People who experience ischaemic stroke with no previously diagnosed risk factors have been found to have underlying conditions in the majority of cases, a new study has found. 

The research revealed that 67.7 per cent of stroke patients with previously undiagnosed major risk factors (UMRF) were found to have one major risk factor.

The most common detected vascular risk factor was dyslipidaemia, an imbalance of blood fats such as high cholesterol or raised levels of triglycerides, which affected 61.4 per cent of patients. 

The second most common risk factor was high blood pressure – 23.7 per cent of patients – and one in ten (10.2 per cent) patients had atrial fibrillation, a condition which causes a fast and often irregular heartbeat.

Researchers from the Centre Vaudois, in Lausanne, Switzerland, analysed health records of 4,354 stroke patients from the ASTRAL registry from 2003 to 2018, 1,125 of whom had UMRF.

Lead author Dr André Rêgo said the study – which was presented at the European Academy of Neurology (EAN) Congress 2022 – provides important insights on major risk factors for ischaemic stroke.

“Our findings underline the importance of testing and treating blood fat imbalances such as high cholesterol and triglyceride levels, as well as blood pressure and identifying and treating those with atrial fibrillation and type 2 diabetes”, commented Dr Rêgo.

“Prior to our study there was scarce clinical information about the frequency, patient profile and stroke mechanisms in patients with acute ischaemic stroke with previously undiagnosed major vascular risk factors. 

“We hope that this study will help to identify potential stroke patients that require more intensive prevention techniques and surveillance in the future.”

Ischaemic stroke occurs when a blood clot or other blockage cuts off bloody supply to the brain and is the most common type of stroke.

Using multivariate analyses, the research found a positive association between UMRF patients and lower age, non-Caucasian ethnicity, contraceptive use in women aged under 55 and smoking for patients 55 and older. 

The research also found negative associations with antiplatelet (blood thinner) use before the stroke and higher Body Mass Index (BMI), which builds further on previous research that linked routine medication with stroke risk.

A sensor-equipped computer program called PrimSeq can accurately identify and count arm movements in people undergoing stroke rehabilitation, a new study shows. 

Now that it can do so, the next step, say the study authors, is to use the tool to define the intensity of movements that bring about the greatest recovery in patients’ ability to move independently and take care of themselves after a stroke.

Arm mobility is seriously reduced in more than half of stroke survivors, statistics show, meaning PrimSeq could play a key role in upper limb rehabilitation, pending success in clinical trials. 

Led by researchers at NYU Grossman School of Medicine, the study showed that PrimSeq was 77 per cent effective in identifying and counting the number of arm motions prescribed during rehabilitation exercises for stroke patients. 

Sensors strapped to the arms and back were used to track movements in three dimensions. 

The developers say they plan further testing on more stroke patients to refine their computer model, cut down on the number of sensors needed, and then develop a smaller prototype device that could be worn on the arm and upper body.

“Our study demonstrates that a digital tool, which is being designed to serve the same function as a smartwatch, is highly accurate in tracking the intensity of patients’ movements during stroke rehabilitation therapy,” says co-senior investigator Dr Heidi Schambra, an associate professor in the Department of Neurology and the Department of Rehabilitation Medicine at NYU Langone.

“Such an aid is desperately needed because counts made from video recordings or other wearable sensors do not offer standardized measures of precisely how much rehabilitation exercise each patient is receiving.

“Any improvements in exercise ‘dose’ received must be based on accurate, automated measures of the type and number of arm movements involved in a given exercise.”

Previous research in animals suggests that intense exercise of the upper body can promote recovery after stroke. However, research in humans shows that stroke patients receive on average one-tenth of the exercise training proven effective in animals. 

This, researchers say, is mostly because there was no easy way, until the development of PrimSeq, to accurately track their arm movements.

The new study recorded the upper body movements of 41 adult stroke patients while they performed routine rehabilitation exercises for regaining use in the arms and hands. Exercises and arm movements involved patients feeding themselves with a fork and grooming themselves with a comb.

More than 51,616 upper body movements were recorded from nine sensors, with the digital recordings of each arm movement then matched to functional categories, such as whether the movement involved reaching for an object or holding it still.

Artificial intelligence (machine learning) software was then programmed to detect patterns within the data and tie these patterns to specific movements. 

The resulting PrimSeq tool was then tested on a separate group of eight stroke patients who wore the sensors while performing various exercises.

PrimSeq was then used to see if it could accurately identify 12,545 of their recorded movements according to their function. 

The program was successful in accurately assessing the majority of movements in patients, all of whom had mild to moderate arm impairments from stroke.

“PrimSeq has state-of-the-art performance in terms of identifying and counting functional movements in stroke patients, and we are gathering more data to continue increasing its accuracy,” says co-senior investigator Dr Carlos Fernandez-Granda, an associate professor of mathematics and data science at New York University.

“As our research seeks to find optimal levels of training intensity needed for recovery, I would assert that our tool is very promising for clinical use, since the alternative is not having accurate counts at all,” says Dr Schambra. 

“If further experiments prove successful, we will of course be testing the system in clinical trials.”

The authors intend to make PrimSeq freely available to stroke rehabilitation experts worldwide and have already posted their data used to construct the program online at https://simtk.org/projects/primseq.

A new research programme to investigate the potential of Pharyngeal Electrical Stimulation (PES) in enabling stroke patients to recover their swallowing ability has gone live at its first site as part of a trial. 

The PhEAST (Pharyngeal Electrical Stimulation for Acute Stroke dysphagia Trial) study aims to help stroke patients who are unable to swallow food and drink to re-train their brain so that they can swallow independently again.

It has now gone live at the Royal United Hospitals Bath NHS Foundation Trust (RUH), as part of research which hopes to change the lives of stroke survivors, around half of whom live with swallowing problems. 

The study – led by the University of Nottingham – uses special nasal gastric tubes, which are used to feed patients, fitted with tiny electrodes. 

The electrodes are used to deliver short bursts of current directly to the muscles and nerves that are used for swallowing.

It is hoped that by stimulating these nerves, the electric current will help to re-programme the swallowing centres in the brain. The stimulation can barely be felt by patients.

A stroke can cause swallowing problems in half of patients, many of whom still have abnormal swallowing a year later. 

Swallowing problems can lead to chest infections, poor nutrition, the need for a feeding tube inserted into the stomach, long hospital stays and disability.

Having a long-term feeding tube reduces quality of life and adds to the physical, mental and emotional cost of stroke.

The study will aim to recruit 800 participants across sites in the UK, Austria, Denmark and Germany. The first participant has just been recruited from Nottingham University Hospitals NHS Trust, and RUH is the first site. 

Professor Philip Bath, from the Stroke Trials Unit in the School of Medicine at Nottingham, is leading the study. 

“Swallowing problems are very common after stroke and yet have no proven treatment,” he said. 

“We are delighted to be starting the PhEAST trial in Nottingham and believe that it has an excellent chance of showing that pharyngeal electrical stimulation improves swallowing after stroke and so could benefit many people in the NHS.”

Emma Paulett, a speech and language therapist at the RUH, who is helping to run the research, said: “We are delighted that the RUH has been chosen to take part in such an important piece of research, which we hope will make a really positive difference to the recovery of stroke patients.

“This really is a groundbreaking study which will be using the very latest in medical technology to benefit some of our most seriously ill patients.

“The RUH already has an excellent reputation for its research, and it reflects very well on the Trust that we are the first trial site in the country to go live with such an important study.”