The prevalence of headache with emphasis on tension-type headache in rural Tanzania: a community-based study

Neurocysticercosis Prevalence and Characteristics in Communities of Sinda District in Zambia: A Cross-Sectional Study

BACKGROUND

This study aimed at describing the epidemiology of (neuro)cysticercosis as well as its clinical and radiological characteristics in a Taenia solium endemic district of Zambia.

METHODS

This was part of a cross-sectional community-based study conducted in Sinda district to evaluate an antibody-detecting T. solium point-of-care (TS POC) test for taeniosis and (neuro)cysticercosis. All TS POC cysticercosis positive (CC+) participants and a subset of the TS POC cysticercosis negative (CC-) received a clinical evaluation and cerebral computed tomography (CT) examination for neurocysticercosis (NCC) diagnosis and staging.

RESULTS

Of the 1249 participants with a valid TS POC test result, 177 (14%) were TS POC CC+ . Cysticercosis sero-prevalence was estimated to be 20.1% (95% confidence intervals [CI] 14.6-27.0%). In total, 233 participants received a CT examination (151 TS POC CC+ , 82 TS POC CC-). Typical NCC lesions were present in 35/151 (23%) TS POC CC+ , and in 10/82 (12%) TS POC CC- participants. NCC prevalence was 13.5% (95% CI 8.4-21.1%) in the study population and 38.0% (95% CI 5.2-87.4%) among people reporting epileptic seizures. Participants with NCC were more likely to experience epileptic seizures (OR = 3.98, 95% CI 1.34-11.78, p = 0.01) than those without NCC, although only 7/45 (16%) people with NCC ever experienced epileptic seizures. The number of lesions did not differ by TS POC CC status (median: 3 [IQR 1-6] versus 2.5 [IQR 1-5.3], p = 0.64). Eight (23%) of the 35 TS POC CC+ participants with NCC had active stage lesions; in contrast none of the TS POC CC- participants was diagnosed with active NCC.

CONCLUSION

NCC is common in communities in the Eastern province of Zambia, but a large proportion of people remain asymptomatic.

Paediatric chronic pain prevalence in low- and middle-income countries: A systematic review and meta-analysis

BACKGROUND

Chronic pain is a leading cause of morbidity in children and adolescents globally, with a significant impact on quality of life. This is the first systematic review and meta-analysis on paediatric chronic pain in low- and middle-income countries (LMICs).

METHODS

Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we searched MEDLINE (via PubMed), Embase, CINAHL, PsycINFO, Web of Science, Cochrane Database of Systematic Reviews, and the WHO Global Index Medicus for all studies published prior to January 7, 2022. Articles published in all languages that included populations age 19 years and under living in LMICs were considered. Chronic pain was defined as persistent or recurrent pain that is present for ≥3 months, per the International Classification of Diseases (ICD-11) definition. Summary data were extracted from published reports and evaluated with mixed-effects regression analysis. PROSPERO Record ID: CRD42021227967.

FINDINGS

Of the 2875 studies identified, 70 articles were reviewed, with 27 studies representing 20 LMICs eligible for analysis. The average prevalence for each pain type reported with 95% confidence interval is as follows: general/multi-site/any 20% (16-25), musculoskeletal (MSK) pain 9% (7-13), abdominal pain 7% (5-10), headache 4% (2-10), and fibromyalgia per American College of Rheumatology or Yunus and Masi criteria 3% (1-10). Overall, a pooled mean of 8% chronic pain was estimated across all studies. A significantly high level of heterogeneity was found across all studies (I2  >90%). Chronic headache (OR=1·65, 95% CI 1·39-1·96), abdominal pain (OR=1·36, 95% CI 1·22-1·51), and generalized/multi-site pain (OR=1·54, 95% CI 1·31-1·81) were significantly more prevalent in females than males.

INTERPRETATION

The characterization of paediatric chronic pain in low- and middle-income countries suffers from a paucity of data and significant heterogeneity in the assessment methods. Understanding the global burden of chronic pain in this group should be prioritized.

FUNDING

None.

Tension-type headache

Tension-type headache (TTH) is the most prevalent neurological disorder worldwide and is characterized by recurrent headaches of mild to moderate intensity, bilateral location, pressing or tightening quality, and no aggravation by routine physical activity. Diagnosis is based on headache history and the exclusion of alternative diagnoses, with clinical criteria provided by the International Classification of Headache Disorders, third edition. Although the biological underpinnings remain unresolved, it seems likely that peripheral mechanisms are responsible for the genesis of pain in TTH, whereas central sensitization may be involved in transformation from episodic to chronic TTH. Pharmacological therapy is the mainstay of clinical management and can be divided into acute and preventive treatments. Simple analgesics have evidence-based effectiveness and are widely regarded as first-line medications for the acute treatment of TTH. Preventive treatment should be considered in individuals with frequent episodic and chronic TTH, and if simple analgesics are ineffective, poorly tolerated or contraindicated. Recommended preventive treatments include amitriptyline, venlafaxine and mirtazapine, as well as some selected non-pharmacological therapies. Despite the widespread prevalence and associated disability of TTH, little progress has been made since the early 2000s owing to a lack of attention and resource allocation by scientists, funding bodies and the pharmaceutical industry.

Out-patient neurological disorders in Tanzania: Experience from a private institution in Dar es Salaam

Background and introduction

Low and middle-income countries (LMIC) have a considerable burden of neurological disorders. Available profile of neurological disorders in our environment is biased towards neurological admissions. There is a paucity of data on out-patient neurological conditions in sub-Saharan Africa.

Objective

To determine the frequency and demographic data of neurological illnesses being managed at the adult out-patient neurology clinic of the Aga Khan Hospital, Dar es Salaam (AKHD).

Materials and methods

The electronic medical records of all cases with neurological diseases who presented to the adult neurology clinic of the AKHD between January 2018, and December 2019 were retrospectively reviewed and analyzed. Neurological disorders are categorized according to the international classification of diseases version-11(ICD-11).

Results

Of the 1186 patients seen in a period of 2 years, there were 597 (50.4%) females and 588(49.6%) males, with median age (IQR) of 38 (30.0–52.0) and 42 (33.0–54.5) years respectively (p = 0.001). Headache disorders (27.0%); disorders of the nerve root, plexus or peripheral nerves (23.4%); epilepsy (9.3%), cerebrovascular disorders (8.9%); movement disorders (3.6%) and disorders of cognition (3.5%) were the primary neurological conditions encountered. Musculoskeletal disorders (7.5%) and mental/behavioral disorders (5.4%) were other conditions seen in the clinic.

Conclusion

The pattern of neurological disorders in this cohort mirrors that of high-income countries. However, the manpower to tackle these conditions pales in comparison. Increasing the neurology workforce and paying extra attention to non-communicable disorders in SSA is advocated.

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Available profile of neurological disorders in our environment is biased towards neurological admissions.

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We Profile neurological out-patient consultations in Aga Khan Hospital, Dar es Salaam.

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Headache, peripheral nerve disorders, epilepsy and stroke were leading neurological disorders encountered.

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Non-communicable neurological conditions are becoming prevalent in sub-Sahara Africa and they deserve attention.

Estimating the association between being seropositive for cysticercosis and the prevalence of epilepsy and severe chronic headaches in 60 villages of rural Burkina Faso

Background

Individuals diagnosed with neurocysticercosis often present with epilepsy and sometimes with progressively worsening severe chronic headaches (WSCH). While cross-sectional associations between seropositivity to cysticercal antigens and epilepsy have been reported, few large scale studies have been conducted in West Africa and none have measured the association between seropositivity to cysticercal antigens and headaches. This study aimed at filling these knowledge gaps by estimating the strength of the cross-sectional association between seropositivity to cysticercal antigens and the prevalence of epilepsy and WSCH in 60 villages of Burkina Faso, West Africa.

Methodology/Principal findings

Baseline data from a cluster randomized controlled trial collected from January 2011 to February 2012 in 60 villages across three provinces in Burkina Faso were used. Between 78 and 80 individuals were screened for epilepsy and WSCH in each village, and those screened positive were confirmed by a physician. Seventy-five percent of all participants were asked to provide a blood sample to test for Taenia solium cysticercus circulating antigens. Hierarchical multivariable logistic models were used to measure the association between seropositivity to cysticercal antigens and epilepsy (lifetime and active) as well as WSCH. Among 3696 individuals who provided a blood sample, 145 were found to have epilepsy only, 140 WSCH only and 19 both. There were positive associations between seropositivity to cysticercal antigens and active epilepsy (prevalence odds ratio (POR): 2.40 (95%CI: 1.15–5.00)) and WSCH (POR: 2.59 (1.34–4.99)).

Conclusions/Significance

Our study is the first to demonstrate a cross-sectional association between seropositivity to cysticercal antigens and WSCH in a large community-based study conducted in West Africa. The measured cross-sectional association had a strength similar to the ones previously observed between seropositivity to cysticercal antigens and lifetime or active epilepsy. As a result, preventing new cysticercosis cases in communities may reduce the prevalence of these two important neurological disorders.

Taenia solium is a parasite that can be transmitted between humans and pigs in areas with poor sanitation and pig management practices. When this parasite infects the human brain, it can cause epilepsy or severe headaches. Our study aimed to measure the association between being seropositive to cysticercal antigens and having epilepsy (lifetime and active) or severe headaches in 60 villages of Burkina Faso. We found that active epilepsy and severe headaches were associated with seropositivity to cysticercal antigens. These results confirm prior studies which suggested an association between being seropositive for cysticercal antigens and these two neurological symptoms. Preventing cysticercosis could reduce new cases of these two neurological symptoms from occurring.

The impact of imperfect screening tools on measuring the prevalence of epilepsy and headaches in Burkina Faso

BACKGROUND

Epilepsy and progressively worsening severe chronic headaches (WSCH) are the two most common clinical manifestations of neurocysticercosis, a form of cysticercosis. Most community-based studies in sub-Saharan Africa (SSA) use a two-step approach (questionnaire and confirmation) to estimate the prevalence of these neurological disorders and neurocysticercosis. Few validate the questionnaire in the field or account for the imperfect nature of the screening questionnaire and the fact that only those who screen positive have the opportunity to be confirmed. This study aims to obtain community-based validity estimates of a screening questionnaire, and to assess the impact of verification bias and misclassification error on prevalence estimates of epilepsy and WSCH.

METHODOLOGY/PRINCIPAL FINDINGS

Baseline screening questionnaire followed by neurological examination data from a cluster randomized controlled trial collected between February 2011 and January 2012 were used. Bayesian latent-class models were applied to obtain verification bias adjusted validity estimates for the screening questionnaire. These models were also used to compare the adjusted prevalence estimates of epilepsy and WSCH to those directly obtained from the data (i.e. unadjusted prevalence estimates). Different priors were used and their corresponding posterior inference was compared for both WSCH and epilepsy. Screening data were available for 4768 individuals. For epilepsy, posterior estimates for the sensitivity varied with the priors used but remained robust for the specificity, with the highest estimates at 66.1% (95%BCI: 56.4%;75.3%) for sensitivity and 88.9% (88.0%;89.8%) for specificity. For WSCH, the sensitivity and specificity estimates remained robust, with the highest at 59.6% (49.7%;69.1%) and 88.6% (87.6%;89.6%), respectively. The unadjusted prevalence estimates were consistently lower than the adjusted prevalence estimates for both epilepsy and WSCH.

CONCLUSIONS/SIGNIFICANCE

This study demonstrates that in some settings, the prevalence of epilepsy and WSCH can be considerably underestimated when using the two-step approach. We provide an analytic solution to obtain more valid prevalence estimates of these neurological disorders, although more community-based validity studies are needed to reduce the uncertainty of the estimates. Valid estimates of these two neurological disorders are essential to obtain accurate burden values for neglected tropical diseases such as neurocysticercosis that manifest as epilepsy or WSCH.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03095339.

Undifferentiated headache: broadening the approach to headache in children and adolescents, with supporting evidence from a nationwide school-based cross-sectional survey in Turkey

BACKGROUND

Headache is a leading disabler in adults worldwide. In children and adolescents, the same may be true but the evidence is much poorer. It is notable that published epidemiological studies of these age groups have largely ignored headaches not fulfilling any specific set of ICHD criteria, although such headaches appear to be common. A new approach to these is needed: here we introduce, and investigate, a diagnostic category termed "undifferentiated headache" (UdH), defined in young people as recurrent mild-intensity headache of < 1 h's duration.

METHODS

We conducted a nationwide cross-sectional survey in 31 schools in six regions of Turkey selected by mixed convenience-based and purposive modified cluster-sampling. A validated, standardised self-completed structured questionnaire was administered by a physician-investigator to entire classes of pupils aged 6-17 years.

RESULTS

Of the identified sample of 7889 pupils, 7088 (89.8%) participated. The 1-year prevalence of UdH was 29.2%, of migraine (definite and probable) 26.7%, and of tension-type headache (TTH) (definite and probable) 12.9%. UdH differed with respect to almost all headache features and associated symptoms from both migraine and TTH. Burden of headache and use of acute medication were lower in UdH than in migraine and TTH. Headache yesterday was less common in UdH than migraine (OR 0.32; 95% CI 0.28-0.37) and TTH (OR 0.64; 95% CI 0.56-0.77). Quality of life (QoL) was better in UdH (33.6 ± 5.2) than in migraine (30.3 ± 5.6; p < 0.001) and TTH (32.4 ± 5.3; p < 0.001), but worse than in pupils without headache (35.7 ± 4.7; p < 0.001).

CONCLUSIONS

This large nationwide study in Turkey of pupils aged 6-17 years has shown that many children and adolescents have a headache type that does not conform to existing accepted diagnostic criteria. This new diagnostic category of presumably still-evolving headache (undifferentiated headache) is common. UdH differs in almost all measurable respects from both migraine and TTH. Although characterised by mild headaches lasting < 1 h, UdH is associated with significant adverse impact on QoL. Longitudinal cohort studies are needed to evaluate the prognosis of UdH but, meanwhile, recognition of UdH and its distinction from migraine and TTH has implications for epidemiological studies, public-health policy and routine clinical practice.

The prevalence of primary headache disorders in Ethiopia

BACKGROUND

Knowledge of the epidemiology of primary headache disorders in sub-Saharan Africa (SSA) remains very limited. We performed a population-based survey in rural and urban areas of Ethiopia, using methods similar to those of an earlier study in Zambia and tested in multiple other countries by Lifting The Burden.

METHODS

In a cross-sectional survey we visited households unannounced in four regions of Ethiopia: the mostly urban populations in Addis Ababa and its environs and rural populations of selected districts in Oromia, Amhara and South Nations Nationalities and People's Regions States (SNNPRS). We used cluster-randomized sampling: within clusters we randomly selected households, and one adult member (18-65 years old) of each household. The HARDSHIP structured questionnaire, translated into the local languages, was administered face-to-face by trained interviewers. Demographic enquiry was followed by diagnostic questions based on ICHD-II criteria.

RESULTS

From 2,528 households approached, 2,385 of 2,391 eligible members (1,064 [44.7%] male, 596 [25.0%] urban) consented to interview (participating proportion 99.8%). Headache in the preceding year was reported by 1,071 participants (44.9% [95% CI: 42.4-46.3]; males 37.7%, females 49.9%), and headache yesterday by 170 (7.1% [6.2-8.2]; males 45 [4.1%], females 125 [9.2%]). Adjusted for gender, age and habitation (urban/rural), 1-year prevalence of migraine was 17.7%, of tension-type headache (TTH) 20.6%, of all headache on ≥15 days/month 3.2%, and of probable medication-overuse headache (pMOH) 0.7%. The adjusted prevalence of headache yesterday was 6.4%. Very few cases (1.6%) were unclassifiable. All headache disorders were more common in females. TTH was less common in urban areas (OR: 0.3; p < 0.0001), but pMOH was very strongly associated (OR: 6.1; p < 0.0001) with urban dwelling. Education was negatively associated with migraine (OR: 0.5-0.7; p < 0.05) but (at university level) positively with pMOH (OR: 2.9; p = 0.067). Income above ETB 500/month showed similar associations: negatively with migraine (OR: 0.8; p = 0.035), positively with pMOH (OR: 2.1; p = 0.164).

CONCLUSIONS

Findings for migraine and TTH in Ethiopia were quite similar to those from Zambia, another SSA country; pMOH was much less prevalent but, as in Zambia, essentially an urban problem. Primary headache disorders are at least as prevalent in SSA as in high-income western countries.

The burden of primary headache disorders in Zambia: national estimates from a population-based door-to-door survey

BACKGROUND

Three headache disorders - migraine, tension-type headache (TTH) and medication-overuse headache (MOH) - are major contributors to population ill-health. Policy-makers need local knowledge of these to guide priority-setting. Earlier we reported the prevalence of these disorders in Zambia; here we describe the burdens attributable to them.

METHODS

This was a cross-sectional population-based survey of adults aged 18-65 years, selected by cluster-randomized sampling in the mostly urban Lusaka Province and mostly rural Southern Province. Interviewers visiting households used a structured questionnaire. Diagnoses made algorithmically applied ICHD-II criteria. Burden enquiry focused on the previous 3 months and the day before interview. Disability was estimated by applying disability weights (DWs) from the Global Burden of Disease Survey 2010.

RESULTS

From 1,134 households, 1,085 unrelated adults (450 male, 635 female) were interviewed (refusal rate 4.3%). The gender- and habitation-adjusted 1-year prevalence of migraine was 22.9%, of TTH 22.8%, of headache on ≥15 days/month 11.5%, of probable MOH (pMOH) 7.1%. Reported mean intensity of migraine attacks was 2.7, representing severe pain. People with migraine spent 10.0% of their time in the ictal state (DW: 0.433); they were therefore 4.3% disabled overall. Disability from TTH was much lower. People with pMOH (time with headache: 37.5%; DW: 0.220) were 8.3% disabled overall. Average lost productive time in the preceding 3 months for migraine was 4.1 days from work (6.3% loss) and 4.2 days (4.7% loss) from household work. Losses for pMOH were 4.8 days (7.4% loss) from work and 4.5 days (5.0% loss) from household work. In the population aged 18-65 years (effectively the working population), estimated disability from migraine was 0.98%, with 1.4% of workdays lost, and from pMOH was 0.59%, with 0.53% of workdays lost. Headache yesterday was reported by 28.3% of participants, whose average productivity yesterday was 55.9% of expectation.

CONCLUSIONS

Zambia loses 1.93% of GDP to headache, and action is required to mitigate this loss and the associated suffering. Structured headache services with their basis in primary care are the most efficient, effective, affordable and equitable solution. They could be implemented within the existing health-care infrastructure of Zambia. These matters require urgent political attention.

The epidemiology of primary headache disorders in Zambia: a population-based door-to-door survey

Background

Little is known of the epidemiology of primary headache disorders in sub-Saharan Africa. We performed a population-based survey in Zambia using methods previously tested in multiple other countries.

Methods

This cross-sectional survey was conducted by visiting households unannounced, using cluster-randomized sampling, in the mostly urban Lusaka Province and mostly rural Southern Province. Within clusters, households were selected randomly, as was one adult member (18-65 years old) of each selected household. A structured questionnaire, translated into the local languages, was administered face-to-face by trained interviewers. Demographic enquiry was followed by diagnostic questions based on ICHD-II criteria. A random sub-sample of participants were invited for subsequent physician-interview to validate the diagnostic part of the questionnaire.

Results

Of 1,134 eligible household members contacted, 1,085 (450 male, 887 urban) consented to interview (refusal rate 4.3%). Others who had been selected but remained unavailable on three visits were not counted as refusals since their reasons were unknown, but gave rise to gender biases, being mostly male in urban areas and mostly female in rural areas. Statistical correction was applied. Adjusted for gender and habitation (urban/rural), the 1-year prevalence of any headache was 61.6%, of migraine 22.9%, of tension-type headache (TTH) 22.8%, of headache on ≥15 days/month 11.5% and of probable medication-overuse headache (pMOH) 7.1%. The adjusted point-prevalence of any headache (headache yesterday) was 19.1%. There was a small proportion (5.3%) of unclassified headache, some of which may have been secondary. The overwhelmingly strong association was between urban dwelling and pMOH (OR: 8.6; P=0.0001), with an urban prevalence of 14.5% (gender-adjusted). Validation of the questionnaire was limited by participants’ reluctance to present for physician review, substantial delays in doing so and major self-selection bias among those who did. These were unavoidable problems in resource-limited Zambia.

Conclusions

Primary headache disorders, common in high-income countries, are at least as prevalent in Zambia, a sub-Saharan African country. The selectively urban problem of pMOH seems likely to reflect ready availability of non-prescription analgesics, without easy access to professional health care for headache or any focused public-health education regarding correct usage of analgesics or the dangers of their overuse.

The PACE study: past-year prevalence of tension-type headache and its subtypes in Parma's adult general population

The mean global prevalence of tension-type headache (TTH) in adult is 42 %. To date, there have been no Italian studies on TTH prevalence in the adult general population. Therefore, we conducted a cross-sectional study, called PACE, aimed at detecting the prevalence of primary headaches in the city of Parma's adult general population. 904 subjects representative of Parma's adult general population were interviewed face to face by a physician of our Headache Centre. Crude past-year prevalence for definite TTH was 19.4 % (95 % CI 16.8-21.9; 18.4 %, 95 % CI 14.6-22.3 in men, and 20.1 %, 95 % CI 16.6-23.6 in women), namely, 9.0 % (95 % CI 7.1-10.8) for infrequent TTH, 9.8 % (95 % CI 7.9-11.8) for frequent TTH, and 0.6 % (95 % CI 0.1-1) for chronic TTH. Crude prevalence for probable TTH was 2.3 % (95 % CI 1.3-3.3; 2 %, 95 % CI 0.6-3.4 in men, and 2.6 %, 95 % CI 1.2-3.9 in women). Our results indicate a TTH prevalence (19.4 %) at the lower limit of data ranges for Western countries, and prevalence rates for infrequent forms (9 %) do not appear different from those of frequent forms (9.8 %).

Epidemiology and cultural differences in tension-type headache

Tension-type headache (TTH) is the most prevalent headache worldwide Stovner et al. (Cephalalgia 27:193-210, 2007••); Robbins and Lipton (Semin Neurol 30:107-19, 2010••); Jensen and Stovner (Lancet Neurol 7:354-361, 2008). Despite being the most prevalent primary headache type, there is still a relative lack of epidemiologic data when compared to that for migraine Robbins and Lipton (Semin Neurol 30:107-19, 2010••). Out of the available data, it is apparent that there are wide variations and differences in tension-type headache epidemiology across different cultures Stovner et al. (Cephalalgia 27:193-210, 2007••). This review will focus on reviewing and comparing the epidemiology of episodic and chronic TTH in adult populations across varying continental regions. This will include prevalence, cultural variations and differences in study methodologies, common precipitants and prognosis. Possible explanations for such widely varying prevalence rates among different cultures and regions will also be discussed.

The prevalence of neurological disorders in older people in Tanzania

OBJECTIVES

There are few data on neurological disorders prevalence from low- and middle-income countries, particularly sub-Saharan Africa (SSA) and none specific to the African elderly. We aimed to determined the prevalence of neurological disorders in those aged 70 years and over in a rural African community.

MATERIALS AND METHODS

This study was a cross-sectional two-phased community epidemiological survey set in the rural Hai district of Tanzania. Screening was performed with a validated screening questionnaire with high sensitivity and specificity. Positive responders to screening underwent full neurological history and examination to confirm or refute the presence of neurological disorders and to classify the disorder using the International Statistical Classification of Diseases and Related Health Problems 10th Revision (ICD-10).

RESULTS

Of 2232 participants, there were 384 neurological diagnoses amongst 349 people. The age-adjusted prevalence of people with neurological diagnoses was 154.1 per 1000 (95% CI 139.2-169.1). The age-adjusted prevalence per 1000 of the most common neurological disorders were tremor (48.2), headache (41.8), stroke (23.0), peripheral polyneuropathy (18.6), upper limb mononeuropathy (6.5) and parkinsonism (5.9).

CONCLUSIONS

This is the first published community-based neurological disorders prevalence study specifically in the elderly in SSA. It reveals a high prevalence of neurological morbidity and demonstrates the contribution neurological disorders make to the non-communicable disease epidemic. This is likely to increase as the population of low-income countries ages constituting a public health dilemma.

Validity of a screening instrument for neurologic disability in resource-poor African communities

BACKGROUND

There have been no recent population-based studies on all-cause adult neurological morbidity in sub-Saharan Africa. We have developed a screening survey to improve the feasibility in performing these studies.

METHODS

Our screening instrument contains both history questions and examination items. We pilot tested this instrument in the Hai District, Tanzania, and Butajira, Ethiopia using trained individuals from the local communities. To measure sensitivity, we applied the instrument blindly to 25 previously-identified subjects with Parkinson's disease, stroke or epilepsy. To measure specificity, we examined 42 randomly selected previously screened subjects. We also compared the validity of the entire instrument to the history-only section.

RESULTS

There were 669 adult subjects screened in both communities (150 screen-positives, and 519 screen-negatives). The sensitivity of the instrument was 100% (95% CI 84.2-100%) and the specificity was 82.4% (95% CI 66.1-92.0%). However, when restricting the instrument to the history-only section, the sensitivity remained unchanged, but the specificity became 91.2% (95% CI 76.3-97.7%; p=0.48).

CONCLUSIONS

We have created a valid tool to screen adults for neurologic morbidity in resource-poor communities. The use of the history-only section of the tool is adequate as a screen and will improve feasibility.

Migraine attack frequency, duration, and pain intensity: disease burden derived from a community-based survey in northern Tanzania

OBJECTIVE

One goal of the campaign "Lifting the burden: The global campaign against headache" is to highlight existing evidence about headache worldwide. In this context, the aim of our study was to report the migraine-related headache burden in northern Tanzania.

METHODS

From December 2003 until June 2004 a community-based door-to-door survey was undertaken in northern Tanzania, using multistage cluster sampling. Based on the criteria of the International Headache Society, 7412 individuals were enrolled in this survey.

RESULTS

Migraine patients' average annual attack frequency was 18.4 (n = 308, standard deviation [SD] ± 47.4) with a mean duration of 16.4 hours (SD ± 20.6). The average headache intensity per patient was 2.65 (SD ± 0.59) with a calculated loss of 6.59 (SD ± 26.7) working days per year. Extrapolation of data to the investigated population (n = 7412) resulted in annual migraine burden of 281.0 migraine days per 1000 inhabitants.

CONCLUSIONS

To our knowledge, this study reports for the first time the burden that arises from migraine headache in a rural population of sub-Sahara Africa (SSA). As the presented migraine-related burden is considerable, we hope that our data will increase the awareness among local decision makers in allocating resources for treatment and research on headache.

Tension type headache in adolescence and childhood: where are we now?

Tension type headache (TTH) is a primary headache disorder considered common in children and adolescents. It remains debatable whether TTH and migraine are separate biological entities. This review summarizes the most recent literature of TTH with regards to children and adolescents. Further studies of TTH are needed to develop a biologically based classification system that may be facilitated through understanding changes in the developing brain during childhood and adolescence.

The prevalence of headache may be related with the latitude: a possible role of Vitamin D insufficiency?

According to recent observations, there is worldwide vitamin D insufficiency (VDI) in various populations. A number of observations suggest a link between low serum levels of vitamin D and higher incidence of chronic pain. A few case reports have shown a beneficial effect of vitamin D therapy in patients with headache disorders. Serum vitamin D level shows a strong correlation with the latitude. Here, we review the literature to delineate a relation of prevalence rate of headaches with the latitude. We noted a significant relation between the prevalence of both tension-type headache and migraine with the latitude. There was a tendency for headache prevalence to increase with increasing latitude. The relation was more obvious for the lifetime prevalence for both migraine and tension-type headache. One year prevalence for migraine was also higher at higher latitude. There were limited studies on the seasonal variation of headache disorders. However, available data indicate increased frequency of headache attacks in autumn–winter and least attacks in summer. This profile of headache matches with the seasonal variations of serum vitamin D levels. The presence of vitamin D receptor, 1α-hydroxylase and vitamin D-binding protein in the hypothalamus further suggest a role of vitamin D deficiency in the generation of head pain.

Prevalence of migraine headache in a rural area of northern Tanzania: A community-based door-to-door survey

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.