Summary Purpose:  In the 1960s in Tanzania, L. Jilek‐Aall observed a seizure disorder characterized by head nodding (HN). Decades later, “nodding disease,” reminiscent of what was seen in Tanzania, was reported from Sudan. To date this seizure disorder has not been classified and possible causes still remain obscure. Methods:  In a prospective study in southern Tanzania, we evaluated 62 patients with HN. Selected patients underwent blood (n = 51) and cerebrospinal fluid (CSF) (n = 48) analyses. Others were chosen for MRI (n = 12) and EEG (n = 10). Results:  Seizure type was classified as “head nodding only” and “head nodding plus,” the latter being combined with other types of seizure (n =34). During HN, consciousness was impaired in 11 patients (17.7%) and supportive signs of epileptic seizures were described by 15 (24.2%) patients. Precipitating factors were confirmed by 11 (17.7%) patients. Fifty‐six (90.3%) patients had at least one relative with epilepsy. EEG confirmed interictal epileptic activity in two patients and unspecific changes in four patients. MRI showed hippocampus pathologies (n = 5) and gliotic changes (n = 5). Skin polymerase chain reaction (PCR) positivity for Onchocerca volvulus was significantly associated with lesions on MRI. However, PCR of the CSF was negative in all cases. Conclusions:  We present a comprehensive clinical description of the “HN syndrome,” possibly a new epilepsy disorder in sub‐Saharan Africa. MRI lesions and their association with positive skin PCR for O. volvulus despite negative PCR of the CSF is intriguing and deserves attention. Furthermore, the high prevalence of hippocampus sclerosis and familial clustering of epilepsy may point toward other potential pathogenetic mechanisms.

Background: Onchocerciasis has been implicated in the pathogenesis of epilepsy. The debate on a potential causal relationship between Onchocerca volvulus and epilepsy has taken a new direction in the light of the most recent epidemic of nodding syndrome. Objective: To document MRI changes in people with different types of epilepsy and investigate whether there is an association with O. volvulus infection. Methods: In a prospective study in southern Tanzania, an area endemic for O. volvulus with a high prevalence of epilepsy and nodding syndrome, we performed MRI on 32 people with epilepsy, 12 of which suffered from nodding syndrome. Polymerase chain reaction (PCR) of O. volvulus was performed in skin and CSF. Results: The most frequent abnormalities seen on MRI was atrophy (twelve patients (37.5%)) followed by intraparenchymal pathologies such as changes in the hippocampus (nine patients (28.1%)), gliotic lesions (six patients (18.8%)) and subcortical signal abnormalities (three patients (9.4%)). There was an overall trend towards an association of intraparenchymal cerebral pathologies and infection with O. volvulus based on skin PCR (Fisher's Exact Test p=0.067) which was most pronounced in children and adolescents with nodding syndrome compared to those with other types of epilepsy (Fisher's Exact Test, p=0.083). Contrary to skin PCR results, PCR of CSF was negative in all patients. Conclusion: The observed trend towards an association of intraparenchymal cerebral pathological results on MRI and a positive skin PCR for O. volvulus despite negative PCR of CSF is intriguing and deserves further attention.

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.

SUMMARYPurpose: 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.

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.

The aim of the study was to assess the prevalence of headache with special attention to tension-type headache (TTH) in a rural area in northern Tanzania. A door-to-door study was performed using a standardized and validated questionnaire. A total of 7412 participants were screened. The total headache prevalence during the past year was 12.1%; the overall 1-year prevalence of TTH was 7%; 5% reported episodic TTH and 0.4% chronic TTH. Borderline cases (International Headache Society code 2.3) were described in 1.6%. The prevalence of headache was highest in the 41-50-year-old group in women and in the 61+ age group in men. This is the first account of the prevalence of TTH in a rural Tanzanian population, and shows that headache in general and, more specifically, TTH are prevalent disorders that deserve attention. However, the prevalence of primary headache seems to be lower than in Western countries.

Our aim was to assess the 1-year prevalence of migraine headache in a rural population within the catchment area of the Haydom Lutheran Hospital in northern Tanzania. From December 2003 until June 2004 a community-based door-to-door survey was carried out, using a questionnaire based on the criteria of the International Headache Society, including 1192 households with 7412 individuals selected by multistage cluster-random sampling. The overall 1-year prevalence of migraine headache was found to be 4.3% [316/7412, 95% confidence interval (CI) 3.8, 4.7] with an age-adjusted rate of 6.0% and a male : female ratio of 1:2.94 (P < 0.001). Of these individuals, 132 did not fulfil all criteria for migraine headache, hence, these patients had to be classified as migrainous disorders with a crude prevalence rate of 1.8% (132/7412. 95% CI 1.5, 2.1). The remaining 184 patients met all criteria for migraine resulting in a 1-year prevalence of 2.5% (184/7412, 95% CI 2.1, 2.9) and a male : female ratio of 1:2.51 (P < 0.001). The present survey shows that migraine headache is not uncommon in northern Tanzania. The recorded prevalence of migraine headache is located within the median of previous African prevalence surveys, which confirms the trend of lower migraine frequencies in rural Africa compared with western countries.

Restless legs syndrome (RLS) is a highly prevalent movement disorder. However, prevalences seem to vary amongst different ethnicities. To date, no community-based prevalence studies on RLS have been reported from the African continent. We have conducted a community-based, door-to-door study in northern Tanzania. Over a period of 16 months, 7,654 people aged 14 years and older were screened for the RLS Essential Diagnostic Criteria. Sampling was performed according to the method of "multistage cluster sampling." People who screened positive where reinterviewed and physically examined by a specialist neurologist. During the screening phase, 10 people answered "yes" to at least one of the screening questions. After reinterviewing those people, the result was confirmed in five people only. After careful re-evaluation of the results, only one person was diagnosed with RLS. Because of methodological limitations a definite prevalence may only be calculated from larger population-based studies of different African ethnicities with screening questions adapted to the cultural context.