The American Stroke Association likens biofeedback to looking in a mirror to check that one is moving in the correct way. Electrodes measure bodily functions – heart rate, muscle movements or blood pressure – and the information is fed back to the patient. Biofeedback is mainly used in stress-related conditions, demonstrating to patients how relaxation improves symptoms. Its effectiveness after a stroke is disputed and still experimental. However, there is growing interest in using biofeedback in stroke rehabilitation therapy.
How It Works
Biofeedback takes three forms. Thermal biofeedback measures skin temperature. Neurofeedback measures brain activity and electromyography (EMG) measures muscle activity. Measurements captured by the electrodes are displayed on a monitor. A therapist explains this data to the patient. Initially by trial and error, the patient alters his behavior and the resultant readings are displayed on a screen. These changing readings provide visible evidence of how a patient's reactions are influencing his symptoms or improving his bodily functions. In time patients learn to control their symptoms without needing the monitor.
General Benefits
Biofeedback is a drug-free therapy. It is a treatment that gives patients a sense of control over their own illness and recovery. Visible evidence of improvement is a psychological encouragement. It has the most value in conditions where there is a psychological element rather than a purely physical cause. For this reason biofeedback is more commonly used in patients with incontinence, insomnia, migraine, fibromyalgia, high blood pressure or anxiety.
Specific Potential Benefits for Stroke
Biofeedback has demonstrable value in reducing high blood pressure. Muscle function data is potentially useful since stroke patients have frequently lost the use – or have reduced use – of a limb. EMG feedback is used with physiotherapy to help patients reeducate their limbs in movement. It can also help teach patients how to grip and then release objects in a stroke-impaired hand. A 2009 article in the Biofeedback Matters newsletter suggested that while physiotherapy alone could improve grip, teaching stroke patients to relax and release objects was harder. Stroke patients' brains and muscles can be overactive, causing continued muscle tension when a patient desires to release an object. Biofeedback could help because of its proven benefit in teaching relaxation. According to Dr. Richard Harvey of Chicago's Rehabilitation Institute, biofeedback usefully teaches improved motor control, but it cannot help patients learn new functional tasks.
Research
Early research was promising. A 1989 study at the Stroke Research Unit, Nottingham UK found stroke patients receiving EMG biofeedback regained more arm function than patients who did not. Patients with more extreme impairment showed the most benefit. In 1994, a stroke rehabilitation center in Rome, Italy, showed similar benefits in biofeedback improving leg strength. Unfortunately, many of the studies demonstrating benefits for stroke patients have been criticized for their small sample size and imprecise terminology. As head of Rehabilitation at St. Joseph's Health Care, London, Ontario, Dr. Robert Teasell reviewed studies performed between the 1960s and 2003. Teasell found that biofeedback did appear more effective than conventional therapies but that larger studies are needed to confirm these results. In 2006, the American Stroke Association updated this information by commenting that in the intervening years since Teasell's review, essential research into biofeedback and stroke still had not occurred.
References
- University of Maryland Medical Center: Biofeedback
- Complimentary Healthcare Information Service; Biofeedback; L. Van Someren; 2005
- Biofeedback Resources International; Biofeedback Matters Newsletter; June 2009
- Stroke Research Unit, Nottingham UK:The Effectiveness of EMG Biofeedback in the Treatment of Arm Function After Stroke; J. Crow; N. Lincoln, F. Nouri and W. De Weerdt; December 1989
- Stroke Magazine; Rehabilitation of Walking With Electromyographic Biofeedback in Foot-Drop After Stroke, D. Intiso, V. Santilli, M. Grasso, R. Rossi and I. Caruso; 1994
- Journal of the Royal Society of Medicine; Biofeedback Therapy in Stroke Rehabilitation: A Review; M. Glanz, S. Klawansky and T. Chalmers; January 1997
- “Stroke Connection Magazine”; A Rehab Revolution; Emily Springer; September/October 2004
- American Stroke Association: Biofeedback
