New research shows that repeated treatments of botulinum toxin type A (BoNTA) over one year after a stroke can improve muscle tone and reduce pain in the arms and hands, making it easier for patients to dress themselves and perform personal hygiene.
"The treatment resulted in sustained and meaningful functional improvement that makes a difference in the daily lives of stroke patients and the people who care for them," said Allison Brashear, M.D., professor and chairman of neurology at Wake Forest University Baptist Medical Center.
The findings were presented today at the 2005 Annual Meeting of the American Association of Physical Medicine and Rehabilitation (AAPM&R) in Philadelphia. The study was conducted by Brashear and colleagues while she was at Indiana University School of Medicine.
This was the first long-term study to evaluate repeated treatment with BoNTA for post-stroke spasticity, a muscle tightness that inhibits movement. Brashear and colleagues had previously reported (New England Journal of Medicine, August 2002) that one-time injections of BoNTA are safe and effective in people with wrist and finger spasticity after a stroke.
The study reported on today involved 35 centers and included 279 stroke patients with wrist, hand or elbow spasticity. Disabling spasticity affects between 17 percent and 30 percent of stroke survivors and can lead to functional limitations, discomfort and pain. Upper limb spasticity can interfere with patients' mobility, comfort and their ability to dress, wash or feed themselves and perform other activities of daily living.
During the year-long study, all study participants received up to five treatments with BoNTA, which is sold under the trade name BOTOX®. For the study, the BoNTA injections were given at the wrist, thumbs, fingers and elbows to block overactive nerve impulses that trigger excessive muscle contractions.
Researchers found that at week six of the study, muscle tone in the wrist, fingers, thumb, and elbow was markedly improved from baseline, and was sustained throughout the study. The study also measured functional disability in four areas: hygiene, dressing, limb posture and pain. Before the first treatment, patients selected an area that was most important to them. On a four-point scale that ranged from "no disability" to "severe disability," at least 50 percent of patients achieved a 1-point or greater improvement in the area they targeted.
"If it isn't managed effectively, post-stroke spasticity can result in very disabling complications such as contractures, a condition that leaves the muscles and tendons permanently shortened," said Brashear. "Early intervention with effective therapies is absolutely vital to prevent the profound disability that afflicts many stroke patients, and to lessen the emotional and financial toll on caregivers and the health care system as a whole."
The study found that adverse events related to treatment, such as headache, pain in the arm, or an influenza-like illness, were reported in 7 percent of patients. Brashear said these results show that the treatment is safe and well-tolerated in post-stroke patients and may represent a significant advantage over many oral anti-spasticity medications.
"Such drugs are associated with a high incidence of systemic effects such as sedation, mental confusion, dizziness and muscle weakness, all of which can seriously hinder rehabilitation after a stroke," she said.
Every year, about 700,000 Americans suffer a new or recurring stroke. Stroke is a leading cause of serious, long-term disability in the United States, and it is estimated that the costs associated with lost productivity due to stroke-related disability will total $21.8 billion in 2005.
The research was funded by Allergan Inc., the pharmaceutical company that developed BoNTA. Brashear's co-researchers were Elie Elovic, M.D., of Kessler Medical Rehabilitation Research and Education Corporation and New Jersey Medical School, Darryl Kaelin, M.D., of the Shepherd Center, Atlanta, and Robin McIntosh, Jingyu Liu, Ph.D., and Catherine Turkel, PharmD., M.B.A., all with Allergan Inc.