An important new study released by The Lancet Neurology shows that, in 2021, more than 3 billion people worldwide were living with a neurological condition. The World Health Organization (WHO) contributed to the analysis of the Global Burden of Disease, Injury and Risk Factor (GBD) 2021 data.
Neurological diseases are now the leading cause of ill health and disability worldwide. The total amount of disability, illness and premature death (known as disability-adjusted life years, DALYs) caused by neurological conditions has increased by 18% since 1990.
More than 80% of neurological deaths and health loss occur in low- and middle-income countries, and access to treatment varies widely: high-income countries have up to 70 times more professional neurologists per 100,000 people than low- and middle-income countries.
Neurological diseases cause great suffering to individuals and families affecting and robbing communities and economies of human capital. This study should serve as an urgent call to action to scale up targeted interventions that will enable the growing number of people living with neurological conditions to access the quality care, treatment and rehabilitation they need. It is more important than ever to ensure that brain health is better understood, valued and protected, from early childhood to later life.”
Dr. Tedros Adhanom Ghebreyesus, WHO Director-General
The top ten neurological conditions contributing to loss of health in 2021 were stroke, neonatal encephalopathy (brain damage), migraine, dementia, diabetic neuropathy (nerve damage), meningitis, epilepsy, neurological complications from premature childbirth, autism spectrum disorder and nervous system cancers.
Overall, neurological conditions cause more disability and loss of health in men compared to women, but there are some conditions such as migraine or dementia where women are disproportionately affected.
Since 1990, the absolute number of people living with or dying from neurological diseases has increased, while age-standardized DALY rates have decreased. This means that increases in absolute numbers are mainly due to demographic changes and people living longer.
Diabetic neuropathy was the fastest growing neurological condition. The number of people with diabetic neuropathy has more than tripled worldwide since 1990, reaching 206 million cases in 2021. This increase is in line with the global increase in diabetes. Other conditions such as neurological complications from COVID-19 (for example, cognitive impairment and Guillain-Barré syndrome) did not exist in the past and now account for over 23 million cases.
At the same time, the neurological burden and loss of health due to other diseases has decreased by 25% or more since 1990 as a result of improved prevention (including vaccines), care and research: tetanus, rabies, meningitis, neural tube defects, stroke, neurocysticercosis ( parasitic infection affecting the central nervous system), encephalitis (inflammation of the brain) and neonatal encephalopathy (brain damage).
The study also looked at 20 modifiable risk factors for potentially preventable neurological conditions such as stroke, dementia and idiopathic intellectual disability.
Eliminating key risk factors – notably, high systolic blood pressure and environmental and household air pollution – could prevent up to 84% of stroke DALYs. Similarly, preventing lead exposure could reduce the burden of idiopathic intellectual disability by 63.1%, and reducing high fasting plasma glucose levels could reduce the burden of dementia by 14.6%. Smoking contributed significantly to the risk of stroke, dementia and multiple sclerosis.
More investment is needed to improve treatment, care and quality of life
At the World Health Assembly in 2022, Member States endorsed the Intersectoral global plan of action on epilepsy and other neurological disorders 2022–2031 (IGAP) with an ambitious scope to address long-neglected neurological disorders.
“The Intersectoral Global Action Plan 2022–2031 sets out a roadmap for countries to improve the prevention, early recognition, treatment and rehabilitation of neurological disorders. health, improved support for the health care workforce and adequate services,” said Dévora Kestel, Director, WHO Division of Mental Health and Substance Use.
IGAP sets out strategic goals and objectives to improve access to treatment, care and support for people with neurological disorders. implement strategies to promote brain health and prevent disease; strengthen research and data; and emphasize a public health approach to epilepsy and other neurological disorders.
