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By Ed Susman, Contributing Writer, MedPage Today Note that this study was published as an abstract and presented at a conference. These data and conclusions should be considered to be preliminary until published in a peer-reviewed journal.Note that this small case-series demonstrated no significant functional improvements in symptoms of hereditary spastic paraparesis after treatment with botulinum toxin.Be aware that due to the small sample size, power to detect clinically meaningful improvements was limited.SYDNEY -- Despite success in treatment of other movement disorders, botulinum toxin type A failed to make much difference in outcomes of individuals diagnosed with rare hereditary spastic paraplegia, researchers said here.
"Although spasticity, strength, and the Ashworth scales all showed some degree of improvement, none achieved statistically significant differences," Helio Teive, MD, PhD, of the Federal University of Parana in Curitiba, Brazil, and his team reported at the annual International Conference on Parkinson's Disease and Movement Disorders.
They presented results of treatment for 11 patients with pure hereditary spastic paraplegia -- seven of whom were women. The average age of the patients was 41.5 and they had been diagnosed with the disorder for 23.5 years on average.
The patients were included in the study if they exhibited significant spasticity and functional interference with walking abilities. Significant lower limb weakness was considered as exclusion criteria, the researchers reported. They originally tested 29 patients, but only 11 fit the criteria for hereditary spastic paraplegia.
Before therapy and 30 days after treatment with botulinum toxin the patients underwent a battery of standardized assessments: the modified Ashworth scale, the scale for lower limb adductor spasticity, assessment of lower limb weakness, the 10-meter walk test, the modified Borg scale for subjective perception of fatigue, the Hereditary Spastic Paraplegia scale, and the functional independence measure.
The patients were also queried about their subjective improvement in gait performance. Teive reported that 10 of the 11 patients reported improvements in posture and gait performance.
"Our findings suggest that the improvements provided by botulinum toxin type A injections for the treatment of lower limb spasticity are mainly subjective and not mirrored by small improvements in more objective measures of spasticity and functionality," the researchers wrote.
"Hereditary spastic paraplegia is a very rare disease," Witsanu Kumthronthip, MD, a neurorehabilitation specialist at Mahidol University Medical School in Bangkok, told MedPage Today. "I have used botulinum toxin in treating a patient with this disease and my outcomes were very much in line with what this study from Brazil found. The improvements we saw were minor and did not appear to be greatly beneficial to the patient."
Kumthronthip, who reviewed the poster presentation, said, "The problem with this disease is that there are two major aspects, spasticity which can be improved with botulinum toxin and generalized lower body weakness, which is not helped by the toxin injections. Hence the overall improvement is minimal."
He added, "I use botulinum toxin extensively in my practice for movement disorders and in general it works very well. But there are always some conditions that are not amenable to botulinum therapy."
Irving Asher, MD, professor of neurology at the University of Missouri at Columbia, told MedPage Today, "We use botulinum toxin for treating all kinds of disorders including dystonia and various forms of spasticity. I am surprised that it is not effective in the area of hereditary spastic paraplegia."
Teive and colleagues listed no disclosures.
Kumthronthip had no disclosures.
Asher reported commercial relationships with Merz and Teva.
Primary source: Movement Disorders Society
Source reference:
Nickel R et al, "Type A botulinun toxin for the treatment of hereditary spastic paraparesis -- Results in 11 cases" MDS 2013.
