Anticysticercal antibodies were significantly more frequent in PWE with active NCC than in those with inactive NCC (P<0.01). CSF samples were positive for anticysticercal antibodies in five patients, of whom four had active lesions on cranial CT. Antitoxocaral antibodies were detected in sera of 11 (55%) PWE with NCC lesions, of eight (40%) PWE without lesions on cranial CT and of eight (40%) controls. In our study anticysticercal antibodies in both serum and CSF were associated with active NCC in PWE, whereas there was no relationship between antitoxocaral antibodies and epilepsy.

Objective: A door-to-door survey was carried out to assess the prevalence of active epilepsy in the rural population within the catchment area of the Mnero Diocesan Hospital in Southern Tanzania., Methods: A total of 4,905 individuals living in 1,047 households were enrolled in a study, consisting of a screening dialogue with a representative family member followed by a face-to-face interview with the affected subject. The diagnosis of epilepsy followed clinical guidelines proposed by the International League Against Epilepsy (ILAE)., Results: We detected 42 cases (21 males and 21 females) of active epilepsy (8.6/1,000; 95% CI: 6.0/1,000-11.1/1,000; age-adjusted prevalence ratio: 7.4/1,000). Thirty of them met the case definitions of generalized seizures, whereas 12 patients reported partial seizures. The peak prevalence was found in both sexes in the second decade of life (f: 16.9/1,000; m: 15.8/1,000; t: 16.4/1,000), with a second peak in the group aged 30-39 years (f: 10.4/1,000; m: 8.8/1,000; t: 9.7/1,000). Eleven patients (26.2%) were classified as "strongly suspected of symptomatic" epilepsy, the remaining 31 patients (73.8%) as possibly being idiopathic, symptomatic, or cryptogenic epilepsy cases., Discussion: This study provides baseline data about the active epilepsy prevalence in a rural African population. Compared to western countries, our study confirmed a pattern toward higher prevalence of epilepsy in tropical countries. As shown in previous studies, we observed a higher prevalence of epilepsy in children and adolescents, followed by a steady decline with increasing age. Reasons for this type of frequency could be ascribed to malnutrition, trauma, genetic conditions, antenatal and prenatal care, diseases resulting in febrile convulsions, cerebral infections and may even result in death in specifically diseased individuals.

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. [ABSTRACT FROM AUTHOR]

Objectives Nodding syndrome ( NS), a new epilepsy disorder of sub-Saharan Africa, has only recently been classified. In a study conducted in southern Tanzania in 2005, 62 patients with NS were analyzed in great detail. The present study, a follow-up investigation, was conducted to evaluate the progression of NS over time and to obtain serial electroencephalography ( EEG) data. Methods Of the 62 NS patients, 53 (85.5%), the majority of whom were currently on some form of antiepileptic treatment, could be reevaluated in 2009 with a standardized questionnaire. A subset of these patients (25/53) underwent EEG investigation. Results In patients with 'head nodding ( HN) only' in 2005, 10 (43.5%) of 23 remained with the same diagnosis, whereas 5 (21.7%) of 23 had developed ' HN plus' (i.e., HN and generalized tonic-clonic seizures). Six patients (26.1%) had seizures other than HN only, and two patients (8.7%) had fully recovered. In the ' HN plus' group of 2005, 9 (30.0%) of 30 patients remained ' HN plus,' and 15 patients (50.0%) had seizures other than HN only. Four patients (13.3%) reverted to ' HN only,' and two patients (6.7%) stopped all seizures. In 11 (44.0%) of 25 patients, electroencephalography ( EEG) showed generalized slowing. Six (54.6%) of these 11 abnormal EEG studies further showed generalized epileptiform discharges: (1) ictal electroencephalographic pattern with generalized 2.5 Hz spike and waves in two patients and (2) interictal bursts of 1.5-2 Hz spike and waves in four patients. Significance This follow-up study confirms that HN represents an epilepsy disorder, possibly of the atypical absence type with dynamic development over time. [ABSTRACT FROM AUTHOR]

An epidemic illness characterized by head nodding associated with onchocerciasis has been described in eastern Africa since the early 1960s; we summarize published reports and recent studies. Onset of nodding occurs in previously healthy 5-15-year-old children and is often triggered by eating or cold temperatures and accompanied by cognitive impairment. Its incidence has increased in Uganda and South Sudan over the past 10 years. Four case-control studies identified modest and inconsistent associations. There were nonspecific lesions seen by magnetic resonance imaging, no cerebrospinal fluid inflammation, and markedly abnormal electroencephalography results. Nodding episodes are atonic seizures. Testing has failed to demonstrate associations with trypanosomiasis, cysticercosis, loiasis, lymphatic filariasis, cerebral malaria, measles, prion disease, or novel pathogens; or deficiencies of folate, cobalamin, pyridoxine, retinol, or zinc; or toxicity from mercury, copper, or homocysteine. There is a consistent enigmatic association with onchocerciasis detected by skin snip or serologic analysis. Nodding syndrome is an unexplained epidemic epilepsy. [ABSTRACT FROM AUTHOR]