The Current State of Parkinsonism in West Africa: A Systematic Review

Table 2

Summary of prevalence studies.

Author(s), reference	Country, geographic region	Setting, study design, study period	Population, characteristics	Diagnostic criteria used	Crude prevalence of PKS and PD	Summary findings	Study limitations
Talabi [41]	Nigeria, South-Western	Hospital, cross-sectional, 1998–2000	Population: 26,355; Neurologic cases: 781; PD cases: 4 (0.5%)	NA	PD: 15	PD is a rare cause of admission	1. Single-centre study; 2. Diagnostic criteria undefined; 3. Prevalence data reflects hospital prevalence but not true prevalence of population.; 4. Risk of referral bias as study site is a tertiary facility.
Ekenze et al. [40]	Nigeria, South-Eastern	Hospital,; cross-sectional,; 2003–2007	Population: 8440; Neurologic cases: 1249; PD cases: 14 (1.1%); Males: 10 (71.4%); Females: 4 (28.6%); Male-female ratio = 2.5 : 1; Peak age incidence >70 y	NA	PD: 166	NA	1. Single-centre study; 2. Diagnostic criteria undefined; 3. Prevalence data reflects hospital prevalence but not true prevalence of population.; 4. Risk of referral bias as study site is a tertiary facility.
Okubadejo et al. [7]	Nigeria, South-Western	Hospital,; cross-sectional,; 1996–2006	PKS cases: 124; PD cases: 98; Males: 75 (76.5%); Females: 23 (23.5%); Male-female ratio = 3.3 : 1; Age at PD onset [mean ± SD (range)]: 61.5 ± 10.0 (37–77) y; 2°PKS cases: 26; Males: 19 (73.1%); Females: 7 (26.9%); Male-female ratio = 2.7 : 1; Age at 2°PKS onset [mean ± SD (range)]: 57.5 ± 14.0 (22–78) y	Presence of at least three of the following: tremors, rigidity, bradykinesia, and postural or gait abnormality	NA	One (1) PD patient had a family history of PD in a first-degree relative.; Causes of 2°PKS: Vascular parkinsonism; Drug-induced parkinsonism; Multiple system atrophy; Lewy body dementia; Carbon-monoxide poisoning; Progressive supranuclear palsy; Hemiparkinsonism-hemiatrophy; Juvenile parkinsonism with dystonia and hemiatrophy	1. Single-centre study; 2. Risk of referral bias as study site is a tertiary facility.
Owolabi et al. [39]	Nigeria, North-Western	Hospital,; cross-sectional,; 2005–2007	Population: 6282; Neurologic cases: 980; PD cases: 4 (0.4%); Males: 4 (100.0%); Females: 0 (0.0%); Age range at study: 50–68 y	Presence of at least three of the following: tremors, rigidity, akinesia or bradykinesia, and postural instability	PD: 63	NA	1. Single-centre study; 2. Prevalence data reflects hospital prevalence but not true prevalence of population.; 3. Risk of referral bias as study site is a tertiary facility.
Femi et al. [24]	Nigeria, North-Western	Hospital,; cross-sectional,; 2007–2011	Neurologic cases: 1153; PD cases: 80 (6.9%); Males: 61 (76.3%); Females: 19 (23.7%); Male-female ratio = 3.2 : 1; Age at PD onset [mean ± SD (range)]: 58.2 ± 6.72 (39–76) y; 2°PKS cases: 16 (1.4%); Males: 13 (81.3%); Females: 3 (18.7%); Male-female ratio = 4.3 : 1; Age at 2°PKS onset [mean ± SD (range)]: 51.4 ± 10.04 (30–67) y	Presence of at least three of the following: tremors, rigidity, bradykinesia, and postural or gait abnormality	NA	Three (3) PD patients had a family history of PD in a first-degree relative.; Causes of 2°PKS: Vascular parkinsonism; Drug-induced parkinsonism; Head trauma-related parkinsonism	1. Risk of referral bias as study site is a tertiary facility.
Philip-Ephraim et al. [29]	Nigeria, South-Eastern	Hospital,; cross-sectional,; 2009–2010	Population: 699; Neurologic cases: 152; PD cases: 4 (2.6%); Males: 4 (100.0%); Females: 0 (0.0%)	NA	PD: 572	NA	1. Single-centre study; 2. Diagnostic criteria undefined; 3. Prevalence data reflects hospital prevalence but not true prevalence of population.; 4. Risk of referral bias as study site is a tertiary facility.
Eze and Kalu [31]	Nigeria, South-Eastern	Hospital,; cross-sectional,; 2012-2013	Population: 1247; Neurologic cases: 267; PD cases: 1 (0.4%); Males: 1 (100.0%); Females: 0 (0.0%)	NA	PD: 80	NA	1. Single-centre study; 2. Diagnostic criteria undefined; 3. Prevalence data reflects hospital prevalence but not true prevalence of population.; 4. Risk of referral bias as study site is a tertiary facility.
Sarfo et al. [15]	Ghana, Southern	Hospital,; cross-sectional,; 2011–2013	Neurologic cases: 1836; PKS cases: 120 (6.5%); Male-female ratio = 2.1 : 1; Age at study [median (IQR)]: 65 (58–74) y; PD cases: 102 (5.6%)	NA	NA	Causes of 2°PKS: Vascular parkinsonism; Parkinson plus syndromes (multiple system atrophy)	1. Single-centre study; 2. Diagnostic criteria undefined; 3. Risk of referral bias as study site is a tertiary facility.
Sarfo et al. [13]	Ghana, Southern	Hospital,; cross-sectional,; 2008–2013	Neurologic cases: 6494; PD cases: 33 (0.5%); Male-female ratio = 4.5 : 1; Age at study [mean ± SD]: 70.6 ± 11.5 y	NA	NA	NA	1. Single-centre study; 2. Diagnostic criteria undefined; 3. Risk of referral bias as study site is a tertiary facility.
Assadeck et al. [17]	Niger	Hospital,; cross-sectional,; 2009–2013	Neurologic cases: 1695; 2°PKS cases: 76 (4.5%); PD cases: 25 (1.5%); Males: 15 (60%); Females: 10 (40%); Male-female ratio = 1.5 : 1; Age at onset [mean (range)]: 58 (42–74) y	NA	NA	Low (1.47%) frequency of PD	1. Single-centre study; 2. Diagnostic criteria undefined; 3. Risk of referral bias as study site is a tertiary facility
Adoukonou et al. [19]	Benin, Northern	Community; cross-sectional; Jun.–Aug. 2014	Population: 1094; PKS cases: 1 (0.09%)	Presence of akineto-hypertonic syndrome and/or resting tremor and nasal-palpebral reflex inexhaustible	PKS: 91	Cause of PKS: drug-induced	1. Risk of information bias as age was self-reported in a population with high illiteracy rate; 2. Subjective signs such as pain and paresthesia may have been exaggerated or minimized.

NA: not available; crude prevalence: is given as (cases/100,000) × population; PD: Parkinson’s disease; PKS: parkinsonism; 2°PKS: secondary parkinsonism; y: years; SD: standard deviation; IQR: interquartile range.