The number of people living with, and dying from, conditions that affect the brain such as stroke, dementia, migraines, epilepsy and nervous system cancers, has increased globally by 18% in the last three decades, analysis suggests.
In 2021, 3.4 billion people worldwide experienced neurological conditions, making it the leading cause of ill health and disability globally, according to research published in the Lancet Neurology journal.
Scientists said an ageing global population as well as increased exposure to environmental, health and lifestyle risk factors are likely to be the cause.
The most prevalent neurological disorders in 2021 were tension headaches – with around two billion cases – and migraines – with 1.1 billion cases, the researchers said.
Diabetic neuropathy – where diabetes causes damage to the nerves – was found to be the fastest-growing of all neurological conditions.
Dr Liane Ong from the Institute for Health Metrics and Evaluation (IHME) at the University of Washington, US, who is a co-author on the study, said: “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.”
The researchers used a measurement known as DALYs (disability-adjusted life years) to assess years of healthy life lost due to disability or premature death.
They found that over the past 31 years, the overall amount of healthy life lost due to neurological conditions increased from around 375 million years in 1990, to 443 million years in 2021.
Dr Tarun Dua, of the World Health Organisation’s Brain Health Unit, who co-authored the study, said this has disproportionately impacted the poorest countries, partly due to birth-related complications and infections affecting newborns and young children.
Meanwhile figures from Brain Research UK show one in six people have some form of neurological condition, with 2.6 million people living with the effects of traumatic brain injury or stroke.
There are more than 944,000 people in the UK who have dementia, with the numbers expected to rise to more than a million by 2030.
The researchers said that as many of these conditions lack cures, prevention needs to be a top priority.
According to the team’s analysis, modifying 18 risk factors over a person’s lifetime – most importantly high blood pressure – could prevent 84% of global disabilities, illnesses, and premature deaths, from stroke.
Additionally, reducing high blood sugar levels to normal could reduce the burden of dementia by around 15%, the researchers said.
Lead author Dr Jaimie Steinmetz, from IHME, said: “We hope that our findings can help policymakers more comprehensively understand the impact of neurological conditions on both adults and children to inform more targeted interventions in individual countries, as well as guide ongoing awareness and advocacy efforts around the world.”
Commenting on the study, Dr Leah Mursaleen, head of research at Alzheimer’s Research UK, who was not involved, described the findings as “really concerning” and “underline the need for urgent action”.
She said: “Due in part, to our ageing society, dementia rates are on the rise.
“We know from our own analysis, published last year, that if nothing changes, one in two of us in the UK will be affected by dementia, either by developing the condition ourselves, caring for a loved one or both.”
Dr Mursaleen added: “However, if we’re to deliver a cure we cannot be complacent.
“Whilst research is continuously moving forward, we need governments and health systems to follow if we have any chance of stopping these devastating diseases.
“Ahead of the next general election, we are calling for ambitious commitments to tackle the increasing pressure that dementia places on society, the NHS, and the economy, and pave the way to a society in which people are free from the fear and heartbreak of this devastating condition.”
