Operationalization of DSM-5 criteria for major and mild neurocognitive disorder: Results from LASI-DAD (N = 4096).

Operationalization of DSM-5 criteria for major and mild neurocognitive disorder: Results from LASI-DAD (N = 4096).</p

Cross-tabulation of CDR scores with DSM-5 algorithmic neurocognitive disorder: Results from LASI-DAD (N = 2390).

Cross-tabulation of CDR scores with DSM-5 algorithmic neurocognitive disorder: Results from LASI-DAD (N = 2390).</p

Demographic characteristics of the LASI-DAD sample (N = 4096).

Demographic characteristics of the LASI-DAD sample (N = 4096).</p

Prevalence of major and mild neurocognitive disorder by demographic characteristics using orientation as a cognitive domain to define neurocognitive disorder: Results from LASI-DAD (N = 4096).

Prevalence of major and mild neurocognitive disorder by demographic characteristics using orientation as a cognitive domain to define neurocognitive disorder: Results from LASI-DAD (N = 4096).</p

Agreement between DSM-5 neurocognitive disorder Algorithm and CDR ratings: Results from LASI-DAD (N = 2390).

Agreement between DSM-5 neurocognitive disorder Algorithm and CDR ratings: Results from LASI-DAD (N = 2390).</p

Cross-tabulation of CDR scores with DSM-5 algorithmic neurocognitive disorder using orientation as a domain to define neurocognitive disorder: Results from LASI-DAD (N = 2390).

Cross-tabulation of CDR scores with DSM-5 algorithmic neurocognitive disorder using orientation as a domain to define neurocognitive disorder: Results from LASI-DAD (N = 2390).</p

Prevalence of major and mild neurocognitive disorder by demographic characteristics: Results from LASI-DAD (N = 4096).

Prevalence of major and mild neurocognitive disorder by demographic characteristics: Results from LASI-DAD (N = 4096).</p

Global, regional, and national burden of disorders affecting the nervous system, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021

Background: Disorders affecting the nervous system are diverse and include neurodevelopmental disorders, late-life neurodegeneration, and newly emergent conditions, such as cognitive impairment following COVID-19. Previous publications from the Global Burden of Disease, Injuries, and Risk Factor Study estimated the burden of 15 neurological conditions in 2015 and 2016, but these analyses did not include neurodevelopmental disorders, as defined by the International Classification of Diseases (ICD)-11, or a subset of cases of congenital, neonatal, and infectious conditions that cause neurological damage. Here, we estimate nervous system health loss caused by 37 unique conditions and their associated risk factors globally, regionally, and nationally from 1990 to 2021. Methods: We estimated mortality, prevalence, years lived with disability (YLDs), years of life lost (YLLs), and disability-adjusted life-years (DALYs), with corresponding 95% uncertainty intervals (UIs), by age and sex in 204 countries and territories, from 1990 to 2021. We included morbidity and deaths due to neurological conditions, for which health loss is directly due to damage to the CNS or peripheral nervous system. We also isolated neurological health loss from conditions for which nervous system morbidity is a consequence, but not the primary feature, including a subset of congenital conditions (ie, chromosomal anomalies and congenital birth defects), neonatal conditions (ie, jaundice, preterm birth, and sepsis), infectious diseases (ie, COVID-19, cystic echinococcosis, malaria, syphilis, and Zika virus disease), and diabetic neuropathy. By conducting a sequela-level analysis of the health outcomes for these conditions, only cases where nervous system damage occurred were included, and YLDs were recalculated to isolate the non-fatal burden directly attributable to nervous system health loss. A comorbidity correction was used to calculate total prevalence of all conditions that affect the nervous system combined. Findings: Globally, the 37 conditions affecting the nervous system were collectively ranked as the leading group cause of DALYs in 2021 (443 million, 95% UI 378–521), affecting 3·40 billion (3·20–3·62) individuals (43·1%, 40·5–45·9 of the global population); global DALY counts attributed to these conditions increased by 18·2% (8·7–26·7) between 1990 and 2021. Age-standardised rates of deaths per 100 000 people attributed to these conditions decreased from 1990 to 2021 by 33·6% (27·6–38·8), and age-standardised rates of DALYs attributed to these conditions decreased by 27·0% (21·5–32·4). Age-standardised prevalence was almost stable, with a change of 1·5% (0·7–2·4). The ten conditions with the highest age-standardised DALYs in 2021 were stroke, neonatal encephalopathy, migraine, Alzheimer's disease and other dementias, diabetic neuropathy, meningitis, epilepsy, neurological complications due to preterm birth, autism spectrum disorder, and nervous system cancer. Interpretation: As the leading cause of overall disease burden in the world, with increasing global DALY counts, effective prevention, treatment, and rehabilitation strategies for disorders affecting the nervous system are needed. Funding: Bill & Melinda Gates Foundation

Global, regional, and national burden of epilepsy, 1990–2016: a systematic analysis for the Global Burden of Disease Study 2016

Global, regional, and national burden of epilepsy, 1990–2016: a systematic analysis for the Global Burden of Disease Study 201

The Burden of Dementia due to Down Syndrome, Parkinson's Disease, Stroke, and Traumatic Brain Injury: A Systematic Analysis for the Global Burden of Disease Study 2019

Background: In light of the increasing trend in the global number of individuals affected by dementia and the lack of any available disease-modifying therapies, it is necessary to fully understand and quantify the global burden of dementia. This work aimed to estimate the proportion of dementia due to Down syndrome, Parkinson’s disease, clinical stroke, and traumatic brain injury (TBI), globally and by world region, in order to better understand the contribution of clinical diseases to dementia prevalence. Methods: Through literature review, we obtained data on the relative risk of dementia with each condition and estimated relative risks by age using a Bayesian meta-regression tool. We then calculated population attributable fractions (PAFs), or the proportion of dementia attributable to each condition, using the estimates of relative risk and prevalence estimates for each condition from the Global Burden of Disease Study 2019. Finally, we multiplied these estimates by dementia prevalence to calculate the number of dementia cases attributable to each condition. Findings: For each clinical condition, the relative risk of dementia decreased with age. Relative risks were highest for Down syndrome, followed by Parkinson’s disease, stroke, and TBI. However, due to the high prevalence of stroke, the PAF for dementia due to stroke was highest. Together, Down syndrome, Parkinson’s disease, stroke, and TBI explained 10.0% (95% UI: 6.0–16.5) of the global prevalence of dementia. Interpretation: Ten percent of dementia prevalence globally could be explained by Down syndrome, Parkinson’s disease, stroke, and TBI. The quantification of the proportion of dementia attributable to these 4 conditions constitutes a small contribution to our overall understanding of what causes dementia. However, epidemiological research into modifiable risk factors as well as basic science research focused on elucidating intervention approaches to prevent or delay the neuropathological changes that commonly characterize dementia will be critically important in future efforts to prevent and treat disease