Source: Cancer  |  Posted 9 years ago

By Ed Susman
Special to DG News
DENVER, CO -- April 18, 2002 -- Stroke patients who are left with spasticity in their upper limbs-a common sequela of stroke associated with long-term disability-can experience pain relief and improvement in mobility with injections of botulinum toxin, according to an open-label, multi-center American study.
A double-blind, multi-center study recently showed that one intramuscular injection of botulinum toxin type A (BTX-A: Botox, Allergan, Inc.) decreased muscle tone, improved functional disability, and was an affective treatment for post-stroke focal spasticity.
Researchers reported safety and efficacy outcomes of long-term use of botulinum toxin in 111 patients treated for stroke deficits, at the 54th Annual Meeting of the American Academy of Neurology (AAN).
Patients received up to three intramuscular injections of botulinum toxin, with a minimum of 12 weeks between treatments. A maximum of four treatment cycles across the double-blind and open-label trials was evaluated. Efficacy outcomes were assessed every six weeks for 52 weeks. All adverse events were recorded.
"In some of these cases, the patients are in a great deal of pain," said Dr. Mark Gordon, associate professor of clinical neurology at Albert Einstein College of Medicine, The Bronx, NY, "and we can usually relieve pain with the injections".
Botulinum toxin produced some relief of symptoms when injected into the flexor carpi radials, flexor carpi ulnaris, flexor digitorum profundus, flexor digitorum sublimis and/or the flexor pollicis longus muscles of the hand, forearm and wrist, Dr. Gordon reported.
"The improvement we see in these patients is not something that a normal person would consider as a major benefit. But in some of these patients, their arms are so fixed and frozen in position that they cannot even get the arm through the sleeve of a blouse or a robe. Sometimes, the robe or hospital gown is just thrown over the arm because it is so difficult to move. So if we are able to make those muscles relax enough so that a person can dress himself or herself or be dressed by a caretaker, that is a great quality of life improvement," said Catherine Turkel, Pharm D, director of clinical development at Allergan, and co-author of the study.
Injection with botulinum toxin also can relax clenched fists enough to allow the patient or caregivers to perform hygiene functions and can relieve pain associated with attempts to open the clenched fingers, Dr. Gordon said.
"We see this condition commonly among people who have had paralyzing strokes or strokes that have left arm muscles weakened," he said.
Results showed that 81 percent of patients achieved a one-point improvement in the Ashworth impairment scale (0-4 scale), 48 percent achieved a two-point improvement, and nine percent had a three-point improvement during the first three-month treatment cycle. Improvement in disability increased with longer treatment.
Some patients were able to maintain improvements with only one course of botulinum toxin injection - about 200 units to 240 units - although most patients required three or four injections over the 52-week treatment course.
Botulinum injections well tolerated; most adverse events were mild to moderate and were thought to be unrelated to the treatment.
The earlier double-blind study and this open-label study are part of Allergan?s application to the US Food and Drug Administration for approval of Botox for treatment of post-stroke spasticity, said Dr. Turkel.
"Especially for people with pain, this treatment seems to be reasonable. My concern is that people with profound disability due to stroke would seek this treatment in hopes of recovering greater function," said Dr. Ryan Uitti, associate professor of neurology at the Mayo Clinic, in Jacksonville, Florida.
Multiple intramuscular injections of botulinum toxin are safe and lead to sustained improvement in disability over a 52-week treatment course. The treatment, however, will not help recover function permanently lost by the initial consequences of the stroke, but is aimed at post-stroke complications caused by muscle spasms, Dr. Gordon concluded.
This study was supported by Allergan, Inc., in Irvine, California.