U of C research calls for urgent MRIs for patients considered low risk for stroke

A new study shows urgent MRI scans are key in diagnosing patients considered low risk for minor strokes and the findings are changing how Calgary hospitals deal with those patients.

The study, led by doctors at the University of Calgary and published in JAMA Neurology, followed 1028 patients from Canada, Australia and the Czech Republic over six years.

Researchers focused on patients who were deemed low-risk for minor strokes and ministrokes, known as TIAs, because their symptoms can be difficult to diagnose.

Their symptoms may mimic other health conditions such as migraines, seizure or reactions to stress. These patients may also have traditional stroke symptoms  (such as speech problems and paralysis or numbness) lasting less than five minutes. 

"The risk is that we can miss the diagnosis of TIA if the symptoms are not clear. We can also unnecessarily treat people with medications that can potentially cause harm when they don't need them," said Dr. Shelagh Coutts, University of Calgary stroke neurologist and principal investigator.

According to Coutts, it's important doctors get that diagnosis right because the risk of a full-fledged stroke increases after a TIA.

During the six year study, patients in the low-risk group were given detailed exams by neurologists and sent for an MRI scan within eight days of first experiencing symptoms.

"We found some surprising things," said Coutts.

"We found a higher risk of stroke than we expected in this lower-risk population where we're not clear what's happening."

The MRI brain scans revealed 13.5 per cent of those with unclear symptoms had actually experienced a stroke. And in 30 per cent of cases, the diagnosis was changed based on the MRI findings.

"And so what we found was in patients where its not clear what's happening often an MRI scan can help."

Treatment changes in Calgary

The study concludes low-risk patients should receive an MRI within the first week of symptom onset and Calgary hospitals have changed their protocols as a result.

"These lower risk patients, we are now seeing more quickly than we ever used to be and we're also getting MRI scans way more quickly because of this," said Coutts.  

Drs. Margy McCullough-Hicks and Gregory Albers of Stanford University's neurology department in California wrote a journal editorial accompanying the study.  McCullough-Hicks and Albers applauded the authors for what they called an "important study."

The editorial encouraged  the stroke community to increase the use of MRI on patients like those involved in the research. Albers also declared a potential financial conflict of interest with an imaging technology company.  

'Peace of Mind' for patients

Matthew Miller, 47, discovered he'd suffered a mini-stroke earlier this year.  He woke up one morning in July and couldn't feel one of his hands.

"I tried to drink some water. It fell out of my face. I went to talk to my girlfriend and I could not speak," said Miller who was rushed by ambulance to a Calgary hospital.

Those symptoms disappeared within minutes so Miller was deemed low risk. Because of the changes that came about as a result of the study, Miller was given an urgent MRI. Once doctors discovered he'd suffered a TIA, they began treating him with medication to prevent a much bigger stroke down the line.

The findings also prompted doctors to investigate further and they discovered a hole in his heart was to blame.

"Now they can go in and patch that hole, which should hopefully greatly reduce future strokes for me," said Miller who is relieved to have a formal diagnosis and to know what's going on inside his body.

"The clarity as to what's actually going on, what has happened, and what is the path toward correcting that brings a lot of peace of mind."