LONDON, England (CNN) -- Anyone who has suffered and survived a stroke will know of its devastating consequences and will be painfully aware that the road back to a normal life is a long and frustrating journey.
A patient views himself on an LCD screen and plays Hadasit's "catch me if you can" VR system game during trials which are helping patients regain movement and combat chronic pain.
But new virtual reality rehabilitation therapies, which are currently undergoing trials, are helping stroke sufferers in their fight to regain their movement and gradually rediscover their independence.
According to the World Health Organization 15 million people around the world suffer a stroke each year, with five million of those resulting in death and a further five million left with a permanent disability.
In the U.S. a person dies of a stroke every three minutes and in the UK stroke is the biggest single cause of major disability and is the third most common cause of death.
Put simply a stroke is a heart attack of the brain. Medical practitioners used to call a stroke an apoplexy -- derived from the Greek word for seizure, "apoplexia" -- because of the way it strikes people down.
Generally speaking there are two types of stroke -- those caused by blood clots in the brain and those that occur when blood vessels burst. In both instances, the brain is starved of oxygen, which leads to the damage of vital cells.
People who survive a stroke are often left with varying degrees of disability which include paralysis, confusion, loss of vision and/or speech and difficulty walking or performing basic everyday tasks.
Earlier this month, Israeli company Hadasit -- the technology transfer company of Hadassah Medical Organization -- began its Phase II Study of their Virtual Reality (VR) system for the treatment of chronic pain and stroke rehabilitation at the Hadassah University Hospital in Jerusalem.
The system is a product of multidisciplinary work in the Department of Physical Medicine and Rehabilitation at Hadassah Mount Scopus Hospital.
Shimon Shiri, a rehabilitation psychologist at Hadassah and an inventor of the VR system, told CNN how the project began.
"We were faced with more and more patients with chronic pain," Shiri said, "who seemed to suffer in spite of pain-killers and surgery. We realized that these patients may have experienced a learning process where pain was imprinted or 'burned' into their nervous systems."
Hadasit's Marjie Hadad told CNN: "We were aware of a growing body of neuropsychological evidence suggesting two major processes. Firstly, the brain undergoes changes following chronic pain and secondly, that brain plasticity is substantial." (Brain plasticity is the lifelong ability of the brain to reorganize neural pathways).
"We found virtual reality to be a realm that allows the transfer of information directly to the brain, switching the previous pathological learning to adaptive learning," Hadad said.
Dr Uri Feintuch, a computational neuroscientist at the Hadassah School of Occupational Therapy explains how the VR system is set up. "We chose not to use a Head Mounted Display (HMD) as we generally prefer not to put any cumbersome gear on patients who have suffered a stroke. After initially using a projection system we concluded that a large flat screen would do."
Patients view themselves in real time on an LCD screen and use a mouse or joystick. Small movements of the mouse by the patient create large virtual movements of the patients arm, hand or shoulder on the screen.
A video camera photographs patients and a computer simulates the functions based on the physical presence of each patient at that moment.
"The patient sees himself moving his arm, even though he really is not," explains Shiri. "The virtual experience activates the mirror neurons and induces a therapeutic effect on the brain that reduces pain and increases function. By viewing the movement of the arm without pain, the brain undergoes a corrective learning process."
So far, only a few patients have completed the trial but preliminary results have shown improvement in several areas notably significant decrease in pain and the fear of pain, increased arm functioning and an improved physical and emotional state of the patients.
The Phase II Study will be using a much improved prototype system and patients will be randomly assigned to either a VR or a control group. Clinicians will also be blind to the treatment type that the patient has received.
Hadad told CNN: "Once the system's efficacy is proven clinically in the randomized controlled trial, and the system has been approved by the appropriate regulatory bodies, we hope to offer it as a therapeutic tool for post-stroke patients."
Hadasit are also testing another system which hopes to treat tension headaches and migraines.
In April 2007, UK researchers at the University of Ulster announced the results of a pilot study which also used a VR system to help stroke patients regain use of their upper limbs.
Patients were immersed in a virtual world using a HMD with their hand placed into a flexible glove that was fitted with positional and orientation sensors. Additional sensors were attached to the patient's shoulder.
The sensors allow the patients hand and arm movements to be tracked in the virtual environment and provide the patient with visual feedback.
The environments simulated simple scenarios in the home or on the high street enabling patients to practice moving their limbs again and relearn simple tasks like eating and drinking.
Patients also received audio feedback from a virtual physiotherapist who offered encouragement during the tasks.
Study leader, Jacqueline Crosbie from the University of Ulster's School of Rehabilitation Science said: "Different virtual worlds provide rich environments to relieve the boredom of practicing what can often be repetitive and frustrating tasks."
"The system can also be configured to exaggerate small movements, increasing the feeling of achievement and improving patient motivation."
The project is unique to the UK and Ireland and Crosbie is optimistic that this form of rehabilitation therapy will considerably improve the quality of life for people living with the effects of a stroke.
It is hoped that in the future that some patients, once they are trained, will be to practice upper limb movements independently, allowing for a swifter and fuller recovery.
How to reduce your chances of suffering a stroke:
Source: www.stroke.org.uk E-mail to a friend