A new test that provides individual results can be part of an aid course for stroke survivors, who will also be tested for biomarkers associated with improved outcomes in other brain regions.
New research published in The Journal of Neurology (opens in a reader browser) – the first peer-reviewed journal from The University of Manchester – shows how, in a fraction of the cost of the PET/CT scan, measuring excitability or ‘hyperconnectivity’ in a central compartment of the brain can give a highly accurate and quantitative assessment of stroke survivors’ brain function.
Almost 100 people in England who suffered strokes aged between 30 and 64 years have been enrolled and offered the benefit of the new PET/CT scan, which is an important and cheap test for recovery after a stroke, with potential to save lives.
It is the difference between a credit card and a prescription medicine throughout the stroke recovery process, meaning patients can obtain the scan commercially, without additional engineering or training, and is the first test for stroke survivors for which travel can be covered.
The tests are carried out outside of the hospital and will detect a mechanism found in the brain which is activated during the first moments after a stroke. Researchers also have used magnetic resonance (MRI) imaging to see the blood-brain barrier (BBB) narrowing, which is a marker of brain injury which is often not detectable by the regular PET/CT scan. This marker is also a biomarker associated with tight blood-brain barrier closure.
Dr. Cathy HAM-HELESS, senior author from the University of Manchester, says: “This is the first time anyone has been able to correlate the MRI signal with brain function, but was unable to clearly see any difference between stroke survivors and healthy controls.
“This is important because it means that stroke survivors are able to receive the stroke treatment that suits them best. For doctors and stroke survivors to benefit, their brain function must improve, their symptoms become much less severe, and their function returns to normal shortly afterwards.”
These biomarkers are only present in people who have had a stroke and have returned to consciousness, but are complex throughout the whole course of a stroke. Data from glial cells has previously shown that these brain cells are important for the proper functioning of the brain, but it emerged that other important cells in the brain are also involved in supporting this recovery process.
Molecular imaging can reveal which regions of the brain a stroke victim has affected, leading to individualised therapies that target the specific regions affected.
The PET/CT scan also allows finding a link between what the patient has been sleeping and how well they are coping, how their movement is affected, etc. to how well they perform on other important tests such as memory, cognitive functioning, etc.
Professor Stephen Bate, Care Manager for the NHMRC Stroke Research Unit in Manchester, said:
The task line is closed for now as we await the results from the test in the hospital. We take the results every 10 days.”
Stroke is the leading cause of acute loss of brain function in adults over the age of 65, accounting for over 634,000 strokes a year in England and more than 500,000 in London. It is the major cause of disability in people aged over 65 and the leading cause of premature death in people over 65 years old.
The present test is cheap and simple but more advanced PET/CT scans are also carried out, which are controversial. In contrast to standard PET scans which are cost-effective, the new scanning is non-invasive and does not require a needle and requires filters to avoid unnecessary exposure to radiation (a complication, but common in conventional PET tests)
This means that it is also essential to gain increasing confidence from both a simple scan and the MRI result to decide whether or not to perform certain tests scheduled for it.
The research, funded by the NHMRC Stroke Research Fund and National Institute of Neurological Disorders and Stroke (NINDS), was conducted by Professor Stephen Bate and Professor Helen Ritchford from Manchester University, who gave a talk at the recent Brain and Government Conference.
The imaging key is a thin stick-like CT-map encased in a memory foam which uses ultrasound to produce three patterns of codes on the surface of the test subject. These code clusters contain a set of magnetic aligned spots.
NINDS has agreed to substitute these for testing subjects with the expertise pertinent for reporting a test result, which is broadly accepted across medical institutions and serious institutions worldwide.
The aim is for around 40 to 60 million people who die from stroke in the UK one day to have control of their stroke outcome through non-invasive PET/CT scan tests. The test results can predict outcome much better than regular cognitive assessments such as verbal memory, which can be a challenge.