Clown-care reduces pain in children with cerebral palsy undergoing recurrent botulinum toxin injections- A quasi-randomized controlled crossover study

PLoS One. 2017 Apr 17;12(4):e0175028. doi: 10.1371/journal.pone.0175028. eCollection 2017.


Objective: We investigated the impact of clown-care on pain in 45 children with cerebral palsy who underwent recurrent Botulinum-toxin injections (age 7.04± 4.68 years). Participants were randomized to receive either clown (n = 20) or standard (n = 25) -care.

Methods: Pain Visual-Analogue-Scale (range 1-5) was reported before and after procedures. Pain assessment was lower for children undergoing Botulinum-toxin injections with clown-care (2.89± 1.36) compared to standard-care (3.85± 1.39; p = 0.036) even though pain anticipated prior to procedures was similar (~3).

Findings: Children who underwent the first procedure with clown-care reported lower pain even after they crossed-over to the following procedure which was standard (p = 0.048). Carryover effect was more prominent in injection-naïve children (p = 0.019) and during multiple procedures (p = 0.009). Prior pain experience correlated with pain in subsequent procedures only when first experience was standard-care (p = 0.001).

Conclusions: Clown-care alleviated pain sensation during Botulinum-toxin injections and initial clown-care experience reduced pain during subsequent injections even though clowns were not present.

Trial registration: ID # NCT01377883.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial

MeSH terms

  • Adolescent
  • Botulinum Toxins / administration & dosage*
  • Cerebral Palsy / drug therapy
  • Cerebral Palsy / physiopathology
  • Cerebral Palsy / therapy*
  • Child
  • Child, Preschool
  • Cross-Over Studies
  • Female
  • Humans
  • Infant
  • Injections, Intramuscular
  • Israel
  • Laughter Therapy / methods*
  • Male
  • Muscle Hypertonia / drug therapy
  • Muscle Hypertonia / physiopathology
  • Neuromuscular Agents / administration & dosage
  • Pain / physiopathology
  • Pain / prevention & control*
  • Pain Management / methods*
  • Pain Measurement
  • Treatment Outcome


  • Neuromuscular Agents
  • Botulinum Toxins

Associated data


Grant support

Shaare Zedek Medical Center partially covered study expenses (HB, AC, YS, RLO). The second phase of this study (crossover) was funded by the Magi Foundation (HB 19003249),,namef&view=. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Biostatistical Consulting (owned by the author LD) provided support in the form of salary for author LD but did not have any additional role in the study design, data collection, decision to publish, or preparation of the manuscript. The specific role of this author is articulated in the ‘author contributions’ section.