| Summary
Background Neurological disorders are increasingly recognised as major causes of death and disability worldwide.
The aim of this analysis from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2016 is to
provide the most comprehensive and up-to-date estimates of the global, regional, and national burden from
neurological disorders.
Methods We estimated prevalence, incidence, deaths, and disability-adjusted life-years (DALYs; the sum of years of
life lost [YLLs] and years lived with disability [YLDs]) by age and sex for 15 neurological disorder categories (tetanus,
meningitis, encephalitis, stroke, brain and other CNS cancers, traumatic brain injury, spinal cord injury, Alzheimer’s
disease and other dementias, Parkinson’s disease, multiple sclerosis, motor neuron diseases, idiopathic epilepsy,
migraine, tension-type headache, and a residual category for other less common neurological disorders) in
195 countries from 1990 to 2016. DisMod-MR 2.1, a Bayesian meta-regression tool, was the main method of estimation
of prevalence and incidence, and the Cause of Death Ensemble model (CODEm) was used for mortality estimation.
We quantifed the contribution of 84 risks and combinations of risk to the disease estimates for the 15 neurological
disorder categories using the GBD comparative risk assessment approach.
Findings Globally, in 2016, neurological disorders were the leading cause of DALYs (276 million [95% UI 247–308])
and second leading cause of deaths (9·0 million [8·8–9·4]). The absolute number of deaths and DALYs from all
neurological disorders combined increased (deaths by 39% [34–44] and DALYs by 15% [9–21]) whereas their agestandardised rates decreased (deaths by 28% [26–30] and DALYs by 27% [24–31]) between 1990 and 2016. The only
neurological disorders that had a decrease in rates and absolute numbers of deaths and DALYs were tetanus,
meningitis, and encephalitis. The four largest contributors of neurological DALYs were stroke (42·2% [38·6–46·1]),
migraine (16·3% [11·7–20·8]), Alzheimer’s and other dementias (10·4% [9·0–12·1]), and meningitis (7·9% [6·6–10·4]).
For the combined neurological disorders, age-standardised DALY rates were signifcantly higher in males than in
females (male-to-female ratio 1·12 [1·05–1·20]), but migraine, multiple sclerosis, and tension-type headache were
more common and caused more burden in females, with male-to-female ratios of less than 0·7. The 84 risks
quantifed in GBD explain less than 10% of neurological disorder DALY burdens, except stroke, for which
88·8% (86·5–90·9) of DALYs are attributable to risk factors, and to a lesser extent Alzheimer’s disease and other
dementias (22·3% [11·8–35·1] of DALYs are risk attributable) and idiopathic epilepsy (14·1% [10·8–17·5] of DALYs
are risk attributable).
Interpretation Globally, the burden of neurological disorders, as measured by the absolute number of DALYs,
continues to increase. As populations are growing and ageing, and the prevalence of major disabling neurological
disorders steeply increases with age, governments will face increasing demand for treatment, rehabilitation, and
support services for neurological disorders. The scarcity of established modifable risks for most of the neurological
burden demonstrates that new knowledge is required to develop effective prevention and treatment strategies. |