Global, regional, and national epidemiology of neurological disorders and subcategories: incidence and disability-adjusted life years, 1990-2021

Abstract

Objectives: To multi-dimensional analyze global trends and inequalities in the burden of neurological disorders (NDs) and subcategories from 1990 to 2021, and provide clues for policymakers to formulate relevant prevention and control strategies.

Methods: Using data from the Global Burden of Disease Study 2021, we assessed trends in incidence and disability-adjusted life years (DALYs) and estimated the annual percentage change (EAPC) for NDs and their eight subcategories. Cross-country inequalities and decomposition were quantified for DALYs. Analyses were stratified by Socio-Demographic Index (SDI), age, sex, and region.

Results: Globally, age-standardized incidence (ASIR) and DALY rates (ASDR) remained stable, but marked heterogeneity existed across subcategories. Tension-type headache (ASIR: 87%) and migraine (ASDR: 40%) dominated burdens in 2021. Parkinson's disease and migraine exhibited rising trends (ASIR-EAPC: 1.09% and 0.07%; ASDR-EAPC: 0.32% and 0.05%, respectively). Females bore higher burdens for migraine, multiple sclerosis, and Alzheimer's disease and other dementias, with disparities widening in older age groups. Middle SDI regions, particularly East Asia (EAPC: 0.22%) and China (0.23%), saw accelerating ASIR. ASDR grew fastest in Western Sub-Saharan Africa (0.22%) and Zambia (0.62%). Cross-country inequality indices revealed worsening disparities, concentrating burden in high SDI countries, while idiopathic epilepsy persistently clustered in low SDI populations. Population growth (64.21%) and aging (35.33%) drove DALYs increase, with aging disproportionately impacting high- and high-middle SDI regions.

Conclusions: The burden of NDs demonstrates significant age, sex, and socioeconomic heterogeneity. Prioritizing resource equity and tailored policies is critical to achieving targets. High SDI regions require aging-focused interventions, while low/middle SDI regions need population-level strategies.

Keywords: Alzheimer’s disease and other dementias; DALYs; Headache; Idiopathic epilepsy; Neurological disorders; Parkinson’s disease.

Fig. 1

Global trends of incidence and DALYs in neurological disorders and subcategories from 1990 to 2021. A Incidence cases of subcategories diseases of neurological disorders from 1990 to 2021 (without other neurological disorders). B DALYs cases of subcategories diseases of neurological disorders from 1990 to 2021. C ASIR of subcategories diseases of neurological disorders over the last 32 years (without other neurological disorders). D ASDR of subcategories diseases of neurological disorders over the last 32 years. ASIR, age-standardized incidence rate; ASDR, age-standardized death rate; DALYs, disability-adjusted life years

Fig. 2

Global incidence and DALYs in neurological disorders and subcategories, by sex and age. A Sex-specific ratio of global incidence cases for neurological disorders and its subcategories, 1990 to 2021 (without other neurological disorders). B Sex-specific ratio of global DALYs cases for neurological disorders and its subcategories, 1990 to 2021. C Age-specific global incidence rates of neurological disorders in 1990 and 2021. D Age-specific global DALYs rates of neurological disorders in 1990 and 2021. E Age-specific sex ratio of global incidence cases for neurological disorders and its subcategories in 1990 and 2021 (without other neurological disorders). F Age-specific sex ratio of global DALYs cases for neurological disorders and its subcategories in 1990 and 2021. DALYs: disability-adjusted life years; ADODs: Alzheimer’s disease and other dementias; PD: Parkinson’s disease; IE: idiopathic epilepsy; MS: multiple sclerosis; MND: motor neuron disease; Mig: Migraine; NDs: Neurological disorders; TTH: Tension-type headache; ONDs: other neurological diseases

Fig. 3

ASR trends in neurological disorders and subcategories, by global, 5 SDIs and 21 regions. A ASIR of neurological disorders by global, 5 SDIs and 21 regions in 1990 and 2021. B ASDR of neurological disorders by global, 5 SDIs and 21 regions in 1990 and 2021. C EAPC in ASIR of neurological disorders and its subcategories from 1990 to 2021, by global, 5 SDIs and 21 regions, for both sexes (without other neurological disorders). D EAPC in ASDR of neurological disorders and its subcategories from 1990 to 2021, by global, 5 SDIs and 21 regions, for both sexes. ASIR: age-standardized incidence rate; ASDR: age-standardized DALYs rate; DALYs: disability-adjusted life years; EAPC: estimated annual percentage change; SDI: Sociodemographic Index

Fig. 4

Global trends in neurological disorders by countries and territories. A ASIR of neurological disorders in 2021. B EAPC in ASIR of neurological disorders from 1990 to 2021. C ASDR of neurological disorders in 2021. D EAPC in ASDR of neurological disorders from 1990 to 2021. ASIR: age-standardized incidence rate; ASDR: age-standardized DALYs rate; DALYs: disability-adjusted life years; EAPC: estimated annual percentage change

Fig. 5

SDI-related cross-country health inequality regression (A) and concentration (B) curves for the crude DALYs rates of neurological disorders, 1990 and 2021. CI: concentration index; DALYs: disability-adjusted life-years; SDI: sociodemographic index; SII: slope inequality index

Fig. 6

Decomposition analysis of DALYs in neurological disorders and subcategories from 1990 to 2021 by global and 5 SDIs. The black dot denotes the overall value of the change resulting from all three components. Positive values indicate increased neurological disorder DALYs attributed to each component, while negative values reflect corresponding decreases. DALYs: disability-adjusted life-years; SDI: sociodemographic index