***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Objective To describe the health-related quality of life ( HRQOL ) burden of cervical dystonia ( CD ) and report on the HRQOL and patient perception of treatment benefits of abobotulinumtoxinA ( Dysport ) . Design The safety and efficacy of a single injection of abobotulinumtoxinA for CD treatment were evaluated in a previously reported international , multicenter , double-blind , r and omised trial . HRQOL measures were assessed in the trial and have not been previously reported . Setting Movement disorder clinics in the USA and Russia . Participants Patients had to have a diagnosis of CD with symptoms for at least 18 months , as well as a total Toronto Western Spasmodic Torticollis Rating Scale ( TWSTRS ) score of at least 30 ; a Severity domain score of at least 15 ; and a Disability domain score of at least 3 . Key exclusion criteria included treatment with botulinum toxin type A ( BoNT-A ) or botulinum toxin type B ( BoNT-B ) within 16 weeks of enrolment . Interventions Patients were r and omised to receive either 500 U abobotulinumtoxinA ( n=55 ) or placebo ( n=61 ) . Primary and secondary outcome measures Efficacy assessment s included TWSTRS total ( primary end point ) and subscale scores at weeks 0 , 4 , 8 , 12 ; a pain visual analogue scale at weeks 0 and 4 ; and HRQOL assessed by the SF-36 Health Survey ( SF-36 ; secondary end point ) at weeks 0 and 8 . Results Patients with CD reported significantly greater impairment for all SF-36 domains relative to US norms . Patients treated with abobotulinumtoxinA reported significantly greater improvements in Physical Functioning , Role Physical , Bodily Pain , General Health and Role Emotional domains than placebo patients ( p≤0.03 for all ) . The TWSTRS was significantly correlated with Physical Functioning , Role Physical and Bodily Pain scores , for those on active treatment . Conclusions CD has a marked impact on HRQOL . Treatment with a single abobotulinumtoxinA injection results in significant improvement in patients ’ HRQOL . Trial registration number The trial is registered at Clinical Trials.gov , numbers NCT00257660 and NCT00288509 The aim of this study was to evaluate the efficacy and safety of intramuscular ( IM ) administration of botulinum toxin type A ( Dysport((R ) ) , Ipsen Biopharm Ltd. ) for the treatment of cervical dystonia ( CD ) and the long-term safety and efficacy of repeated treatments . During the r and omized , double-blind , placebo-controlled phase patients were r and omized to 500 units Dysport  ( n = 55 ) or placebo ( n = 61 ) . Efficacy assessment s included the Toronto Western Spasmodic Torticollis Rating Scale ( TWSTRS ) total and subscale scores , visual analogue scale ( VAS ) for pain , subject/investigator 's VAS for symptom assessment s. Patients completing the double-blind treatment could enter an open-label extension phase and receive up to 4 additional Dysport treatments . Dysport produced a significant decrease from baseline in mean ( + /-SE ) TWSTRS total scores compared with placebo at Week 4 ( primary efficacy endpoint ; -15.6 + /- 2.0 vs. -6.7 + /- 2.0 ; p < 0.001 ) with significant improvements sustained to Week 12 ( p = 0.019 ) . Dysport also produced significant improvements in TWSTRS subscale scores , VAS pain scores , and subject/investigator 's VAS symptom assessment s compared to placebo . The mean duration of open-label study participation was 51.9 weeks ( range 3.9 - 94.0 weeks ) . During open-label treatment , all treatment cycles result ed in improvements in mean TWSTRS total and subscale scores at Week 4 post-treatment ; greatest improvement was seen in cycle 1 . The mean duration between treatment cycles was 15 - 17 weeks . Dysport demonstrated a good long-term safety profile ; most adverse events were mild or moderate and typical of the known safety profile of Dysport in this indication . These results confirm that Dysport ( 500 units ) is safe , effective , and well-tolerated in patients with CD We used turns-amplitude analysis of the EMG as a guidance for botulinum toxin ( BT ) treatment in 19 patients with cervical dystonia . At the first examination , muscles showing abnormal activity ( > 100 turns/sec at rest ) were given BT 75 units ( 10 patients ) or placebo ( 9 patients ) . At subsequent examinations , about 6 , 12 and 18 weeks after the start , BT 75 units were given to all hyperactive muscles . Six weeks after the first BT treatment the sternocleidomastoid muscle contralateral to the involuntary head rotation and the ipsilateral and contralateral posterior neck muscles ( PNM ) showed a reduction of involuntary activity , as indicated by reduced turns/sec and mean amplitude at rest . Similar changes were seen when comparing BT treatment with placebo . The reduction was greater in the contralateral sternocleidomastoid muscle than in PNM , suggesting that PNM need higher doses of BT . At maximal voluntary contraction , BT treated muscles showed unchanged turns/sec ( 5/6 tests ) , decreased mean amplitude and increased ratio ( turns/amplitude ) . This may reflect a functional r and om loss of muscle fibres , combined with inability to activate all motor units . A high ( 89 % ) clinical success rate with BT therapy was obtained , and it is concluded that quantitative EMG is a useful tool for the precise identification of hyperactive muscles , for optimal placing of the injection cannula and for unbiased monitoring of the treatment effect OBJECTIVE IncobotulinumtoxinA differs from available formulations in that it does not have accessory proteins . IncobotulinumtoxinA has previously shown non-inferiority to onabotulinumtoxinA for the treatment of CD with a 1:1 dosing regimen . The objective of this study was to compare the safety and efficacy of incobotulinumtoxinA ( 120 U , 240 U ; Merz Pharmaceuticals ) to placebo in subjects with cervical dystonia ( CD ) . METHODS This was a prospect i ve , double-blind , r and omized , placebo-controlled , multicenter clinical trial in  botulinum toxin-treated or toxin-naïve CD patients . The primary outcome measure was change from baseline to Week 4 on the Toronto Western Spasmodic Torticollis Rating Scale ( TWSTRS ) Total score . Adverse events ( AEs ) also were evaluated . RESULTS Participants ( N=233 ) were mostly women ( 66 % ) , a mean of 52.8 years old , who had CD for a mean of 51.9 months . Of those , 39 % were toxin-naïve . IncobotulinumtoxinA significantly improved TWSTRS-Total scores from baseline to Week 4 compared to placebo ( placebo=-2.2 ; 120 U=-9.9 , and 240 U=-10.9 ; 240 U vs. placebo p<0.001 and 120 U vs. placebo p<0.001 ) . This effect persisted through to the end of the study . The most frequently reported AEs in the incobotulinumtoxinA groups were dysphagia , neck pain , and muscular weakness which were generally mild . INTERPRETATION IncobotulinumtoxinA ( at doses of 120 U or 240 U ) is a safe and effective treatment for CD in previously-treated as well as toxin-naïve subjects We studied the effect of botulinum toxin injection in 30 patients with torticollis in a double-blind , placebo-controlled , crossover study . A fixed dose of toxin was injected into the contralateral sternocleidomastoid and both trapezius muscles . Clinical improvement was assessed by a rating scale and by patient self-evaluation . Subjective rating noted improvement in some patients , but there was no change in objective measures . The use of larger doses and injection of additional muscles may be necessary to achieve increased efficacy of botulinum toxin in the treatment of torticollis Background To determine whether botulinum toxin treatment history affected the outcomes of a study comparing the safety and efficacy of incobotulinumtoxinA with placebo in subjects with cervical dystonia ( CD ) . Methods This was a prospect i ve , double-blind , r and omized , placebo-controlled , multicenter trial in  botulinum toxin-treated or toxin-naïve CD subjects . Subjects received a fixed dose of either 120 U or 240 U of incobotulinumtoxinA or placebo . The primary outcome measure was change from baseline to Week 4 in the Toronto Western Spasmodic Torticollis Rating Scale ( TWSTRS ) total score . Treatment-emergent adverse events ( TEAEs ) were also evaluated . This report represents a subgroup analysis of botulinum toxin-treated or toxin-naïve subjects . Results Participants ( N = 233 ; 38.6 % toxin-naïve ) had a mean age of 52.8 years . IncobotulinumtoxinA significantly improved TWSTRS total scores from baseline to Week 4 in both dose groups versus placebo , and the improvement persisted through the end of the study ( ≤20 weeks ) . Both the previously toxin-treated and toxin-naïve subjects demonstrated significant improvements in TWSTRS total scores at Week 4 compared to baseline . The most frequent TEAEs in the incobotulinumtoxinA groups were dysphagia , neck pain , and muscular weakness , which were generally mild . TEAEs were more common in the 240 U group and toxin-naïve subjects . Discussion Overall , incobotulinumtoxinA was safe and effective in CD , regardless of toxin therapy history . A lower starting dose may be better tolerated among toxin-naïve subjects without sacrificing efficacy BACKGROUND Approved botulinum toxin A products require reconstitution . AbobotulinumtoxinA solution for injection is a ready-to-use liquid formulation of abobotulinumtoxinA. OBJECTIVES The objective of this study was to demonstrate the superior efficacy of abobotulinumtoxinA solution for injection to placebo and to test the noninferior efficacy of abobotulinumtoxinA solution for injection versus abobotulinumtoxinA ( dry formulation ) in cervical dystonia . METHODS This was a phase-3 , multicenter , prospect i ve , double-blind , r and omized , active , and placebo-controlled study ( N = 369 ) . Patients with cervical dystonia were r and omized ( 3:3:1 ) to abobotulinumtoxinA solution for injection 500 U , abobotulinumtoxinA 500 U , or placebo . Following the double-blind phase , patients received abobotulinumtoxinA solution for injection , open-label , for up to 4 cycles . The primary outcome was change from baseline at week 4 of the Toronto Western Spasmodic Torticollis Rating Scale total score . Secondary measures included change from baseline or cycle baseline in Toronto Western Spasmodic Torticollis Rating Scale scores . RESULTS At week 4 , both products were superior to placebo ( Toronto Western Spasmodic Torticollis Rating Scale total score least square mean decrease from baseline , abobotulinumtoxinA solution for injection 500 U -12.5 , abobotulinumtoxinA 500 U -14.0 , placebo -3.9 ; P < .0001 vs placebo ) . The noninferiority limit of 3 points in the Toronto Western Spasmodic Torticollis Rating Scale total score at week 4 was not met for abobotulinumtoxinA solution for injection versus abobotulinumtoxinA.  Toronto Western Spasmodic Torticollis Rating Scale total score reductions were maintained for up to 4 cycles of abobotulinumtoxinA solution for injection open-label follow-up treatment . Safety profiles of abobotulinumtoxinA solution for injection and abobotulinumtoxinA were similar , with dysphagia and injection-site pain the most frequent drug-related adverse events . CONCLUSIONS Although the predefined noninferiority criterion was not met , abobotulinumtoxinA solution for injection was similarly effective to freeze-dried abobotulinumtoxinA in reducing Toronto Western Spasmodic Torticollis Rating Scale total scores with a similar safety profile . AbobotulinumtoxinA solution for injection efficacy was maintained with chronic open-label treatment , and this novel formulation may add convenience as well as dosing accuracy to treatment with abobotulinumtoxinA. © 2016 International Parkinson and Movement Disorder Society Typically , botulinum toxin injections for blepharospasm or cervical dystonia ( CD ) are administered at approximately 3-month intervals , reflecting concerns that shorter intervals might increase the risk of adverse events ( AEs ) and development of neutralizing antibodies . These post-hoc analyses investigated flexible incobotulinumtoxinA ( Xeomin ® ) injection intervals ( 6 - 20 weeks ) in patients with blepharospasm or CD . Patients received 
    Output:
    
The primary efficacy outcome was improvement in cervical dystonia-specific impairment .
The primary safety outcome was the proportion of participants with any adverse event .
Treatment with BtA was associated with a decreased risk of participants withdrawing from trials .
We have moderate certainty in the evidence across all of the aforementioned outcomes .We found no evidence supporting the existence of a clear dose-response relationship with BtA , nor a difference between BtA formulations , nor a difference with use of EMG-guided injection .
We have moderate certainty in the evidence that a single BtA treatment session is associated with a significant and clinical ly relevant reduction of cervical dystonia-specific impairment , including severity , disability , and pain , and that it is well tolerated , when compared with placebo .
There is also moderate certainty in the evidence that people treated with BtA are at an increased risk of developing adverse events , most notably dysphagia and diffuse weakness .
There is no evidence from RCTs to allow us to draw definitive conclusions on the optimal treatment intervals and doses , usefulness of guidance techniques for injection , the impact on quality of life , or the duration of treatment effect