Executive Committee used this information and additional A report: the definition comments from the international community to generate a report on the Definition and Classification of , and classification April 2006. The Executive Committee presents this report with the intent of providing a common conceptualization of CP for of cerebral palsy use by a broad international audience. Cerebral palsy (CP) is a well-recognized neurodevelopmental April 2006 condition beginning in early childhood and persisting through the lifespan. Originally reported by Little in 1861 (and origi- nally called ‘cerebral paresis’), CP has been the subject ofbooks Report Executive Committee: and papers by some of the most eminent medical minds of Peter Rosenbaum (Definition Panel Chair) MD, CanChfld the past one hundred years. At the end of the 19th century, Centre for Childhood Disability , Hamilton, Ontario, Sigmund Freud and Sir William Osler both began to contribute Canada. important perspectiveson the condition. From the mid-l940s, Nigel Paneth (Classification Panel Chair) MD, Department of the founding fathers of the American Academy for Cerebral Epidemiology, Michigan State University, East Lansing, MI, USA. Palsy and Developmental Medicine (Carlson, Crothers, Deaver, Alan Leviton MD, Neuroepidemiology Unit, Children’s Fay, Perlstein, and Phelps) in the United States, and Mac Keith, Hospital, Boston, MA, USA. Polani, Bax and Ingram of the Little Club in the United Kingdom, Murray Goldstein* (Co-Chair) DO, MPH, United Cerebral Palsy were among the leaders who moved the concepts and descrip- Research & Educational Foundation, Washington DC, USA. tions of CP forward and caused this condition to become the Martin Bax (Co-Chair) DM, FRCP, Division of Paediatrics, focus of treatment services, advocacy, and research efforts. Obstetrics and Gynaecology,Imperial College, London, UK. It has always been a challenge to define ‘cerebral palsy’, as documented by the number of attempts that have been made Panel Consultants: over the years. For example, Mac Keith and Polani (1959) Diane Damiano PhD PT,Washington University Department of defined CP as ‘a persisting but not unchanging disorder of , St. Louis, MO, USA. movement and posture, appearing in the early years of life Bernard Dan MD, PhD, H6pital Universitaire des Enfants, and due to a non-progressive disorder of the brain, the result Reine Fabiola,Universite Libre de Bruxelles,Brussels, Belgium. of interference during its development.’ In 1964, Bax report- Bo Jacobsson MD, PhD, Perinatal Center, Sahlgrenska ed and annotated a definition of CP suggested by an interna- University Hospital East, Goteborg, Sweden. tional working group that has become a classic and is still used. It stated that CP is ‘a disorder of movement and pos- *Correspondence to Murray Goldstein, UCP Research and ture due to a defect or lesion of the immature brain.’ Though Educational Foundation; Suite 700,1660 L Street Nvz: this brief sentence is usually all that is cited by authors, addi- Washington, DC, USA 20036. tional comments were added by Bax: ‘For practical purposes it is usual to exclude from cerebral palsy those disorders of posture and movement which are (1) ofshort duration, (2) due to progressive disease, or (3) due solely to mental deficiency.’ The group for which Bax was the reporter felt that this simple For a variety of reasons, the definition and the clawification of sentence could be readily translated into other languages cerebral palsy (CP) need to be reconsidered. Modern brain and hoped that it might be universally accepted. At that time, imaging techniques have shed new light on the nature of the it was felt that it was wiser not to define precisely what they underlying brain injury and studies on the neurobiology of and meant by ‘immature brain’, as any such definition might limit pathology associated with brain development have further services to those in need. Like its predecessors, this formula- explored etiologic mechanisms. It is now recognized that tion of the CP concept placed an exclusive focus on motor assessing the extent of activity restriction is part of CP aspects, and also stressed the specific consequences of early as evaluation and that people without activity restriction should opposed to late-acquiredbrain damage. Not formally included not be included in the CP rubric. Also, previous definitions have in the concept were sensory, cognitive, behavioral and other not given sufficient prominence to the non-motor associated impairments very prevalent in people with ‘disor- neurodevelopmental disabilities of performance and behaviour dered movement and posture due to a defect or lesion of the that commonly accompany CP, nor to the progression of immature brain’, and often significantly disabling. musculoskeletal difficulties that often occurs with advancing The heterogeneity of disorders covered by the term CP, as age. In order to explore this information, pertinent material was well as advances in understanding of development in infants reviewed on July 11-13,2004 at an international workshop in with early , led Mutch and colleagues to modify Bethesda, MD (USA) organized by an Executive Committee and the definition of CP in 1992 as follows: ‘an umbrella term participated in by selected leaders in the preclinical and clinical covering a group of non-progressive, but often changing, sciences. At the workshop, it was agreed that the concept motor impairment syndromes secondary to lesions or anom- ‘cerebral palsy’ should be retained. Suggestions were made alies of the brain arising in the early stages of development.’ about the content of a revised definition and classification of CP This definition continued to emphasize the motor impairment that would meet the needs of clinicians, investigators, health and acknowledged its variability, previously underscored in the officials, families and the public and would provide a common MacKeith and Polani definition; it also excluded progressive language for improved communication. Panels organized by the disease, a point introduced in Bax’s annotation.

8 Definition and Classification of CP In response to the emerging need to evaluate the status of more significant in different persons or at different life periods, information about cerebral palsy and revisit the language e.g. some aspects of the motor impairment, sensory loss, intel- presently used to describe it, an International Workshop on lectual disability, attentional difficulty, epilepsy, musculoskeletal Definition and Classification of Cerebral Palsy was held in dysfunction and many others maybe more prominent or more Bethesda, Maryland (USA), on July 11-13 2004, co-sponsored problematic at different stages of the life of a person with CP by United Cerebral Palsy Research and Educational Foundation in the USA and the Castang Foundation in the United Kingdom: References support was provided by the National Institutes of Health/ 1. Freud S. (1897) Die infantile Cerebrallahmung. In: Nothnagel H, editor. SpecieIIePathoIogie und Therapie,Bd IX,Teil 111. Vienna: National Institute of Neurological Disorders and Stroke and Holder. p 1-327. the Dana Foundation. The task of the participants (listing fol- 2. Osler W (1899) 7&eCerebral Palsies of Children.A CIinicaI Study lows) was to revisit and update the definition and classifica- for thelnffrmaryfor Nervous Diseases. Philadelphia: Blakiston. tion of cerebral palsy in light of emerging understanding of 3. Little Club. (1959) Memorandum on terminology and classification of ‘cerebral palsy’. (Mac Keith R, et al., editors) developmental neurobiology and changing concepts about Cereb Palsy Bull 1: 27-35. impairments, functional status and personal ‘participation’. 4. Bax MCO. (1964) Terminology and classification of cerebral palsy. Reassessment of the definition of CP was prompted by a host Dev Med ChiIdNeurol6:295-307. of factors: changes in delivery of care to children with disabil- 5. Mutch LW Alberman E. Hagberg B, Kodama K, Velickovic MV ities; recognition that children with slowly progressive inborn (1992) Cerebral palsy epidemiology: where are we now and where are we going?Dev Med Child NeuroI 34: 547-555. errors of metabolism can present with motor difficulties at times indistinguishable from those of children with nonpro- gressive disease; increased availability of high-quality brain What follows is: The Defrnition and C1 assifiwion of imaging to identify impairments in brain structure; acknowl- Cerebral Palsv. Aod 2006, an annotated explanation of edgment that developmental motor impairment is almost the terms used, and the thinking behind the choice of invariably associated with a range of other disabilities; and those words. This material was authored by the members of increased understanding about associated antecedents and the Executive Committee functioning in panels enriched with correlates of CP expertise from consultants and by comments and suggestions The Workshop participants agreed that CP as conceptual- from many reviewers responding to drafts provided to the ized previously had proved to be a useful nosologic construct, international community. The Definition and Classification but that previous definitions had become unsatisfactory. They of Cerebral Palsy, April 2006 document is offered for interna- underlined that CP is not an etiologic diagnosis, but a clinical tional consensus and adoption, with the intent of providing a descriptive term. Reservations were expressed about the exclu- broad spectrum of audiences with a common conceptualiza- sive focus on motor deficit, given that persons with neurode- tion about cerebral palsy. velopmental disabilities often present impairments of a wide range of functions that may or may not include severe motor I. Definition of cerebral palsy manifestations, thereby calling for the need of an individual- Cerebralpalsy (CP) descri&esa group ofpetmanent dis- ized, multidimensional approach to each affected person’s orders of the development of movement and posture, functional status and needs. However, it was suggested that causing activity limitation, that are attri&uted to non- the concept ‘cerebral palsy’ be retained to serve diagnos- progressive disturbances that occurred in the develop tic, management, epidemiologic, public heath, and research ingfetal or infant brain. TEw motor disorhof cerebral purposes. It was felt that an updated definition of CP, taking palsy are oflen accompanied by disturbances of sensa- into account recent advances in the understanding of the tion, perception, cognition, communication, and bebav- physiology of and pathology associated with brain develop- but; by epilepsy, and by secondary musculoskeletal ment, as well as changes in terminology, should be developed probh. for international use. The updated definition needed to meet the requirements associated with these purposes, as ANNOI’ATION well as to enhance communication among clinicians, scien- Cerebralpalsy(CP)’describesagroup20fpermanent3disorders* tists and the public. As in the prior concept, it was agreed that of the development5 of movement and posture6 causing’ the motor disorder needed to be emphasized;however, activity limitation,n that are attributed to9 non-progressive10 recognition should be provided that other developmen- disturbances” that occurred in the developing fetal or infant12 tal disorders of performance and behaviour can and brain. l3 The motor disorders of cerebral palsy are often accom- often do accompany it. This emphasis on the motor disor- panied byI4 disturbances of ~ensation,’~perception16, cogni- der is stipulated in that children with CP most often present tion,” communication, and behaviour, by epilepsy20,and by for medical attention because of motor abnormalities, even if secondary musculoskeletal problems.21 they have other developmental problems. To underline the idea that a comprehensive approach to COMMENTARY ON THE TERMS AND CONCEPTS CP needs to be multidimensional and that management of It is hoped this annotation of the definition will clarify the CP patients with CP almost always requires a multidisciplinary concept and allow unified use of the term both within and setting, classes of disorders commonly accompanying CP have across the concerned fields. As it relies essentially on clinical been identified and included in the revised definition. This aspects and does not require sophisticated technology, it addition reflects the concept that CP is one group of neu- should be possible to apply this definition very widely. rodevelopmental disorders which involve numerous devel- 1. ‘Cerebral palsy (CP)’ - It is generally agreed that the CP oping functions. As in other neurodevelopmental disorders, concept, essentially a clinical formulation based on phenome- various manifestations of the disordered brain may appear nology, remains useful in the current state of nosology, insofar

Definition and Classification of CP April 2006 Peter Rosenbaum et aI. 9 as the term describes a prevalent, clinically important and This term amplifies the previous WHO concept of ‘disability’to identifiable group of persons with neurodevelopmental dis- recognize changing international concepts and terminology. abilities. Although the word ‘palsy’has become largely obso- 9. ‘attributed to’ - Understanding of developmental neu- lete in medical nosography and has no univocal connotation, robiology (including genetic, biochemical, and other influ- the term ‘cerebral palsy’ is established in the literature and ences on brain development) is increasing rapidly, such that is used universally by clinicians, therapists, epidemiologists, it is becoming possible to identify structural and other evi- researchers, policy makers, health care funding organization dence of brain maldevelopment in people with CP As a con- and laypersons.The term ‘CP has, however, beenvariablyused, sequence, structural-functional connections and correlations with poor comparability across different places and times, are becoming more clearly delineated than has previously indicating the need for an internationally acceptable defini- been possible. It must, however, be acknowledged that at the tion. The term cerebral palsy (CP) has been retained to relate present time a full understanding of causal pathways and future research in CP to existing published work. mechanisms leading to cerebral palsy remains elusive. The following explanations are offered to clarify several 10. ‘non-progressive’ - The term non-progressive is used aspects of the definition of CP: to denote that the pathophysiological mechanisms leading 2. ‘a group’ -There is general agreement that CP is a het- to CP are presumed to arise from a single, inciting event or erogeneous condition in terms of aetiology as well as in types discrete series of events which are no longer active at the time and severity of impairments. Several groupings are possible of diagnosis. This inciting event@)produce(s) a disruption of and warranted to serve different purposes. These groupings normal brain structure and function which may be associated may show overlap. Therefore, the singular form ‘CP’ is used with changing or additional manifestations over time when (as opposed to ‘cerebral palsies’). superimposed on developmental processes. Motor dysfunc- 3. ‘permanent’ - This definition excludes transient disor- tion which results from recognized progressive brain ders, but recognizes that children and adults have changing disorders is not considered CP. patterns of clinical manifestations. 11. ‘disturbances’-This term refers to processes or events 4. ‘disorders’ - This refers to conditions in which there is that in some way interrupt, damage or otherwise influence disruption of the usual orderly processes of child development. the expected patterns of brain formation, development and 5. ‘development’- The notion of alteration in children’s maturation, and result in permanent (but non-progr