Global, regional, and national burden of disorders affecting the nervous system, 1990-2021: a systematic analysis for the Global Burden of Disease Study 2021.
Level 3 - non-randomized controlled study
Longitudinal population-based epidemiological modeling study across 204 countries and territories (design analogy)
PubMed 38493795 · doi:10.1016/S1474-4422(24)00038-3
What was done
Using framework data from the Global Burden of Disease Study 2021, the authors modeled global, regional, and national health loss across 204 countries and territories from 1990 to 2021. The analysis covered 37 unique conditions affecting the nervous system, including primary neurological diseases, neurodevelopmental disorders, and isolated neurological sequelae of congenital, neonatal, infectious (e.g., COVID-19, malaria, Zika), and diabetic conditions. Metrics estimated by age and sex with 95% uncertainty intervals (UIs) included mortality, prevalence, years lived with disability (YLDs), years of life lost (YLLs), and disability-adjusted life-years (DALYs), with a comorbidity correction applied for total prevalence.
What was found
In 2021, disorders affecting the nervous system ranked as the leading global group cause of DALYs at 443 million (95% UI 378 to 521 million), affecting 3.40 billion individuals (95% UI 3.20 to 3.62 billion), or 43.1% (95% UI 40.5 to 45.9%) of the global population. Between 1990 and 2021, absolute global DALY counts rose by 18.2% (95% UI 8.7 to 26.7%). Age-standardised death rates dropped by 33.6% (95% UI 27.6 to 38.8%) and age-standardised DALY rates dropped by 27.0% (95% UI 21.5 to 32.4%), while age-standardised prevalence changed minimally (+1.5%, 95% UI 0.7 to 2.4%). The top 10 conditions by age-standardised DALYs in 2021 were stroke, neonatal encephalopathy, migraine, Alzheimer's disease and other dementias, diabetic neuropathy, meningitis, epilepsy, neurological complications from preterm birth, autism spectrum disorder, and nervous system cancer.
Why it matters
By incorporating neurodevelopmental conditions and secondary neurological sequelae alongside traditional neurological disorders, this study demonstrates that nervous system health loss represents the leading collective contributor to global disease burden.
Limits
The abstract does not provide details on specific primary data coverage, measurement instruments, or data gaps across lower-income regions. As an epidemiological modeling exercise, results rely heavily on statistical imputation and disease modeling assumptions in areas lacking comprehensive vital registration or surveillance data.
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- supports Brain diseases have become the world's leading source of disability.