Detecting, timing and tracking a stroke are the most crucial and difficult issues for health professionals dealing with one of the nation’s top killers – and a University of Queensland study is making all this so much easier.
Stroke is the third most common cause of death in Australia, and is most often caused by a blood clot in the brain.
Senior research officer and neurologist Dr Michael Walsh and his team are at the forefront of the development of a predictive model for strokes being put together by UQ.
Dr Walsh says determining the time of a stroke is critical when deciding on treatment and medication for the patient.
Traditionally CAT (computerised axial tomography) scans have been used to find the location of the clot in the brain, but this type of imaging gives no information on when the stroke occurred – and timing is everything.
Dr Walsh said the critical timeframe for administering medication to dissolve a clot in the brain was within three hours (perhaps six in some cases) of the initial stroke.
“After this the brain becomes ‘mushy’ and if you then dissolve the clot, it can bleed into the brain,’’ Dr Walsh said. “If someone wakes up with a stroke, no one has any idea of when it started.’’
Predictive modelling allows a medical team to determine how much of the brain “isn’t happy’’. This means they can see not only the clot, but also how much of the brain tissue around the clot has been affected.
Dr Walsh said the technology the team uses to collect the data include MR imaging (magnetic resonance imaging ie perfusion and diffusion imaging - both of which detect blood supply to the brain), sodium imaging and EEG imaging (electroencephalogram).
“This combination of techniques – perfusion, diffusion and sodium imaging – are specific to our facility. We’re running a concurrent set of studies, and we’re acquiring the data then using it to answer a number of important questions,’’ Dr Walsh said.
The team is based at the University of Queensland’s Centre for Magnetic Resonance, CMR. They perform their studies at the Wesley and Royal Brisbane hospitals, where three dedicated research MRI machines are based.
The study began in April, 2002, and is running until at least 2004.
The benefits of the study include:
1. a better understanding of the mechanism of stroke;
2. through use of the MR machines chemical measurements can be taken as opposed to drilling a hole in the patients head to collect a sample.
3. treating doctors are given a better idea of the location of the stroke-causing clot and the time when the stroke happened; and
4. better administration of medicine without doing further harm.
The research team includes: Dr Walsh, Dr Jon Chalk, Mr Rowen Gillies, Mr Mark Strudwick and Mr Stephen Rose.
For more details please contact Dr Walsh on 0412 126 321, after January 20.
