The Burden of Movement Disorders in Cameroon: A Rural and Urban‐Based Inpatient/Outpatient Study

Abstract

Background

Because of rapid demographic changes, the prevalence of movement disorders (MDs) is expected to increase in Africa. The objective of this study was to estimate the prevalence of MDs in an inpatient/outpatient‐based study of rural and urban health care centers in Cameroon.

Methods

In this retrospective medical chart review, the inpatient/outpatients settings covered an urban population (3,000,000) and a rural population (380,276). Neurological diseases were classified according to the International Statistical Classification of Diseases‐Related Health Problems, 10th revision (ICD‐10). Crude prevalence was calculated per 100 with 95% confidence intervals (CIs).

Results

Of 20,131 medical charts reviewed (13% from the rural area), 4187 patients (20.8%) with neurological complaints were identified. MDs were diagnosed exclusively from urban centers in 134 patients (3.2%): the mean patient age was 48.6 ± 18.6 years, and 54.7% were women. The most prevalent MDs were hyperkinetic movements (tremor, myoclonus, and drug‐induced MDs [ICD‐10 code G25]; prevalence, 1.19%; 95% CI, 1.192–1.194%), Parkinson's disease (ICD‐10 code G20; prevalence, 0.78%; 95% CI, 0.785–0.787%), dystonia (ICD‐10 code G24; prevalence, 0.61%; 95% CI, 0.612–0.613%), secondary parkinsonism (ICD‐10 code G21; prevalence, 0.56%; 95% CI, 0.564–0.565%), Huntington's disease (ICD‐10 code G10; prevalence, 0.09%; 95% CI, 0.091–0.092%), and ataxia (ICD‐10 code R29; prevalence, 0.04%; 95% CI, 0.0451–0.0456).

Conclusion

Although the burden of MDs is expected to increase, MDs are likely underdiagnosed in rural areas. High‐quality movement disorder training is essential to tackle this need.

Despite the high prevalence and disease burden of neurological disorders,1 most sub‐Saharan countries have less than 1 neurologist per 1 million people and lack medically trained personnel. In both high‐income and low‐income World Health Organization regions, neuropsychiatric conditions are the most important causes of disability, accounting for more than 37% of the years of healthy life lost as a result of disability.2 Population aging and changes in the distribution of risk factors have accelerated the epidemic of noncommunicable disease in many developing countries.1, 2 As a result, the burden of age‐related conditions, such as neurodegenerative diseases, is expected to increase.3 In fact, using Parkinson's disease (PD) and essential tremor (ET) as examples, the prevalence of the above‐mentioned movement disorders (MDs) will increase by 184% and 178%, respectively, by 2025 if the population structure follows current projections and the incidence rates remain stable.4

Population‐based epidemiological surveys are difficult to perform in Africa due to limitations in infrastructure and resources. Neurodegenerative diseases are certainly unrecognized in the elderly, probably because more attention is classically paid to infectious diseases.5, 6 However, the prevalence of MDs in sub‐Saharan countries is still a matter of debate, especially in rural areas. To date, few neuroepidemiological studies have been conducted in Africa showing lower prevalence estimates of MDs compared with the Western world.7, 8 In this regard, different methodologies and racial and geographic variations may contribute to these differences.9, 10 There is increasing evidence that, because of rapid demographic changes, the prevalence of MDs will be increasing in sub‐Saharan countries.11 Therefore, the main aim of this study was to estimate the prevalence of MDs in an inpatient/outpatient clinical sample from urban and rural health care centers in Cameroon, Africa.

Patients and Methods

Design

Patients with MD were identified from a registry of neurological disorders, including neurodevelopmental disorders, stroke, epilepsy, neurodegenerative diseases, MDs, neuromuscular diseases, and central nervous system (CNS) infections, from May 1, 2012 to May 1, 2014, in outpatient and inpatient settings from 2 urban public hospitals in Douala (Hospital Laquintinie and General Hospital) and 2 rural health care centers (Tiko and Mbouda) in Cameroon.

Start‐up and Ethics

The principal investigators (E.C. and K.K.) travelled to Laquintinie Hospital (Douala, Cameroon) in 2014 to invite physicians to participate in the registry of neurological diseases. During a 1‐day course, the basis of the neurological diseases registry, project methodology, and local networks between neurologists and primary care physicians were discussed. A local neurologist (J.D.) was designated as the principal co‐investigator in Cameroon. This project was approved by the Internal Review Board at Hospital Laquintinie in Douala (Cameroon) and by the principal investigator's Internal Review Board (Hospital Universitario Burgos, Burgos, Spain).

Procedure

A retrospective chart review of patients in the above‐described registry was conducted. The inpatient/outpatient settings covered an urban population of 3,000,000 inhabitants with 6 neurologists working in these facilities, and a rural population of 380,276 inhabitants with 20 physicians, mainly primary care doctors. A senior medical student from Douala University Medical School was engaged for this project (T.N.). Regular teleconferences between the investigators were conducted to discuss data collection and to analyze issues.

Outcomes

Neurological diagnoses obtained from medical charts were made by 6 neurologists for the majority of patients in the urban area and, for some patients, by internists, general practitioners, and other medical specialties (rural area). The availability of laboratory and radiological amenities that could aid the diagnosis was recorded. Neurological complaints and neurological disorders were coded according to the International Statistical Classification of Diseases‐Related Health Problems, 10th revision (ICD‐10).12 For MDs, PD was coded as G20, secondary parkinsonism was coded as G21, dystonia was coded as G24, Huntington's disease (HD) was coded as G10, ataxia was coded as R29, and hyperkinetic movements like tremor, myoclonus, and drug‐induced MDs, were coded as G25. The following data were collected from the patients' records: age, sex, profession, residence (rural vs. urban), the main neurological complaint for the first consultation, medical history (tobacco and alcohol exposure, presence of arterial hypertension, diabetes mellitus, dyslipidemia, human immunodeficiency virus infection, and malaria), district population, number of neurologists, access to laboratory, microbiological testing, and computerized tomography scan, disability (ranging from independence to some/full dependence, based on the medical chart notes and investigator criteria), and death.

Internal Validity of Neurological Diagnosis

Training for data accuracy was established using the neurological diagnosis given by the local neurologist (J.D.) based on the clinical information obtained from 11 medical charts as the gold standard and comparing this with the neurological diagnosis given by the data collector (T.N.). To certify the data collector, an inter‐rater agreement with a κ coefficient ≥0.8 was necessary. The inter‐rater agreement was low in the first round (κ coefficient = 0.5) and adequate in the second round (κ coefficient = 0.9) using 11 different medical charts.

Nonneurologist physicians involved in the care of the included patients were invited to participate for data source quality. Only 3 internists from the urban medical centers and 4 primary care physicians from the rural medical centers completed the data source quality questionnaire. These physicians provided neurological diagnoses for 10 clinical general neurology vignettes, obtaining a mean number of 8.6 ± 0.5 correct answers (urban centers) and 7.4 ± 0.8 correct answers (rural centers).

Statistical Analysis

Statistical analyses were performed using SPSS version 21.0 (SPSS, Inc., Chicago, IL). Descriptive statistics (i.e. means ± standard deviations, ranges, and 95% confidence intervals [CIs]) based on the Poisson distribution, were used to describe the demographic and clinical data. The crude prevalence rates of MDs were estimated as the number of cases per 100 individuals per age group/sex. Because of the lack of accurate information regarding the age distribution in Cameroon, adjusted age prevalence was not calculated.

Results

Of 20,131 medical charts (13% from the rural area) available from May 1, 2012 to May 1, 2014, 4187 patients (20.8%) who had neurological complaints as the main reason for admission/clinical visit were identified, including 3955 (94.5%) from the urban area and 231 (5.5%) from the rural area (area was unknown in 1 patient). Our sample included 2225 (53.5%) inpatients (90.1% urban centers, 9.9% rural centers), and 1962 (46.5%) outpatients (100% urban centers). The most frequent diseases resulting in neurological admission in this sample were cerebrovascular disease (51.05% of the sample), CNS infections (24.26%), epilepsy (10.02%), mono‐poly‐neuropathy (4.4%), CNS tumor (3.91%), headache (2.11%), and dementia (1.75%). In the rural sample, the most frequent diagnoses were cerebrovascular disease (39.1%), CNS infections (32.0%), epilepsy (7.9%), and headache (2.2%).

Information on the MDs was available from 4159 patients (99.3%). MDs were present in 134 patients (3.2% of neurological cases), with a mean age 48.6 ± 18.6 years (54.7% female). In more than 66% of the patients, those who had MDs were diagnosed in an outpatient setting. None had MDs reported in the rural area. Information regarding MDs, disability, and mortality was available in less than 40% of the patients and it is not presented. Sociodemographic characteristics are shown in Table 1.

Table 1.

Sociodemographic characteristics

Sample (n)	No. (%)
	HD, N = 2	PD, N = 46	S Park, N = 27	Tremor & Myo & DI MDs, N = 41	Dystonia, N = 18	Ataxia, N = 3	Total, N = 4187
Age: mean ± SD, y	45.0 ± 36.7	62.2 ± 12.9	60.8 ± 20.2	54.0 ± 17.0	35.5 ± 16.9	54.0 ± 17.0	48.6 ± 16.6
Males	1 (50)	30 (65.2)	16 (59.3)	19 (46.3)	6 (33.3)	1 (33.3)	1891 (45.2)
Education: illiterate‐low	1 (50)	24 (52.2)	13 (56.5)	10 (24.4)	10 (66.7)	1 (33.3)	1741 (41.6)
Working status: employee	0 (100)	17 (37.8)	8 (32.0)	14 (34.1)	3 (16.7)	1 (33.3)	1849 (44.2)
Distance to HCF: median [IQR], km	6.5 [5; 6.5]	8.5 [5; 18.5]	12.0 [5.7; 20.5]	10.0 [5.7; 22.2]	10.0 [6.5; 14.5]	0.0 [6; 10]	10.0 [6; 18]
Living status: with family	2 (100)	45 (97.8)	27 (100)	41 (100)	18 (100)	3 (100)	4173 (99.7)

HD, Huntington's disease; PD, Parkinson's disease; S Park, secondary parkinsonism; Tremor & Myo & DI MDs, tremor and myoclonus and drug‐induced movement disorders; SD, standard deviation; HCF, health care facility; IQR, interquartile range.

Health care‐based prevalence of MDs is detailed in Tables 2 and 3. Overall, in the group of older patients (aged ≥50 years old), PD and secondary parkinsonism represented 2.1% of the neurological consultations; and, for younger patients (aged <50 years), hyperkinetic movements (tremor, myoclonus, drug‐induced MDs, and dystonia) represented 1.9% the neurological consultations. The most frequent neurological complaints for PD and secondary parkinsonism were the presence of hyperkinetic movements (ICD‐10 code R25) and gait disorder (R26) in 67.3% and 84.7%, respectively, paresis (R82, R83) in 8.6% and 14.8%, respectively; mental status change (R40) and speech problems (R47) in 8.6% and 14.8%, respectively. For dystonia the most frequent complaints were pain (G54), headache (R51) in 38.8% and mental status change (R40) in 0.5%. For ataxia, the most frequent complaints were hyperkinetic movements (R25) and gait disorder (R26) in 66.6%, and for HD, no medical complaints were identified.

Table 2.

Health care setting‐based prevalence of Huntington's disease, Ataxia and Dystonia

Age, y	Huntington's disease			Ataxia			Dystonia
	Males	Females	Total	Males	Females	Total	Males	Females	Total
0–9
C/S	0/36	0/35	0/71	0/36	0/35	0/71	0/36	0/35	0/71
F (%)	0	0	0	0	0	0	0	0	0
10–19
C/S	1/81	0/134	1/215	0/81	0/134	0/215	3/81	1/134	4/215
F (%)	1.23	0	0.46	0	0	0	3.70	0.74	1.23
20–29
C/S	0/160	0/242	0/402	0/160	0/242	0/402	0/160	3/242	3/402
F (%)	0	0	0	0	0	0	0	1.23	0.74
30–39
C/S	0/246	0/378	0/624	0/246	1/378	1/624	3/246	3/378	6/624
F (%)	0	0	0	0	0.26	0.16	1.21	0.79	0.96
40–49
C/S	0/341	0/407	0/748	0/341	0/407	0/748	0/341	1/407	1/748
F (%)	0	0	0	0	0	0	0	0.24	0.13
50–59
C/S	0/422	0/473	0/895	0/422	1/473	1/895	0/422	1/473	1/895
F (%)	0	0	0	0	0	0.11	0	0.21	0.11
60–69
C/S	0/341	0/245	0/586	0/341	0/245	0/586	0/341	2/245	2/586
F (%)	0	0	0	0	0	0	0	0.81	0.34
70–79
C/S	0/180	1/248	1/428	1/180	0/248	1/428	0/180	1/248	1/428
F (%)	0	0.40	0.23	0.55	0	0.23	0	0.40	0.23
80–89
C/S	0/63	0/105	0/168	0/63	0/105	0/168	0/63	0/105	0/168
F (%)	0	0	0	0	0	0	0	0	0
≥90
C/S	0/12	0/10	0/22	0/12	0/10	0/22	0/12	0/10	0/22
F (%)	0	0	0	0	0	0	0	0	0
Total
C/S	1/1882	1/2277	2/4159	1/1882	2/2277	3/4159	6/1882	12/2277	18/4159
Prev (%)a	0.05*	0.04**	0.10***	0.05*	0.09**	0.05***	0.32*	0.53**	0.61***

C/S, cases/sample; F, frequency; Prev, prevalence.

^aConfidence intervals: Huntington's disease: *0.002–0.344, **0.002–0.284, ***0.091–0.092; ataxia: *0.002–0.344, **0.015–0.353, ***0.0451–0.0456; dystonia: *0.129–0.730, **0.285–0.946, ***0.612–0.613.

Table 3.

Health care setting‐based prevalence of Parkinson's disease, Secondary Parkinsonism and Tremor & Myoclonus and Drug Induced Movements

Age, y	Parkinson's disease			Secondary parkinsonism			Tremor & Myo & DI MDs
	Males	Females	Total	Males	Females	Total	Males	Females	Total
0–9
C/S	0/36	0/35	0/71	0/36	0/35	0/71	0/36	1/35	1/71
F (%)	0	0	0	0	0	0	0	2.85	0
10–19
C/S	1/81	0/134	1/215	1/81	0/134	1/215	2/81	3/134	5/215
F (%)	1.23	0	0.46	1.23	0	1.23	2.46	2.23	2.32
20–29
C/S	0/160	0/242	0/402	2/160	0/242	2/402	4/160	3/242	7/402
F (%)	0	0	0	1.25	0	0.49	2.50	1.23	1.74
30–39
C/S	2/246	0/378	2/624	1/246	2/378	3/624	1/246	3/378	4/624
F (%)	0.81	0	0.32	0.40	0.52	0.48	0.40	0.79	0.48
40–49
C/S	0/341	1/407	1/748	0/341	0/407	0/748	0/341	1/407	1/748
F (%)	0	0.24	0.13	0	0	0	0	0.24	0.13
50–59
C/S	8/422	5/473	13/895	1/422	3/473	4/895	4/422	4/473	8/895
F (%)	1.89	1.05	1.45	0.23	0.63	0.44	0.94	0.84	0.89
60–69
C/S	8/341	5/245	13/586	3/341	3/245	6/586	4/341	7/245	11/586
F (%)	2.34	2.04	2.21	0.87	1.22	1.02	1.17	2.85	1.87
70–79
C/S	8/180	5/248	13/428	4/180	2/248	6/428	4/180	3/248	7/428
F (%)	4.44	2.01	3.03	2.22	0.80	1.40	2.22	1.20	1.63
80–89
C/S	3/63	0/105	3/168	4/63	1/105	4/168	0/63	0/105	0/168
F (%)	4.76	0	1.78	6.34	0.95	2.38	0	0	0
≥90
C/S	0/12	0/10	0/22	0/12	0/10	0/22	0/12	0/10	0/22
F (%)	0	0	0	0	0	0	0	0	0
Total
C/S	30/1882	16/2277	46/4159	16/1882	11/2277	27/4159	19/1882	22/2277	41/4159
Prev (%)a	1.59*	0.70**	0.79***	0.85*	0.48**	0.56***	1.01*	0.97**	1.19***

C/S, cases/sample; F, frequency; Prev, prevalence; Tremor & Myo & DI MDs, tremor, myoclonus, and drug‐induced movement disorders.

^aConfidence intervals: Parkinson's disease: *1.096–2.297, **0.416–1.165, ***0.785–0.787; secondary parkinsonism: *0.503–1.409, **0.254–0.891, ***0.564–0.565); tremor, myoclonus, and drug‐induced movement disorders: *0.626–1.603, **0.621–1.484, ***1.192–1.194.

Discussion

In our study, hyperkinetic movements (tremor, myoclonus, and drug‐induced MDs; ICD‐10 code G25) were the most prevalent MDs, followed by PD (G20), dystonia (G24), secondary parkinsonism (G21), HD (G10), and ataxia (R29). Patients with MDs were diagnosed exclusively in urban health care facilities, suggesting that MDs were likely underdiagnosed and thus untreated in the rural area.

Overall, the body of literature on neurodegenerative disorders in sub‐Saharan countries is large with regard to dementia and human immunodeficiency virus‐related neurocognitive disorders, but it is limited data for other neurodegenerative disorders.3 However, based on recent estimates, it is predicted that, by 2050, there will be 139 million individuals aged 60 years and older living in sub‐Saharan Africa,4, 13 with a subsequent increase in the prevalence and burden of neurodegenerative disorders, including MDs.4 Our results are in agreement with previous studies conducted in Africa. In a rural area in Tanzania,7, 8, 14 the age‐adjusted prevalence of the most common neurological disorders in older individuals were tremor (4.8%), headache (4.1%), stroke (2.3%), and polyneuropathy (1.8%). Kuate et al.6 also reported that the most frequent complaints and neurological diseases were low back pain (19.7%), tremor and MDs (13.8%), and gait disorders (4.3%) in a hospital‐based sample in Yaoundé‐Cameroon.

The main limitation of our study is the interpretation of our prevalence estimates, because since a selected inpatient/outpatient‐based study cannot be directly compared with population‐based studies. Likewise, the prevalence estimates obtained from inpatient/outpatient settings can be limited by several factors, including patient access, type of health care facilities, and physician expertise in MDs, restricting the extrapolation of our prevalence estimates to the community or the whole country. Furthermore, although the accuracy of our data source was established by assessing general neurology knowledge in a limited number of physicians, we do not have data in terms of their specific expertise in MDs. Moreover, selection bias due to small representation of the rural population cannot be excluded.

However, despite all of these limitations, due to lack of epidemiological data about MDs in sub‐Saharan countries, this type of publication raises awareness about MDs as under‐recognized health conditions. The information is still valuable, given that the overwhelming majority of patients were diagnosed by a neurologist and there was significant interrater agreement between the local neurologist and the data collector. It is also important to note that our registry included an urban sample and a rural sample, which have been infrequently included in previous studies.5, 6 Accurate prevalence estimates of MDs are needed to address the effects of the demographic shift that is taking place in many regions of the word, including sub‐Saharan countries. On the other hand, the management of patients suffering from MDs is challenging in a population that has low access to care. There is no doubt that improving access to patients with MDs must be coupled with increased education to raise awareness of these diseases, including diagnosis and treatments. Because MDs are likely underdiagnosed in the rural areas, high‐quality movement disorder training is essential to tackle this increasing need.

Author Roles

1. Research Project: A. Conception, B. Organization, C. Execution; 2. Statistical Analysis: A. Design, B. Execution, C. Review and Critique; 3. Manuscript Preparation: A. Writing the First Draft, B. Review and Critique.

E.C.: Research: 1A, 1B, 1C, 3A, 3B

J.D.: Research: 1A, 1B, 2C, 3B

Y.N.M.: 1C, 3B

T.N.: 1C

C.K.: 3B

B.O.: 2A, 2B, 2C

H.S.: 1A, 1B, 1C, 3B

S.C.: 2A, 2B, 2C

A.F.‐S.: 2B.

K.K. 1A, 1B, 1C, 3B

E.N.: 3B

E.L.: 3B

Disclosures

Ethical Compliance Statement: We confirm that we have read the Journal's position on issues involved in ethical publication and affirm that this work is consistent with those guidelines.

Funding Sources and Conflict of Interest: This study was funded by the World Federation of Neurology and the International Parkinson's Disease and Movement Disorder Society. The authors report no other sources of funding and no conflicts of interest.

Financial Disclosures for the previous 12 months: Esther Cubo reports travel and speech grants from AbbVie, Allergan, and UCB. Katie Kompoliti reports consulting fees from Neurocrine, US World Meds, and Cynapsus. Elan D. Louis MD, has received research support from the National Institutes of Health, National Institute of Neurological Disorders and Stroke (NINDS) R01 NS042859 (principal investigator), NINDS R01 NS39422 (principal investigator), NINDS R01 NS086736 (principal investigator), NINDS R01 NS073872 (principal investigator), NINDS R01 NS085136 (principal investigator), and NINDS R01 NS088257 (principal investigator). The remaining authors report no sources of funding and no conflicts of interest.