Brain bypass surgery sparks restoration of lost brain tissue

In cases where blood flow is reduced to the brain as a result of diseased blood vessels, patients experience a progressive loss of brain tissue. This loss of tissue, which comprises the grey matter of the brain, is believed to lead to decreased neurocognitive function (i.e. types of thinking, such as perception, memory, awareness, capacity for judgement) and may hasten the onset of dementia.

At approximately 11 months after patients in the study underwent brain bypass surgery, aimed at restoring blood flow to the brain, researchers observed a 5.1percent increase in the thickness of the brain tissue on MRI scans.

"We were pretty astounded when we saw the results because they were quite unexpected," said Dr. Tymianski. "Our goal with the surgery was to halt further loss of brain tissue due to strokes, so it was remarkable to see the loss was actually reversed."

This is the first surgical treatment which has been shown to restore lost brain tissue. The average age of the patients in the study was 41 years old.

"The re-growth of brain tissue has only been observed in an extremely limited number of circumstances," said Dr. Tymianski. "We consider this so important because one of the most important health issues facing our population is chronic cerebrovascular disease, which leads to neurocognitive impairment and reduces quality of life."

Dr. Michael Tymianski is a neurosurgeon at the Krembil Neuroscience Centre specializing in neurovascular diseases, Director of the Neurovascular Therapeutics Program at the University Health Network and is a senior scientist at the Toronto Western Research Institute.

The full study is published online in the journal Stroke.

Provided by University Health Network