News

Scientists help Stroke Victims look into the Dark

(27 October 2006)

In the UK around 120,000 people a year will suffer from a stroke, and it is the third most common cause of death and the single most common cause of severe disability.

Typically, we associate strokes with limb paralysis and impaired speech, but 20% of those who suffer from a stroke will end up with a visual defect called Hemianopia, a partial blindness caused by damage to part of the brain called the primary visual cortex. With the help of Newcastle upon Tyne Hospitals NHS Foundation Trust and South Tees Hospitals NHS Trust, researchers at Durham University have been examining Hemianopia to find new ways to help patients whose vision has been affected by strokes. Although Hemianopia is not total blindness, it is a very disabling condition. This can leave patients unable to see anything in as much as half of their field of vision, so they have difficulty in locating things, have problems reading and coping with traffic on the street, and can become disoriented in new or crowded environments such as supermarkets. Durham University’s Cognitive Neuroscience Research team based in the Wolfson Research Institute at Queen’s Campus, Stockton, are working with consultants Gavin Young and Paul McKee from South Tees and Professor David Mendelow from Newcastle upon Tyne Hospitals Trust. Together they have been developing and testing ways of training Hemianopia patients to use their remaining vision in different ways to enable them to cope better with the condition. Dr Thomas Schenk who is leading the research said: “Hemianopia is incurable as it is impossible to actually repair the brain damage and thus, restore the vision. What we are doing is helping patients use the vision they do have, in a more efficient way to actually compensate for the partial blindness. “We do this by training them to scan their environment, looking into the blind areas with the part of their eye that functions. This then helps them avoid bumping into obstacles, being able to monitor traffic and also being able to read again. All of which could radically improve the quality of life of a hemianopia sufferer.” Ken Smith, 71, from Redcar, suffered a mini-stroke in August last year, and later had a full stroke a month later. He has just completed his treatment at the University and said: “I really enjoyed the training programme, it was very interesting. “At the beginning of the course I was told that the course wouldn’t improve my sight but would help me make better use of the sight I did have. I think this has happened and I have found the treatment to be beneficial. “Before when I was reading I would miss the left hand side of the page and at meal times I would leave all the food on the left hand side of my plate. I am now looking more to the left and take more notice of what is there, and I finish all my food!” At the moment there is no specific treatment for Hemianopia available on the NHS, but Dr Schenk’s team hope their new methods of training patients could be offered as an effective treatment. Dr Daniel Smith, Research Associate at the University said: “While treatments such as physiotherapy are widely available to stroke victims who have problems with movements, the majority of patients who suffer partial blindness as a result of a stroke do not receive any treatment, this is why we started the research.” The training programme teaches patients, in a total of 15 hours, to move their eyes to scan the areas of blindness, so they develop a way of compensating for their visual deficit. The programme doesn’t return the patient’s vision but teaches them coping strategies to deal with their blind spot. Daniel added: “Patients with hemianopia typically make many, very small eye movements when looking into their blind field. The treatment teaches people to make much larger eye movements, allowing them to quickly scan more of their environment. This will help them build a more comprehensive view of the world around them and avoid bumping into objects.” “We are only in the development stages, but once we have demonstrated that these rehabilitation techniques work, our long term goal is to see the treatment available on the NHS.”