(RxWiki News) Tremors in the upper limbs are a major concern for two-thirds of multiple sclerosis (MS) patients as they can contribute to disability and are considered by to be one of the most difficult symptoms to treat.
Botulinum toxin has been show to reduce tremors in MS patients, but not without side effects.
A recent study seeks to evaluate the safety and effectiveness of botulinum toxin type A MS for upper limb tremor.
The study was led by Anneke van der Walt, MD, consultant neurologist at The Royal Melbourne Hospital and research fellow with the University of Melbourne in Australia and published in the July issue of Neurology, the medical journal of the American Academy of Neurology.
Thirty-three upper limbs from 23 MS patients received either botulinum toxin type A or a placebo for three months. For the next three months, those that received the botulinum toxin were given the placebo and the placebo group was given the botulinum toxin.
"Discuss any concerns with your doctor before treating tremors."
Tremor severity and the ability to write and draw before, during and after receiving the treatments were measured. Video assessments from an independent rater were taken every six weeks for six months.
Results improved significantly more at six weeks and three months after the botulinum toxin than with the placebo.
Outcomes were scored on a ten point scale. Botulinum toxin participants improved an average of two points on tremor severity and an average of one point on writing and drawing.
“Tremor can present significant functional limitations for some persons with MS,” said Nancy D. Chiaravalloti, PhD, Director of Neuropsychology & Neuroscience Research at Kessler Foundation.
“Importantly, gains were noted on both standardized assessments of tremor and functional tasks (writing, drawing, pouring). This indicates a daily life benefit of the treatment, which is essential to the lives of persons with MS.”
Tremors are caused by damaged areas along the complex nerve pathways needed for coordination and movement.
Current treatment methods for MS tremors include medications, physical therapy and surgery, but evidence of benefit is conflicting and treatments like surgery can have serious side effects.
The use of botulinum toxin could solve current major treatment challenges. However, botulinum toxin is known to have its own side effects.
Botulinum toxin can lead to decrease in muscle spasticity and strength. In this study, mild to moderate reversible muscle weakness was observed in 42 percent of people after botulinum toxin treatment and six percent after placebo.
The study was funded by Box Hill MS Research Fund and the Royal Melbourne Hospital Neuroscience Foundation. Allergen, the pharmaceutical company that makes Botox, donated 40 vials of the product for the study.
All authors have reported conflicts of interest with pharmaceutical companies including Bayer, Bioden Idec, GlaxoSmithKline, Sanofi-Aventis, Merck Serono, Pfizer, Allergan, Boehringer Ingelheim and UBC Pharma.