August 7, 2002
Toxin Injections Prove Useful For Spasticity After Stroke
INDIANAPOLIS - Researchers are offering new hope for stroke patients
suffering from spasticity of the hand with a drug that has proven effective
in relieving muscle tightness or twitching in other areas of the body,
according to an article in the Aug. 8 issue of the New
England Journal of Medicine.
The report indicates that botulinum toxin type A, also known as Botox®,
reduces disability caused by spasticity of the wrist and finger muscles
in patients who have had a stroke. This is the first placebo-controlled,
multi-center trial to assess the benefit of one-time injections of botulinum
toxin type A.
Allison Brashear, M.D., principal investigator and first author of the
article, said the results demonstrate a useful treatment for patients
with functional disabilities from stroke.
"This is the first large trial to show that botulinum toxin type
A improved function and muscle tone following a stroke," said Dr.
Brashear, associate professor of neurology at the Indiana University School
of Medicine. "A number of studies have demonstrated that botulinum
toxin type A decreases muscle rigidity in spastic muscles and one small
study has shown functional improvement from this therapy. However, use
of the therapy has become common practice so the point of this clinical
trial was to assess the effects of one-time treatment on a large, controlled
group."
Stroke affects approximately 600 out of every 100,000 people in the United
States, with nearly 70 percent of patients surviving the stroke. The prevalence
of disabilities associated with stroke, including arm and hand spasticity,
is high. Spasticity in upper limbs is especially debilitating because
it can interfere with many daily activities, including personal hygiene
and dressing.
Nineteen medical institutions were involved over the two-year period
of the study. All of the 126 volunteers enrolled in the 12-week study
had some degree of spasticity in their wrist or fingers after a stroke.
The volunteers were randomized to either a placebo group or a group receiving
one-time injections of 200 to 240 units of botulinum toxin type A.
The volunteers were asked to select one of four areas of disability as
the principal target of treatment. That area was rated as moderate to
severe on a four-point scale for determining degree of disability. The
areas targeted for treatment by the patient pertained to perceived disability
caused by the spasticity. They were personal hygiene, dressing, pain or
limb position - all of which can be affected by a spastic or "frozen"
limb. The rating was done at the initiation of the trial and at six weeks,
at which time 40 of the 64 participants in the botulinum toxin type A
group reported improvement in the selected area of disability. In the
placebo group only 17 of the 62 participants reported improvement.
Significant improvement in wrist and finger flexors was observed in the
majority of patients one week after the injection. The improvement was
sustained at the 12-week follow-up. Participants also showed no adverse
reactions to the botulinum toxin type A injections.
Following the conclusion of their participation in the clinical trial,
111 of the 126 participants volunteered to receive up to three additional
treatments and each set of injections had positive effects that lasted
for at least 12 weeks and, in some cases, as long as 18 to 24 weeks, the
study reports.
"The findings suggest that botulinum toxin is useful in improving
muscle tone, function and quality of life in patients with wrist and finger
spasticity
after a stroke," Dr. Brashear concludes.
Allergan, maker of Botox, supported the clinical trial.
In 1989, Botox therapy was approved by the U.S. Food and Drug Administration
for the treatment of strabismus (crossed eyes) and blepharospasm (uncontrollable
blinking). In December 2000, the FDA approved Botox for the treatment
of abnormal head position and neck pain associated with cervical dystonia,
a movement disorder characterized by involuntary muscle contractions.
This past April, the FDA approved Botox® Cosmetic, botulinum toxin
type A, for the temporary improvement in the appearance of moderate to
severe forehead wrinkles in adult men and women age 65 or younger.
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Media Contact: Mary Hardin
317-274-7722
mhardin@iupui.edu
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