Prevalence, treatment and clinical outcomes of Parkinson’s disease in Nigeria: A systematic review

Parkinson’s disease (PD) is a progressive neurodegenerative disease with increasing global prevalence, including in Nigeria. There are few published data on PD prevalence, treatment, and outcomes in Nigeria. Nigeria struggles with shortages of neurologists, underdeveloped diagnostics, and limited availability of medications and rehabilitation. This systematic review consolidates knowledge in PD in Nigeria and provides information regarding its prevalence, treatment, and clinical outcomes. Based on PRISMA guidelines and PROSPERO-registered protocols (CRD42024553834), searches across several databases yielded 10 studies from 2003 to 2020 across multiple Nigerian areas. Among hospital-based neurological populations, PD accounted for 0.5–9% of neurological admissions; one single-center study reported hospital-based proportions of 50–90 per 1000 neurological patients (not a population prevalence estimate), with a male-to-female ratio of approximately 3.2:1 and the mean age of onset ranging from 45 to 68.8 years across studies. The diagnosis was often delayed by about 12 months. Complications such as aspiration pneumonia and sepsis were common during hospitalizations. Levodopa was the primary treatment, its cost and availability limiting its use. Non-motor symptoms were poorly mentioned, and rehabilitation services were seldom available. PD reporting was higher in southern Nigeria according to regional variations. Limited specialist access, delayed diagnosis, and inadequate treatment have overall contributed to poor clinical outcomes. Strengthening health infrastructure, strengthening neurologist education programs, and increasing access to affordable treatments are crucial. Large-scale studies and epidemiological research are also needed to explore the genetic and environmental factors underlying PD in Nigeria.