, a new comprehensive analysis showed.
In 2021, neurological conditions were responsible for 443 million years of healthy life lost due to illness, disability, and premature death — a measurement known as disability-adjusted life years (DALY) — making them the top contributor to the global disease burden, ahead of cardiovascular diseases.
Some 3.4 billion people — 43% of the entire global population — had a neurological illness in 2021, the report noted.
“As the world’s leading cause of overall disease burden, and with case numbers rising 59% globally since 1990, nervous system conditions must be addressed through effective, culturally acceptable, and affordable prevention, treatment, rehabilitation, and long-term care strategies,” lead author Jaimie Steinmetz, PhD, from the Institute of Health Metrics and Evaluation (IHME), University of Washington, Seattle, said in a news release.
The findings, from the Global Burden of Disease, Injuries, and Risk Factors Study (GBD) 2021, “have important health service and policy implications and serve as evidence that global neurological heath loss has been under-recognized and is increasing and unevenly distributed geographically and socioeconomically,” the authors noted.
The study was published online in The Lancet: Neurology.
The Top 10
The top 10 contributors to neurological health loss in 2021 were stroke, neonatal encephalopathy, migraine, Alzheimer’s disease and other dementias, diabetic neuropathy, meningitis, epilepsy, neurological complications from preterm birth, autistic spectrum disorders, and nervous system cancers.
Neurological consequences of COVID-19 ranked 20th out of 37 unique conditions assessed.
In 2021, there were more than 23 million global cases of COVID-19 with long-term cognitive symptoms or Guillain-Barré syndrome, accounting for 57% of all infectious neurological disease cases and contributing to 2.48 million years of healthy life lost, the study found.
The most prevalent neurological disorders were tension-type headache (about 2 billion cases) and migraine (about 1.1 billion cases), while diabetic neuropathy is the fastest-growing of all neurological conditions.
“The number of people with diabetic neuropathy has more than tripled globally since 1990, rising to 206 million in 2021. This is in line with the increase in the global prevalence of diabetes,” co-senior author Liane Ong, PhD, from IHME, said in the release.
The data showed striking differences in the burden of neurological conditions between world regions and national income levels, with over 80% of neurological deaths and health loss occurring in low- and middle-income countries.
Regions with the highest burden of neurological conditions were central and western sub-Saharan Africa, while high-income Asia Pacific and Australasia had the lowest burden.
“Nervous system health loss disproportionately impacts many of the poorest countries partly due to the higher prevalence of conditions affecting neonates and children under 5, especially birth-related complications and infections,” co-senior author Tarun Dua, MD, with the World Health Organization (WHO) brain health unit, noted in the news release.
“Improved infant survival has led to an increase in long-term disability, while limited access to treatment and rehabilitation services is contributing to the much higher proportion of deaths in these countries,” Dr. Dua said.