Up & Coming
Thalia Field, MD
From Geology to Stroke Neurology
When Calgary native and recent recipient of a 2012 AAN Clinical Research Training Fellowship, Thalia Field, MD, entered college, she dreamt of studying geology. But Dr. Field found herself at Harvard University in Cambridge, MA — far from the majestic beauty of the Rockies — and with no mountains in sight, her plans took a vastly different turn.
Dr. Field returned to Canada to attend Dalhousie Medical School in Halifax, Nova Scotia, in 2003. Currently, she is completing her fifth year of adult neurology residency at the University of British Columbia (UBC) Faculty of Medicine in Vancouver, and anticipates starting a Master's of Health Science (clinical epidemiology) this fall at the UBC School of Population and Public Health.
Here, she talks to Neurology Today about her plans to research blood pressure variability in subcortical strokes and why she may have had a harder time waking up for class than many of her undergraduate schoolmates.
WHAT IS YOUR RESEARCH QUESTION?
We will be looking at the effects of blood pressure variability in a cohort of patients from the SPS3 trial, which is the study for Secondary Prevention of Small Subcortical Strokes.
There is preliminary evidence that blood pressure variability — regardless of patients' underlying mean blood pressure — may affect their neurological and cardiovascular outcomes with higher rates of stroke, myocardial infarction, a greater burden of white matter disease on MRI.
The reasons for this relationship are unknown and difficult to ascertain, particularly since stroke has a number of different mechanisms. What's exciting about our project is we're going to be looking at blood pressure variability in a cohort of subjects who have a uniform stroke mechanism — all of the subjects in the SPS3 trial are enrolled after they have had an underlying small vessel infarct, which is confirmed on MRI, and they are then randomized to either single or dual antiplatelet medications as well as more aggressive versus less aggressive blood pressure targets. We'll be looking at the effects of blood pressure variability on those patients' clinical outcomes in terms of recurrent infarction, as well as cognitive outcomes over time (these patients have had detailed cognitive follow-up during the SPS3 trial).
Additionally, we'll have an opportunity to look at relationship between other outcomes and blood pressure variability that haven't yet been examined in previous trials, including levels of inflammatory markers, and burden of microbleeds.
WHAT DO YOU HOPE TO FIND?
There's a wide demographic variation in these trials — only half of the patients enrolled are Caucasian, and the other half are mostly black and Hispanic and there is a range of ages, baseline vascular risk factors and antihypertensive regimens. So, we'll get the chance to study whether there are any underlying trends which might be linked towards blood pressure variability.
It'll also be interesting to see over the long term what the implications of blood pressure variability are for small vessel disease in general. Small vessel disease often doesn't happen in isolation — there are small vessels in the kidney, brain and eye. I think over time, it will be intriguing to see whether variability is an epiphenomenon of small vessel dysfunction or whether it's contributing to small vessel dysfunction in and of itself. The pathophysiology of the relationship is uncertain and it will be exciting to discover why this may be happening and if, for example, it could be a phenomenon of renal dysfunction and calcium homeostasis problems or whether it could be linked to underlying mitochondrial dysfunction. There are so many different aspects to explore in the future.
WHO ARE YOUR RESEARCH MENTORS?
I have had a number of wonderful mentors since I became interested in stroke neurology many years ago. Dr. Oscar Benavente came from San Antonio in the middle of my residency and he's the most encouraging, patient, intelligent man. He's very committed to stroke patients and also to resident education. He's been very helpful in my understanding of the mechanics of operating large clinical trials and also in understanding underlying research methodology and evidence-based medicine.
I'm also very grateful to the other mentors that have encouraged my work — particularly Dr. Michael Hill at the Calgary Stroke Program, my mentors at Dalhousie, the stroke team at Vancouver General Hospital, as well as Dr. Jon Stoessl, my division head at UBC.
WERE YOU ALWAYS INTERESTED IN NEUROLOGY?
No, growing up in Calgary, I thought the mountains were very beautiful and that it would be interesting to study geology. One early summer in my undergrad, when I was doing geology field camp, I thought about how these geological formations have been made over millions of years and would go on to outlast human beings. I decided then that it might be more meaningful for me personally to do something on a more human time scale.
So, the next time I was deciding between summer jobs: looking for meteorites by myself in Northern Alberta or working with the Calgary Stroke Program, I chose the stroke program. That was my first contact with tPA, which had recently been introduced, so it was a very exciting time in stroke and it left a deep impression on me.
DID ANY PATIENTS INSPIRE YOU?
Seeing my first tPA patient was very inspiring for me. tPA doesn't always work perfectly but I saw a patient with a dramatic hemispheric syndrome recover significantly within the hour when they'd given the clotbuster. Watching his wife the whole time — first responding to the incredible disability that her husband had and then to the dramatic change that happened right in front of her eyes — was deeply striking for me.
TELL US SOMETHING ABOUT YOURSELF THAT MIGHT SURPRISE OUR READERS.
When I was an undergraduate at Harvard, for four years, I used to have a radio show in the middle of the night. It was an indie rock show, and they were the sort of department that insisted on playing things that you could not hear on other stations — we had to undergo a pretty intense training process, listening to certain obscure or important records and then having writing assignments about them.
It was fun except, for whatever reason, all the premed courses were really early in the morning. I used to have the last rock slot on the radio, which is between 2:30 AM and 5 AM, and then I had a chemistry class at 8 AM the next morning — I would not recommend that to anyone!
AAN Clinical Research Training Fellowships are funded by American Academy of Neurology and the American Academy of Neurology Foundation, and provide $55,000 per year for two years, plus $10,000 per year for tuition to support formal education in clinical research methodology at the fellow's institution or elsewhere. Twelve fellowships were awarded for 2012, and more than 80 training fellowships have been awarded through the program since its inception in 1996. For more information about the program, visit http://bit.ly/egrG8L.