A new study has shown that nocturnal heat significantly increases the risk of stroke and alerted the public to better protect themselves against the risks of climate change with increasingly frequent hot nights, as well as improve patient care.

The study, which was done using hot tropical nights measured in the Hot Night Excess Index (HNE) by researchers from Helmholtz Munich and Augsburg University Hospital, could give additional knowledge of the consequences of hot nights and also serve as a basis for further research to develop targeted preventive measures against stroke-promoting factors.

Tropical nights are defined using the HNE index which measures how much temperatures rise above a certain threshold value at night. In this study, the threshold value used is 14.6 °C and if temperatures rise above this value at night, this is categorized as a tropical night. The HNE index adds up how many degrees the temperatures are above this threshold during the night hours to determine the intensity of the heat.

Analysing data on 11,000 stroke cases from over 15 years, the researchers found out that extreme heat at night increases the risk of stroke by seven percent with elderly people and women particularly at risk with strokes of mild symptoms diagnosed in clinics after hot nights.

The team lead, environmental risks at Helmholtz Munich, Dr. Alexandra Schneider, explained that the team investigated the effects of night-time heat on the risk of stroke to understand the extent to which high night-time temperatures pose a health risk since climate change is causing night-time temperatures to rise much faster than daytime temperatures. “The earlier these preventive measures are implemented, the better. The results of the study are also of great importance for hospitals to better adapt to the frequency of strokes in the future.”

: If the weather forecast predicts a hot night, it can be expected that more cases will come to the clinics.

This allows clinics to provide more staff to care for patients as a precaution,” he said.

The study’s lead author, Dr. Cheng He, noted that the results make it clear that adjustments in urban planning and the healthcare system are extremely important and needed to reduce the risks posed by rising night-time temperatures.

Meanwhile, scientists have developed a new test to identify patients experiencing Large Vessel Occlusion (LVO) stroke with high accuracy by combining blood-based biomarkers with a clinical score.

While ischemic stroke is the obstruction of blood flow to the brain, LVO strokes are an aggressive type of ischemic stroke that happens when an obstruction occurs in a major artery in the brain. When blood supply to the brain is compromised, the lack of oxygen and nutrients causes brain cells to die within minutes leading to major medical emergencies that require swift treatments using mechanical thrombectomy.

The study led by investigators from Brigham and Women’s Hospital and published in the journal Stroke: Vascular and Interventional Neurology was carried out by targeting two specific proteins found in blood-based biomarkers of the capillary blood known as glial fibrillary acidic protein (GFAP) and D-dimer They demonstrated that the levels of these biomarkers combined with assessment could identify LVO ischemic strokes while ruling out other conditions such as bleeding in the brain.

With vastly different treatments, brain bleeds cause similar symptoms to LVO stroke, making it hard to distinguish from one another in the field. The researchers looked at data from a cohort of 323 patients coded for stroke in Florida between May 2021 and August 2022 and found that combining the levels of the biomarkers GFAP and D-dimer with assessments in less than six hours from the onset of symptoms allowed the test to detect LVO strokes with 93 per cent specificity and 81per cent sensitivity. Other findings included that the test ruled out all patients with brain bleeds, signaling that the technology may ultimately also be employed to detect intracerebral hemorrhage in the field.

A senior author and clinical fellow, Department of Neurosurgery, Brigham and Women’s Hospital, Joshua Bernstock, said, “We have developed a game-changing, accessible tool that could help ensure that more people suffering from stroke are in the right place at the right time to receive critical, life-restoring care. Mechanical thrombectomy has allowed people who otherwise would have died or become significantly disabled to be completely restored, as if their stroke never happened and so the earlier this intervention is enacted, the better the patient’s outcome is going to be. This exciting new technology has the potential to allow more people globally to get this treatment faster.”

“In stroke care, time is brain, the sooner a patient is put on the right care pathway, the better they are going to do. Whether that means ruling out bleeds or ruling in something that needs an intervention, being able to do this in a prehospital setting with the technology that we built is going to be truly transformative,” he said.

The team also sees promising potential future use of this accessible diagnostic tool in low- and middle-income countries, where advanced imaging is not always available. It might also be useful in assessing patients with traumatic brain injuries. They have also designed an interventional trial that leverages the technology to expedite the triage of stroke patients by having them bypass standard imaging and move directly to intervention.

Stroke is the leading cause of disability worldwide and the second leading cause of death, but the right early intervention can prevent severe consequences. Stroke is the leading cause of disability worldwide and the second leading cause of death, but the right early intervention can prevent severe consequences.