Therapies for children with cerebral palsy: A Web of Science-based literature analysis.

OBJECTIVE: To identify global research trends in three therapies for children with cerebral palsy. DATA RETRIEVAL: We performed a bibliometric analysis of studies on therapies for children with cerebral palsy from 2002 to 2011 retrieved from Web of Science. INCLUSION CRITERIA: (a) peer-reviewed published articles on botulinum toxin, constraint-induced movement therapy, or acupuncture for children with cerebral palsy indexed in Web of Science; (b) original research articles, reviews, meeting abstracts, proceedings papers, book chapters, editorial material, and news items; and (c) publication between 2002 and 2011. EXCLUSION CRITERIA: (a) articles that required manual searching or telephone access; (b) documents that were not published in the public domain; and (c) a number of corrected papers from the total number of articles. MAIN OUTCOME MEASURES: (1) Number of publications on the three therapies; (2) annual publication output, distribution by journals, distribution by institution, and top-cited articles on botulinum toxin; (3) annual publication output, distribution by journal, distribution by institution, and top-cited articles on constraint-induced movement therapy; (4) annual publication, distribution by journal, distribution by institution, and top-cited articles on acupuncture.
RESULTS: This analysis, based on Web of Science articles, identified several research trends in studies published over the past 10 years of three therapies for children with cerebral palsy. More articles on botulinum toxin for treating children with cerebral palsy were published than the articles regarding constraint-induced movement therapy or acupuncture. The numbers of publications increased over the 10-year study period. Most papers appeared in journals with a focus on neurology, such as Developmental Medicine and Child Neurology and Journal of Child Neurology. Research institutes publishing on botulinum toxin treatments for this population are mostly in the Netherlands, the United States of America, and Australia; those publishing on constraint-induced movement therapy are mostly in Australia and the United States of America; and those publishing on acupuncture are mostly in China, Sweden and the United States of America.
CONCLUSION: Analysis of literature and research trends indicated that there was no one specific therapy to cure cerebral palsy. Further studies are still necessary.

Research Highlights

We performed a bibliometric analysis of published studies on three common therapies to treat children with cerebral palsy from 2002 to 2011 retrieved from Web of Science. The three therapies were botulinum toxin, constraint-induced movement therapy, and acupuncture.

Abbreviation CIMT, constraint-induced movement therapy

INTRODUCTION

Cerebral palsy is a range of motor impairment and non-progressive posture syndromes[1]. It is attributed to non-progressive disturbances during brain development in fetuses or infants. Cerebral palsy is frequently accompanied by impaired cognition, communication and sensory perception, epilepsy, and behavioral abnormalities, or a combination of these features[23]. Cerebral palsy is a common cause of disability in childhood. The target of treatment is to achieve the best functional motor, language and intellectual status for children with cerebral palsy, and improve their ability to live and integrate into society[4]. We need comprehensive application of various treatment methods and techniques[56]. Management options include physiotherapy, occupational and speech therapy, orthotics, device-assisted modalities, pharmacological intervention, and orthopedic and neurosurgical procedures[1]. By searching Web of Science, we found three commonly used therapies: botulinum toxin, constraint-induced movement therapy (CIMT), and acupuncture. Botulinum toxin is commonly used to reduce spasticity and dystonia, and to improve range of movement and function in children with cerebral palsy. CIMT is an emerging approach for children with hemiplegic cerebral palsy that aims to increase spontaneous use of affected upper limbs and limit the effects of learned non-use. Acupuncture is commonly used in Asia and is said to stimulate the cerebral cortex and peripheral nerves, inducing reduced muscle tension to return to normal[78]. In this study, we analyzed research trends in these three therapies for children with cerebral palsy based on a bibliometric analysis of publications in Web of Science from 2002 to 2011.

DATA SOURCES AND METHODOLOGY

Data retrieval

This study used bibliometric analyses to quantitatively and qualitatively investigate research trends in studies of therapies for children with cerebral palsy. We searched Web of Science, a database of research publications and citations, selected and evaluated by the Institute for Scientific Information in Philadelphia, PA, USA. We found three common therapies: botulinum toxin, CIMT, and acupuncture. We then searched using the key words “cerebral palsy” and “child or infant”, along with either “botulinum toxin”, “constraint-induced movement therapy”, or “acupuncture” to find articles on the use of botulinum toxin, CIMT, or acupuncture, respectively, to treat children with cerebral palsy. We limited the period of publication from 2002 to 2011 and compiled a bibliography of all articles related to these therapies. We downloaded the data on August 4, 2012.

Inclusion criteria

Inclusion criteria were as follows: (1) published peer-reviewed articles on any of the three therapies, including original research articles, reviews, meeting abstracts, proceedings papers, book chapters, editorial material, and news items, which were indexed in Web of Science; (2) year of publication 2002–2011; and (3) citation database was Science Citation Index Expanded.

Exclusion criteria

We excluded articles that required manual searching or telephone access, documents that were not published in the public domain, and several corrected papers. Outcomes for all articles referring to the three therapies for treating children with cerebral palsy were assessed using the following criteria: (1) number of publications on the three therapies; (2) annual publication output on botulinum toxin; (3) distribution by journal on botulinum toxin; (4) distribution by institution on botulinum toxin; (5) most-cited articles from 2002 to 2011 on botulinum toxin; (6) annual publication output on CIMT; (7) distribution by journal on CIMT; (8) distribution by institution on CIMT; (9) most-cited articles from 2002 to 2011 on CIMT; (10) annual publication output on acupuncture; (11) distribution by journal on acupuncture; (12) distribution by institution on acupuncture; and (13) most-cited articles from 2002 to 2011 on acupuncture.

RESULTS

Search results for three therapies used to treat children with cerebral palsy from 2002 to 2011 (Table 1)

As shown in Table 1, there were 480 articles on the use of botulinum toxin to treat children with cerebral palsy, which is much more than those on the use of CIMT and acupuncture.

Table 1

Number of publications on three therapies for treating children with cerebral palsy from 2002 to 2011

Annual number of publications on botulinum toxin for treating children with cerebral palsy in Web of Science from 2002 to 2011.

Annual publication output relating to the use of botulinum toxin to treat children with cerebral palsy in Web of Science from 2002 to 2011 (Figure 1)

A total of 480 publications on botulinum toxin for treating children with cerebral palsy were retrieved from Web of Science from 2002 to 2011. The number of relevant publications increased over the 10-year study period; 36 papers were published and included in Web of Science in 2002, but the number of published papers had increased to 73 in 2010. However, the numbers of papers published heavily decreased in 2005, 2008 and 2011.

Distribution of output by journal for publications on use of botulinum toxin to treat children with cerebral palsy in Web of Science from 2002 to 2011 (Figure 2)

Developmental Medicine and Child Neurology published 68 papers, followed by Journal of Child Neurology, American Journal of Physical Medicine Rehabilitation, and Archives of Physical Medicine and Rehabilitation, which published 21, 18 and 18 papers, respectively (Figure 2).

Figure 2

Top 11 journals were selected based on the number of publications on botulinum toxin for treating children with cerebral palsy between 2002 and 2011.

I: Developmental Medicine and Child Neurology; II: Journal of Child Neurology; III: American Journal of Physical Medicine Rehabilitation; IV: Archives of Physical Medicine and Rehabilitation; V: Clinical Rehabilitation VI: Gait Posture; VII: Pediatric Neurology; VIII: Revista de Neurologia; IX: European Journal of Neurology; X: European Journal of Paediatric Neurology; XI: Journal of Rehabilitation Medicine.

Distribution of output by institution for publications on use of botulinum toxin to treat children with cerebral palsy in Web of Science from 2002 to 2011 (Figure 3)

A total of 480 articles were analyzed by institution. The Murdoch Children's Research Institute in Australia and the University of Munich in Germany were the most prolific research institutes (Figure 3). Four of the top 11 research institutes publishing in this field were in the Netherlands, three were in the United States of America.

Figure 3

The top 11 institutions for publications on botulinum toxin for treating children with cerebral palsy from 2002 to 2011.

I: Murdoch Childrens Research Institute, Australia; II: University of Munich, Germany; III: Radboud University Nijmegen, Netherlands; IV: The University of Melbourne, Australia; V: Yonsei University, Korea; VI: Catholic University of Leuven, USA; VII: Shriners Hosp For Children, USA; VIII: VU University Amsterdam, Netherlands; IX: Sint Maartensklin, Netherlands; X: The University of Auckland, New Zealand; XI: University of Washington, USA.

Highly cited papers on the use of botulinum toxin to treat children with cerebral palsy in Web of Science from 2002 to 2011 (Table 2)

A total of 480 papers on the use of botulinum toxin to treat children with cerebral palsy were cited in Web of Science from 2002 to 2011. “Cerebral palsy”, published in 2004 by the journal Lancet[1], was cited 118 times, which was more times than any other paper. Of the nine most-cited papers, two were published in Developmental Medicine and Child Neurology, two were published in Journal of Bone and Joint Surgery-British Volume; of these nine most-cited papers, five were published in 2004, two in 2003.

Annual number of publications on constraint-induced movement therapy for treating children with cerebral palsy in the Web of Science from 2002 to 2011.

Annual publication output relating to CIMT for treating children with cerebral palsy in Web of Science from 2002 to 2011 (Figure 4)

A total of 84 publications on the use of CIMT to treat children with cerebral palsy were retrieved from Web of Science from 2002 to 2011. The number of relevant publications increased over the 10-year study period.

Two papers were published and included in Web of Science in 2002, but the number of published papers increased to 20 in 2011. However, numbers of papers published slightly decreased in 2004, 2008 and 2010.

Distribution of output by journal for publications on use of CIMT to treat children with cerebral palsy in Web of Science from 2002 to 2011 (Figure 5)

As shown in Figure 5, Developmental Medicine and Child Neurology published 13 papers, followed by Physical Therapy, which published five papers.

Figure 5

Top 11 journals were selected based on the number of publications on CIMT for treating children with cerebral palsy between 2002 and 2011.

I: Developmental Medicine and Child Neurology; II: Physical Therapy; III: American Journal of Occupational Therapy; IV: American Journal of Physical Medicine Rehabilitation; V: Archives of Physical Medicine and Rehabilitation; VI: Journal of Child Neurology; VII: Neurorehabilitation and Neural Repai; VIII: Pediatrics; IX: Research in Developmental Disabilities; X: Developmental Neurorehabilitation; XI: Disability and Rehabilitation.

Distribution of output by institution for publications on use of CIMT to treat children with cerebral palsy in Web of Science from 2002 to 2011 (Figure 6)

A total of 84 articles were analyzed by institution. Columbia University in the United States of America, Emory University in the United States of America, the University of Queensland in Australia and Howard Florey Institute in Australia were the most prolific research institutes (Figure 6). Of the top 11 research institutes publishing in this field, five are in Australia, three are in the United States of America.

Figure 6

The top 11 institutions for publications on CIMT for treating children with cerebral palsy from 2002 to 2011.

I: Columbia University, USA; II: Emory University, USA; III: University of Queensland, Australia; IV: Howard Florey Institute, Australia’ V: Austin Research Institute, Australia; VI: Karolinska Institute, Swedish; VII: Murdoch Childrens Research Institute, Australia; VIII: The University of Alabama System, USA; IX: University of Children's Hospital, Germany; X: Federal University of Minas Gerais, Brazil; XI: The University of Melbourne, Australia.

Highly cited papers on the use of CIMT to treat children with cerebral palsy in Web of Science from 2002 to 2011 (Table 3)

A total of 84 papers on the use of CIMT to treat children with cerebral palsy were cited in Web of Science from 2002 to 2011.

“Efficacy of constraint-induced movement therapy for children with cerebral palsy with asymmetric motor impairment”, published in 2004 by the journal Pediatrics [17], was cited 123 times—more times than any other paper on this topic. Of the 10 most-cited papers, five were published in Developmental Medicine and Child Neurology, two in Pediatrics; of these 10 most-cited papers, three were published in 2005, two each in 2006 and 2007.

Annual number of publications on acupuncture for treating children with cerebral palsy in the Web of Science from 2002 to 2011.

Annual publication output relating to the use of acupuncture to treat children with cerebral palsy in Web of Science from 2002 to 2011 (Figure 7)

A total of 35 publications on the use of acupuncture to treat children with cerebral palsy were retrieved from Web of Science from 2002 to 2011. The number of relevant publications changed irregularly over the 10-year study period; 10 papers were published and included in Web of Science in 2008, seven papers in 2009, and fewer than five papers in each of the other years.

Distribution of output by journal for publications on the use of acupuncture to treat children with cerebral palsy in Web of Science from 2002 to 2011 (Figure 8)

Developmental Medicine and Child Neurology and Journal of Child Neurology each published four papers, three papers were in Journal of Alternative and Complementary Medicine, and two papers each were in European Journal of Paediatric Neurology, Neural Regeneration Research (Figure 8).

Figure 8

Top five journals were selected based on the number of publications on acupuncture for treating children with cerebral palsy between 2002 and 2011.

I: Developmental Medicine and Child Neurology;

II: Journal of Child Neurology;

III: Journal of Alternative and Complementary Medicine;

IV: European Journal of Paediatric Neurology;

V: Neural Regeneration Research.

Distribution of output by institution for publications on the use of acupuncture to treat children with cerebral palsy in Web of Science from 2002 to 2011

A total of 35 articles were analyzed by institution. The University of Hong Kong in China and Capital Medical University in China were the most prolific research institutes (Figure 9). They published five and three papers, respectively. And there was another prolific research institute in China that is Chinese People's Liberation Army General Hospital. Of the other five top research institutes publishing in this field, two were in Sweden, another two were in the United States of America, and one institute was in Canada.

Figure 9

The top eight institutions for publications on acupuncture for treating children with cerebral palsy from 2002 to 2011.

I: University of Hong Kong, China; II: Capital Medical University, China; III: Chinese People's Liberation Army General Hospital, China; IV: Örnsköldsviks Hospital, Sweden; V: University of Alberta, Canada; VI: University of Arizona, USA; VII: University of California System, USA VIII: University of Gothenburg, Sweden.

Highly cited papers on the use of acupuncture to treat children with cerebral palsy in Web of Science from 2002 to 2011 (Table 4)

A total of 35 papers on the use of acupuncture to treat children with cerebral palsy were cited in Web of Science from 2002 to 2011. “Complementary and alternative medicine use in families of children with cerebral palsy”, published in 2003 by Developmental Medicine and Child Neurology[27], was cited 35 times—more times than any other paper on this topic. Of the 10 most-cited papers, two were published in Developmental Medicine and Child Neurology.

DISCUSSION

Bibliometric analysis, based on Web of Science publications, identified several research trends over the past 10 years in studies of botulinum toxin, CIMT and acupuncture as treatments for children with cerebral palsy. Many more articles have been published on the use of botulinum toxin to treat these children than on the use of CIMT or acupuncture. Although the number of publications increased over the 10-year study period, the increase was irregular. Most papers appeared in journals with a focus on neurology, such as Developmental Medicine and Child Neurology, Journal of Child Neurology. Research institutes publishing on the use of botulinum toxin to treat children with cerebral palsy are mostly in the Netherlands, the United States of America, and Australia; those publishing on the use of CIMT to treat these children are mostly in Australia and the United States of America; and those publishing on the use of acupuncture to treat them are mostly in China, Sweden and the United States of America. So far, there is no one specific therapy that can cure cerebral palsy effectively alone. There are more than 10 types of treatments for cerebral palsy. Doctors are inclined to use comprehensive applications of two or three treatments[3738]. Botulinum toxin is commonly used to reduce spasticity and dystonia in children with cerebral palsy. CIMT is emerging as a treatment approach for children with hemiplegic cerebral palsy. Acupuncture, developed as a school of its own, has made progress in terms of basic research and clinical applications. Because of the complex pathogenesis of cerebral palsy and the wide variation in associated brain damage, clinical treatment of cerebral palsy is difficult [3940]. Single treatments rarely achieve the desired therapeutic effect; comprehensive approaches are necessary, possibly with a regimen of various integrated treatments[414243]. We should pay attention to the relevance and effectiveness of treatment methods and options.

Table 2

The top nine cited papers on botulinum toxin for treating children with cerebral palsy from 2002 to 2011

Table 3

The top 10 cited papers on constraint-induced movement therapy for treating children with cerebral palsy from 2002 to 2011

Table 4

The top 10 cited papers on acupuncture for treating children with cerebral palsy from 2002 to 2011