An international team of scientists led by EPFL has developed a system that combines information from the brain’s connectome – the “wiring” between neurons – and machine learning to assess and predict the outcome of stroke victims.

When blood flow to the brain is somehow reduced or restricted, a person can suffer what we know as a stroke (from “ischemic stroke” in medical jargon). Stroke is one of those conditions that seems fairly common. This isn’t a misperception: just in Europe, there are over 1.5 million new cases each year.

Some strokes can be lethal, and when they’re not they often result in serious damage to the victim’s ability to move. In fact, stroke is one of the major causes of long-term disability today. Recovery can be a long and arduous road. Again, in Europe, under 15% of the patients achieve full recovery, leaving 3.7 million patients with persistent impairments. Clearly, this is a medical problem that needs urgent addressing.

But rehabilitation is a complicated problem to solve. Strokes can occur in different parts of the brain, affecting different brain systems, and patients who undergo rehabilitation show a “heterogeneity in outcome”, which is the medical way of saying that recovery can be very different between individual stroke victims.

“The key is to find the optimal neuro-rehabilitative strategy to maximize individual treatment outcome,” says Professor Friedhelm Hummel, a neuroscientist and Director of the Defitech Chair for Clinical Neuroengineering at EPFL’s School of Life Sciences. “If we want to address these challenges in everyday clinical practice, we have to first enhance our ability to predict the individual courses of recovery,” adds Dr Philipp J. Koch, the study’s first author.

Hummel has now led an international team of scientists into a new approach for outcome prediction that can significantly improve stroke treatment. Publishing in the journal Brain, they demonstrate a predictive method based on two powerful, cutting-edge tools: connectomes and machine learning.

The team included scientists from Sungkyunkwan University School of Medicine (Professor Y.-H. Kim), University Medical School of Geneva (Professor A. Guggisberg), Inserm Paris (Professor C. Rosso), Santa Lucia Foundation IRCCS, Rome (Professor G. Koch), and EPFL (Professor Thiran).

What is a connectome? Simply put, it’s a map of a brain’s wiring. The term itself was coined independently in 2005 by two scientists (one from Lausanne’s University Hospital) to describe the “blueprint” of how a brain’s neurons connect to each other, evoking the concept of the genome – hence, “connectome”.

To have further information, please visit the EPFL website.