Helping people see again

The Neuro’s Christopher Pack examines how the brain sees the world

Vision loss can be one of the after effects of stroke. A researcher at The Neuro is working on a cheap, at-home method to help stroke victims regain their ability to see.

“Sometimes patients recover their vision spontaneously, but often they don’t,” notes Christopher Pack who, as group leader of the Neural Circuits Research Group, studies how neurons represent information about the visual world. “After a stroke, there are almost always residual neuronal pathways from the eyes to the brain, which is why we think that stroke victims might be treatable. If the information is getting to the brain, their vision deficiency is something that in theory can be rehabilitated.”

Pack and his collaborators are developing a home-based rehabilitation program that just needs a computer and an internet connection. A software program provided by a Montreal software company, Article 19 Group, is undergoing tests with 24 stroke patients recruited at The Neuro’s Stroke Unit as well as at the Centre Hospitalier de l’Université de Montréal (CHUM) and at local rehabilitation centres.

The program involves simple visual tests.

“A visual stimulus appears on the screen and the subject reports whether it’s moving left or right or some other way,” says Pack. “We ask them to do this for about 30 minutes a day. Depending on what we display on the screen, the subject can be trained to use different parts of their brain. The reason that this is possible is that there are maybe 20 or 30 different structures in the brain concerned with vision. Each structure prefers a different range of stimuli, whether dots or lines or colours. By adjusting these stimuli, different parts of the brain can be engaged.”

Pack notes that plasticity in the brain allows learning by repetition. If a patient does the test over and over, they will relearn to use the area in the brain that has residual function. The exercises are the visual equivalent of physical therapy. If a stroke damages movement in a patient’s arm, a therapist would ask the patient to move the arm again and again.

“In our preliminary testing, we have seen that patients often recover some visual function,” says Pack. “It doesn’t come back to normal, but they recover the ability to see motion, for example, or they can read better, or they have less motion sickness, which is a problem with visual deficit.”

Pack admits that performing the visual exercises for 30 minutes a day is rather boring. He is looking at how to make the exercises more fun, perhaps by making them into a game.

He would like the software to be available to the public within a few years. For now, he is seeking more stroke patients who can provide enough test data to confirm his preliminary findings.

Stroke patients who might be interested in acting as subjects in Pack’s research may write to the graduate student who is coordinating the study, Asmara Awada: asmara.awada [at] mail.mcgill.ca

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The Neuro is a McGill research and teaching institute; delivering the highest quality patient care, as part of the Neuroscience Mission of the McGill University Health Centre. We are proud to be a Killam Institution, supported by the Killam Trusts.