Climate change will affect the health of patients with neurological conditions, according to a study published in The Lancet Neurology. The authors emphasise the need to understand the impact of climate change on patients to help protect their health and prevent worsening inequalities.
For this study, a team from UCL, London, analysed 332 papers published between 1968 and 2023 to determine how much climate change can affect patients with 19 different neurological conditions, including stroke, migraine, Alzheimer’s, meningitis, epilepsy, and multiple sclerosis. The team also analysed the impact of climate change on common psychiatric disorders, such as depression, anxiety, and schizophrenia.
“There is clear evidence for an impact of the climate on some brain conditions, especially stroke, and infections of the nervous system. The climatic variation that was shown to affect brain diseases included extremes of temperature (both low and high), and greater temperature variation throughout the course of day – especially when these measures were seasonally unusual,” said Professor Sanjay Sisodiya, UCL’s Queen Square Institute of Neurology. “Nighttime temperatures may be particularly important, as higher temperatures through the night can disrupt sleep. Poor sleep is known to aggravate a number of brain conditions.”
Results showed an increase in admissions, disability, and mortality after a stroke in high temperatures and heat waves. This may affect more patients with neurological problems. For example, patients with dementia may struggle to recognise and adapt to situations of extreme temperature (e.g., heat-related illness or hypothermia) and weather events (e.g., flooding or wildfires), as cognitive impairment can limit their ability to respond to their surroundings.
“Reduced awareness of risk is combined with a diminished capacity to seek help or to mitigate potential harm, such as by drinking more in hot weather or by adjusting clothing. This susceptibility is compounded by frailty, multimorbidity, and psychotropic medications. Accordingly, greater temperature variation, hotter days, and heatwaves lead to increased dementia-associated hospital admissions and mortality,” the authors wrote in the article.
“This work is taking place against a worrying worsening of climatic conditions, and it will need to remain agile and dynamic if it is to generate information that is of use to both individuals and organisations. Moreover, there are few studies estimating health consequences on brain diseases under future climate scenarios, making forward planning challenging,” said Prof Sisodiya. “The whole concept of climate anxiety is an added, potentially weighty, influence: many brain conditions are associated with a higher risk of psychiatric disorders, including anxiety, and such multimorbidities can further complicate impacts of climate change and the adaptations necessary to preserve health. But there are actions we can and should take now.”
The new article is published to coincide with The Hot Brain 2: climate change and brain health event, is led by Professor Sisodiya, and jointly organised by UCL and The Lancet Neurology.