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Factors influencing response to Botulinum toxin type A in patients with idiopathic cervical dystonia: results from an international observational study.

Misra VP, Ehler E, Zakine B, Maisonobe P, Simonetta-Moreau M, INTEREST IN CD gro - BMJ Open (2012)

Bottom Line: The subjective duration of effect criterion was achieved by 49.3% of subjects; 28.6% of subjects achieved the responder definition.Factors most strongly associated with response were age (<40 years; OR 3.9, p<0.05) and absence of baseline head tremor (OR 1.5; not significant).Unrealistically high patient expectation and subjectivity may influence the perception of a quick waning of effect, but highlights that this aspect may be a hurdle to response in some patients.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurology, The National Hospital for Neurology & Neurosurgery, London, UK.

ABSTRACT

Objectives: Real-life data on response to Botulinum toxin A (BoNT-A) in cervical dystonia (CD) are sparse. An expert group of neurologists was convened with the overall aim of developing a definition of treatment response, which could be applied in a non-interventional study of BoNT-A-treated subjects with CD.

Design: International, multicentre, prospective, observational study of a single injection cycle of BoNT-A as part of normal clinical practice.

Setting: 38 centres across Australia, Belgium, Czech Republic, France, Germany, The Netherlands, Portugal, Russia and the UK.

Participants: 404 adult subjects with idiopathic CD. Most subjects were women, aged 41-60 years and had previously received BoNT-A.

Outcome measures: Patients were classified as responders if they met all the following four criteria: magnitude of effect (≥25% improvement Toronto Western Spasmodic Torticollis Rating Scale), duration of effect (≥12-week interval between the BoNT-A injection day and subject-reported waning of treatment effect), tolerability (absence of severe related adverse event) and subject's positive Clinical Global Improvement (CGI).

Results: High rates of response were observed for magnitude of effect (73.6%), tolerability (97.5%) and subject's clinical global improvement (69.8%). The subjective duration of effect criterion was achieved by 49.3% of subjects; 28.6% of subjects achieved the responder definition. Factors most strongly associated with response were age (<40 years; OR 3.9, p<0.05) and absence of baseline head tremor (OR 1.5; not significant).

Conclusions: Three of four criteria were met by most patients. The proposed multidimensional definition of response appears to be practical for routine practice. Unrealistically high patient expectation and subjectivity may influence the perception of a quick waning of effect, but highlights that this aspect may be a hurdle to response in some patients. CLINICAL REGISTRATION NUMBER: (NCT00833196; ClinicalTrials.gov).

No MeSH data available.


Related in: MedlinePlus

Subgroup analyses of responders (efficacy population). BoNT-A, Botulinum toxin A; CD, cervical dystonia; EMG, electromyography.
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fig2: Subgroup analyses of responders (efficacy population). BoNT-A, Botulinum toxin A; CD, cervical dystonia; EMG, electromyography.

Mentions: Analysis of the response criteria by subgroup is shown in figure 2 and showed that there were variations in response, albeit these results were not statistically significant. Data revealed that more subjects responded among subgroups presenting with laterocollis (41.7% vs 26.7% with rotation), without baseline tremor (33.2% vs 23.7% with tremor), and those not receiving concomitant medication at baseline (35.1% vs 22.8% receiving baseline concomitant medications).


Factors influencing response to Botulinum toxin type A in patients with idiopathic cervical dystonia: results from an international observational study.

Misra VP, Ehler E, Zakine B, Maisonobe P, Simonetta-Moreau M, INTEREST IN CD gro - BMJ Open (2012)

Subgroup analyses of responders (efficacy population). BoNT-A, Botulinum toxin A; CD, cervical dystonia; EMG, electromyography.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC3378940&req=5

fig2: Subgroup analyses of responders (efficacy population). BoNT-A, Botulinum toxin A; CD, cervical dystonia; EMG, electromyography.
Mentions: Analysis of the response criteria by subgroup is shown in figure 2 and showed that there were variations in response, albeit these results were not statistically significant. Data revealed that more subjects responded among subgroups presenting with laterocollis (41.7% vs 26.7% with rotation), without baseline tremor (33.2% vs 23.7% with tremor), and those not receiving concomitant medication at baseline (35.1% vs 22.8% receiving baseline concomitant medications).

Bottom Line: The subjective duration of effect criterion was achieved by 49.3% of subjects; 28.6% of subjects achieved the responder definition.Factors most strongly associated with response were age (<40 years; OR 3.9, p<0.05) and absence of baseline head tremor (OR 1.5; not significant).Unrealistically high patient expectation and subjectivity may influence the perception of a quick waning of effect, but highlights that this aspect may be a hurdle to response in some patients.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurology, The National Hospital for Neurology & Neurosurgery, London, UK.

ABSTRACT

Objectives: Real-life data on response to Botulinum toxin A (BoNT-A) in cervical dystonia (CD) are sparse. An expert group of neurologists was convened with the overall aim of developing a definition of treatment response, which could be applied in a non-interventional study of BoNT-A-treated subjects with CD.

Design: International, multicentre, prospective, observational study of a single injection cycle of BoNT-A as part of normal clinical practice.

Setting: 38 centres across Australia, Belgium, Czech Republic, France, Germany, The Netherlands, Portugal, Russia and the UK.

Participants: 404 adult subjects with idiopathic CD. Most subjects were women, aged 41-60 years and had previously received BoNT-A.

Outcome measures: Patients were classified as responders if they met all the following four criteria: magnitude of effect (≥25% improvement Toronto Western Spasmodic Torticollis Rating Scale), duration of effect (≥12-week interval between the BoNT-A injection day and subject-reported waning of treatment effect), tolerability (absence of severe related adverse event) and subject's positive Clinical Global Improvement (CGI).

Results: High rates of response were observed for magnitude of effect (73.6%), tolerability (97.5%) and subject's clinical global improvement (69.8%). The subjective duration of effect criterion was achieved by 49.3% of subjects; 28.6% of subjects achieved the responder definition. Factors most strongly associated with response were age (<40 years; OR 3.9, p<0.05) and absence of baseline head tremor (OR 1.5; not significant).

Conclusions: Three of four criteria were met by most patients. The proposed multidimensional definition of response appears to be practical for routine practice. Unrealistically high patient expectation and subjectivity may influence the perception of a quick waning of effect, but highlights that this aspect may be a hurdle to response in some patients. CLINICAL REGISTRATION NUMBER: (NCT00833196; ClinicalTrials.gov).

No MeSH data available.


Related in: MedlinePlus