The first question people ask after suffering a stroke is: “Why?”

A straightforward question, but for 4 in 10 stroke survivors, it’s also unanswerable. These are the people for whom routine tests reveal no identifiable cause for the blood clot that may lead to their disability and premature death. And without an identifiable cause of stroke, how are doctors to prevent the next one?

Every stroke happens for a reason, even “cryptogenic” strokes. For approximately 6% of cryptogenic stroke patients, the cause is cancer which has gone undetected. Currently, there is no proven method for spotting cancer among cryptogenic stroke patients. We hope to change that.

We want to see if a test called 18F-fluorodeoxyglucose positron emission/computed tomography (FDG PET/CT) can find more cancers in patients with unexplained strokes compared to routine care alone, leading to earlier diagnosis and treatment.

FGD PET/CT is an ideal complement to routine testing after stroke; it is non-invasive, it examines the whole body, and it has been used in the past to diagnose certain types of cancer and unexplained blood clots.

Our first step is the INCOGNITO Pilot Study, which brings together experts in stroke, blood clotting, nuclear medicine, research methods, and people who have survived cancers and strokes. This feasibility study will help doctors and researchers understand the best way to use FDG PET/CT testing to look for cancer in these high-risk stroke patients.

The next step is to conduct a large, randomized trial to compare the cancer-finding potential of routine post-stroke testing with testing that includes FDG PET/CT. It will also help us expand our research program to include a larger group of cryptogenic stroke patients from hospitals across Canada.

Our ultimate goal is improved testing, timely answers, and saved lives.