Having Another Look at Cerebral Palsy: Current Definitions and Classification Systems

By Mary Rainey Perry

Setting the Scene

During many years of work with children with cerebral palsy, including clinical work, supervising music therapy students on clinical practice, and a qualitative research project, I have noticed that the diagnostic label “cerebral palsy” (CP) is one that has less prominence in music therapy literature than other diagnostic labels (for example, autism spectrum disorders). It appears to be more common to use general terms such as “physical disability”, or “multiple disability.” As I became aware of a little of the wider literature in cerebral palsy, it also seemed like the work of music therapists was largely invisible to the wider CP community, and that the music therapy community was using different descriptive and classification frameworks when describing the motor function of individuals with cerebral palsy in case study and other reports. This article reflects my struggles (and sometimes my ambivalence) regarding these issues. It is intended to provoke thought and discussion amongst music therapy clinicians, authors, and researchers who currently work with children and adults with cerebral palsy.

Introduction

Music therapy clinicians have a long history of work with individuals with cerebral palsy, which continues in special education, early intervention, medical, palliative care, and adult disability contexts. Despite early interest in cerebral palsy in music therapy literature (Bixler, 1968; Schneider, 1968), the term is less prominent in current music therapy literature. Two current articles that do make specific mention of cerebral palsy are Ahonen-Eerikäinen, Lamont, & Knox (2008) and Kwak (2007). The work of Ahonen-Eerikäinen, Lamont, & Knox (2008) reflects current perspectives on cerebral palsy, and their article is an excellent example of the type of literature that raises awareness of music therapy in the wider community concerned with cerebral palsy. The work of these authors frames a music technology project specifically developed for individuals with severe physical disability in terms of engagement and participation. Kwak (2007) addresses physical function in cerebral palsy (the effect of auditory rhythmic stimulation of gait performance). This article is also an important addition to literature about cerebral palsy and music therapy. In addition to articles such as these, individuals with cerebral palsy are often included in case study descriptions about those with a range of developmental disabilities, particularly severe and multiple disabilities. Others in this more general group often have some degree of physical disability along with severe or profound intellectual impairment, but may not have the degree or type of physical disability of individuals with cerebral palsy.

Can shifting the focus from a general group with developmental disability, to increased focus on cerebral palsy as a diagnostic group provide a useful perspective for music therapy clinicians and researchers? Can current cerebral palsy literature (including using common terms and classification scales) provide some useful tools for music therapy clinicians and researchers? I believe having another look at cerebral palsy can assist in refining our clinical practice and research. It will also improve our communication about clinical practice and research and increase awareness of music therapy by others concerned with cerebral palsy (medical, paramedical, and education professionals, families, and the wider community).

Current Definitions and Perspectives on Practice

Despite the long history of cerebral palsy as a clinical entity, it may be surprising to hear that definitions of the condition are still evolving and not agreed upon in every detail by leading clinicians and researchers in the field. There is general agreement on a number of points, and there is also agreement that the condition includes a wide range of functioning levels and additional impairments. There are extensive international efforts to refine definitions and develop a range of classification and assessment tools. Current models of understanding cerebral palsy focus on participation, engagement, quality of life, as well as physical function. There is still much to be discovered about the efficacy of all types of interventions and what the relationship might be to the impairments presented and the brain impairment evident from current brain scanning techniques such as MRI. One commonly encountered definition is:

Cerebral palsy (CP) describes a group of disorders of the development of movement and posture, causing activity limitation, that are attributed to non-progressive disturbances that occurred in the developing fetal or infant brain. The motor disorders of cerebral palsy are often accompanied by disturbances of sensation, cognition, communication, perception, and/or behaviour, and/or by a seizure disorder. (Rosenbaum et. al 2005, p. 572)

Rosenbaum (2003) notes that “recognising and managing cerebral palsy’s many important comorbidities is as important as treating the motor disabilities” (p. 970). Acknowledgment of the importance of the full nature of impairments encountered places music therapy interventions in the mainstream of cerebral palsy intervention. Because of the heterogenous nature of the group and these common additional impairments, simply describing or classifying motor skills will not reflect the whole focus of intervention in music therapy (or other therapies and educational approaches). Music therapists also have useful skills to contribute to efforts to increase musical and social participation in the community, and to improve the quality of life for individuals with cerebral palsy and their families.

The Influence of Physical Ability and Disability on Active Music Therapy Methods and How Classification Scales can be Useful for Music Therapists

It is fairly easy to see that when a music therapy intervention is focused on physical goals such as gait, or trunk and head control, an accurate description of physical disability is needed. What if the music therapy aims are within the realms of communication, cognitive skills, or social development? Musical participation involves the use of motor skills, including oromotor, gross motor, and fine motor skills. Indeed, skilled musicians are often described as athletes of the little muscles. Although as music therapists, we do not require our clients to have that level of motor skill, motor skills do affect how clients are able to engage in active music therapy methods. The level of motor skill impairment influences the ability of clients to access singing and conventional instruments and also influences the selection of alternative means of access such as special adaptations or positioning and use of electronic music technology (switches, motion sensors, computer systems). Thoms (2004) describes some of the specific difficulties that may be involved in accessing conventional instruments effectively, including difficulties with moving at all, directing movement, grasp, using sufficient speed and force, and ability to use individual fingers. On reflecting on my own case study research (Perry, 1999, 2003), although all seven participants with cerebral palsy had significant physical disability and complex communication needs (pre-intentional or early intentional communication skills), their ability to use musical instruments and voice expressively varied significantly. In retrospect, if functional classification schemes had been available when reporting this research, it would have provided another level of useful description for those wishing to judge the relevance of the responses described to work with other children. Music therapy research sometimes uses descriptions referring to relying on a wheelchair for mobility, as a description of motor impairment. However, individuals with a range of motor disability are reliant on wheelchairs for mobility, especially for mobility in the community or for longer distances. Use of the current classification scales such as the Gross Motor Function Classification Scale (GMFCS) conveys a more accurate description of motor abilities.

I believe it is important to have a clear idea of the level of functional motor ability when selecting interventions and describing individuals’ involvement in music therapy, and motor classification scales can assist in this. In addition, understanding the level of motor function can assist in facilitating active involvement in music, whether this involves positioning, hands-on facilitation, or use of technology to assist active involvement. Inclusion of current classification scale levels, including the GMFCS and the Manual Ability Classification Scale (MACS), as well as careful description of additional impairments in research reports will also be useful for clinicians when selecting interventions and when comparing research outcomes with clinical practice. Awareness of future assessments and classification scales in areas such as functional communication and oromotor skills will also be useful when developing future clinical reports and research in music therapy.

Classification Scales in Cerebral Palsy

Classifying the type of cerebral palsy has included the pattern of limb involvement, type of muscle impairment, and severity. There are difficulties in accurately describing the severity of motor impairment by using terms such as mild, moderate, and severe. Functional classification systems such as the Gross Motor Function Classification Scale (GMFCS) (Palisano, R.J. et al, 2000) are increasingly used as a means of describing the level of gross motor function (See Table 1). Because of the importance of gross motor function to overall development from birth, these classifications also have significant ramifications for the overall development of the child, the type of interventions needed, and the likely outcome in terms of gross motor development and possible future deformity. Additional classification of upper limb function is provided by the Manual Ability Classification Scale (MACS) (Eliasson, A.C., et al, 2006) (see Table 2). (Tables 1 and 2 provide a brief example and summary of the Scales. However, proper determination of the level involves use of detailed manuals for determining each level and age guidelines. Often physiotherapists and occupational therapists are consulted to determine the appropriate level for each child). As yet there is no classification of oromotor ability, which could be of particular interest to music therapists using approaches involving client vocalisation. A system of classification of functional communication abilities is currently under development. (Hidecker et. al. 2008). There is some correlation between pattern and type of limb involvement and GMFCS level, with hemiplegia more common at Level I (Gorter, JW et. al. 2004). As classification scales are a recent development, they are currently only valid for children and sometimes adolescents. In addition to classification scales, there are also an increasing number of assessments for various aspects of cerebral palsy related to participation and quality of life (Krigger, K.W. 2006).

Table 1. Gross Motor Function Classification System for Children with Cerebral Palsy 6-12 years.
Palisano, R.J., Hanna, S.E., Rosenbaum, P.L., Russell, D.J., Walter, S.D., Wood, E.P., Raina, P.S., Galuppi, B. E. (2000). For further information refer to: www.canchild.ca/en/measures/gmfcs.asp
I.Walks without restrictions; limitations in more advanced gross motor skills.
II.Walks without assistive devices; limitations walking outdoors and in the community.
III.Walks with assistive mobility devices; limitations walking outdoors and in the community.
IV.Self-mobility with limitations; children are transported or use power mobility outdoors and in the community.
V.Self-mobility is severely limited even with the use of assistive technology.

Table 2. Manual Ability Classification System for Children with Cerebral Palsy 4-18 years.
Eliasson AC, Krumlinde Sundholm L, Rösblad B, Beckung E, Arner M, Öhrvall AM , Rosenbaum P. (2006). For further information refer to: www.macs.nu
I.Handles objects easily and successfully. At most, limitations in the ease of performing manual tasks requiring speed and accuracy. However, any limitations in manual abilities do not restrict independence in daily activities.
II.Handles most objects but with somewhat reduced quality and/or speed of achievement. Certain activities may be avoided or be achieved with some difficulty; alternative ways of performance might be used but manual abilities do not usually restrict independence in daily activities.
III.Handles objects with difficulty; needs help to prepare and/or modify activities. The performance is slow and achieved with limited success regarding quality and quantity. Activities are performed independently if they have been set up or adapted
IV.Handles a limited selection of easily managed objects in adapted situations. Performs parts of activities with effort and with limited success. Requires continuous support and assistance and/or adapted equipment, for even partial achievement of the activity.
V.Does not handle objects and has severely limited ability to perform even simple actions. Requires total assistance.

Two Case Vignettes

These case vignettes describe children who have contrasting patterns of physical functioning, especially manual ability, which affect ability to engage in musical interaction. Although these two children could both be described as having severe and multiple disabilities, their ability to access conventional means of musical interaction is different. This also affects their ability to use these instruments expressively and interactively. Later case examples will show even more marked contrasts in ability to engage in active music making in children with MACS levels ranging from I to IV.

Both children have sensory and other additional impairments. Each child is involved in active group and/or individual music therapy, with aims related to communication and cognitive skills. This is carried out in the context of a collaborative approach that also addresses physical goals in all programs. These vignettes will focus on each child’s ability to access musical interaction in the service of these aims.

Coby

Coby is a 10 year old boy with spastic quadriplegia, epilepsy, and visual and hearing impairments. His GMFCS level is V (“Self-mobility is severely limited even with the use of assistive technology”), and his MACS level is IV (“Handles a limited selection of easily managed objects in adapted situations”). He shows interest in and is motivated by music, especially playing instruments such as the guitar and keyboard. With appropriate support and positioning in his wheelchair, he is able to independently strum the guitar placed on his tray, as well as play the keyboard (finding some functions by random experimentation that the therapist did not know existed!). He is able to vocalise freely and expressively, although he does not always do so consistently. Outcomes in music therapy have included improved attention to and engagement in group activities and using electronic communication devices, pictographs, voice, and gesture to participate, request, and choose.

Lachlan

Lachlan is a 9 year old boy who also has spastic quadriplegia, epilepsy, and visual and hearing impairments. His hearing impairment is more severe than Coby’s. He has had a cochlear implant since he was 2 years old. His GMFCS level is V (“Self-mobility is severely limited even with the use of assistive technology”), and his MACS level is V (“Does not handle objects and has severely limited ability to perform even simple actions”). Outcomes in individual and group therapy include increased alertness and interest during music therapy, as indicated by holding his head up (he has very poor head and trunk control), and consistent attempts to use a head switch to participate (when alert). He is beginning to show interest in tempo contrasts and a variety of sounds in the music therapy setting. Lachlan is unable to access conventional musical instruments, even with extensive physical facilitation, adaptation, and positioning. He is able to use a head switch and has shown sustained ability to use the switch to activate single percussion sounds, recorded vocal sounds, and rhythmic/melodic loops using a music technology program (Special Access Kit). He is only able to vocalise very softly and inconsistently.

Both of these children could be described as having multiple and severe disabilities. However, the music therapy tools used differed, partly related to their level of fine motor impairment. Although low tech alternatives were also employed with Lachlan (vocal turn taking, pairing music to his changes in alertness and posture, and coactive playing of instruments), switch activated music technology provided him with considerably more opportunities to independently make music, especially in the group situation. Likewise, switch activated music technology was also used by Coby in the group situation, but conventional instruments were particularly motivating for him, including motivating him to communicate more consistently and to use more conventional means of communication.

Exploring Issues in Active Music Therapy Methods Using MACS

To make a preliminary step toward comparing and contrasting the ability to engage in active music making of children with various levels of GMFCS and MACS, I examined student files and music therapy notes of current clients aged 5-12 at a special school. Although I first considered and compared children based on both GMFCS and MACS, I found that MACS provided a more useful reflection of ability to engage in active music making. Frequently manual ability as reflected by MACS level is consistent with gross motor function as reflected by the GMFCS, but this is not always the case. Manual abilities are also influenced by factors such as tactile defensiveness and sensory impairment. However, as the MACS is a functional scale (reflecting what children do rather than what they may be capable of in the best-case scenario), the effect of these additional impaiments will be reflected in their level in this scale. Oral motor ability is not directly reflected in either of these scales, although individuals at higher levels may experience difficulties with respiratory and trunk control that affect oral motor abilities and this is reflected in difficulties with vocalisation. The following case examples reflect some of the contrasts that may occur in children with CP in their ability to engage in active music making. It must be emphasised that this is an attempt to present common abilities and patterns, and is not meant to be a comprehensive description of the effect of different MACS levels during active music therapy methods.

Leo is a young boy with diplegia. He has a MACS Level of I (“Handles objects easily and successfully”) and a GMFCS level of II (“Walks without assistive devices; limitations walking outdoors and in the community”). He is able to sing, including lyrics, and play percussion instruments with good ability to use both hands, vary tempo and volume, and imitate and create rhythmic patterns.

Alex is a young boy with hemiplegia. He has a MACS Level of II (“Handles most objects but with somewhat reduced quality and/or speed of achievement”), and a GMFCS level of II (“Walks without assistive devices; limitations walking outdoors and in the community”). He has difficulty with speech and vocalisation, but is improving his ability to use single words and phrases and to sing with some lyrics (not always intelligible). He tries hard to use both hands to play guitar and drums. He is able to play expressively and to lead and follow during improvisation.

Candy is a young girl with quadriplegia. Her MACS Level is III (“Handles objects with difficulty; needs help to prepare and/or modify activities”), and her GMFCS level is IV (“Self-mobility with limitations; children are transported or use power mobility outdoors and in the community”). She has difficulty with bilateral strength and coordination, and significant difficulties with attention and concentration. Candy is verbal, and enjoys singing. She is able to complete phrases in familiar songs but has more difficulty in singing together with others. Her vocal volume is very low.

Lila is a young girl with quadriplegia. Her MACS level if IV (“Handles a limited selection of easily managed objects in adapted situations”) and GMFCS level is also IV (“Self-mobility with limitations; children are transported or use power mobility outdoors and in the community”). She finds music quite engaging. She is able to hold and play instruments such as shakers, and to tap drums or piano with her hands. However, she has difficulty sustaining playing and grasp. She is able to approximate words and vocal inflection, but does not generally sustain vocal sounds unless she is distressed.

In the children I considered at MACS levels I-IV, all had the ability to engage in music making with conventional instruments and/or voice. Differences as level increased included more difficulty with bilateral movements and fine motor control. At level I, fluid ability to shift tempo, play single keys on the piano, and use both hands was present. In contrast, at levels III and IV, difficulties with strength, grasp, and bilateral coordination meant that adaptations and positioning were increasingly important, as was instrument selection, favouring instruments that could be accessed using one hand. When I considered students at MACS level V, there was a noticeable difference between these students and those at levels I-IV. For these students, the use of adaptations and technology was vital. They were generally unable to grasp, and instruments such as chimes were the main conventional instruments that were accessible. Considering this group is a major factor in my interest in encouraging music therapists to include MACS and GMFCS in clinical and research descriptions—simply using the terms such as “severe physical disability” does not quite capture this significant difference.

Discussion of Relating MACS to Active Music Therapy

In this preliminary look at some children with CP, I found (not surprisingly!) increasing difficulty accessing conventional means of music making as MACS level increased. This would be an interesting area to explore more systematically. There was still considerable variation in individual adaptations, selection, or preference for instruments. As MACS level increased, it became more important to offer opportunities for alternative means of accessing musical participation, such as those activated by switch systems or those that were movement activated (Soundbeam). This was particularly important to provide the experience of independent participation and initiation. However, the experience of playing conventional instruments is still valued by a number of these children despite these difficulties. Independence and expressive possibilities using conventional instruments are more limited, though. The option of music technology needs to be seriously considered as an option for many children with CP especially at higher MACS levels (III, IV & especially V). The eventual development of music technology with increased dynamic expressive abilities (Lem, Paine & Drummond, 2008) will extend the possibilities for active musical expression, engagement, and participation.

Voice continued to provide a means of expressive musical interaction for some at all levels, but was only accessed with great difficulty, inconsistently, or not at all for others. Again, this was quite variable and systems that focus on manual or gross motor abilities do not necessarily reflect oromotor abilities. Certainly, those with GMFCS V may experience more difficulty with respiratory support required for vocalising due to poor trunk control and head control. However with appropriate positioning and support, many were able to vocalise freely and expressively. It may be that future classification systems for oromotor involvement will be useful when comparing research and clinical reports of individuals with cerebral palsy participating in music therapy.

Future Directions

Because of the presence of multiple impairments and the unique wider context of individuals with cerebral palsy (age, other educational and therapeutic opportunities available, cultural considerations, individual interests in music), the focus of music therapy will continue to be quite varied and individualised. I have focused on active music making for the purpose of this discussion, but creative methods (such as songwriting and composition) and receptive methods and can also meet a range of needs for individuals with cerebral palsy. Use of music technology and understanding of augmentative and alternative communication will often be relevant for these interventions.

To increase the profile of music therapy as an intervention in cerebral palsy, research and clinical reports about music therapy intervention in cognitive, communication, sensory/perceptual, and behaviour areas, as well as physical areas, should refer specifically to cerebral palsy, rather than only including general descriptions such as “multiple disability.” It may be the case that research will include participants with a mixture of disabilities, but mentioning cerebral palsy specifically is still relevant. Likewise, inclusion of current classification scales will improve communication within the music therapy profession and with others interested in cerebral palsy.

Music therapists may also be well placed to provide expertise in the areas of improving engagement and participation in the wider community, including the musical life of the community, according to individual interests and aspirations. This may include assisting the development of approaches to using music technology. Like others with lifelong and sometimes severe disability, individuals with cerebral palsy and their families face developmental challenges throughout the lifespan. Current music therapy frameworks emphasizing family centred care (Shoemark, 1996), quality of life, and empowerment (Daveson, 2001) mesh well with emerging frameworks for care and development for individuals with cerebral palsy.

In addition to the usual developmental challenges, and those associated with disability, individuals with cerebral palsy often experience considerable medical intervention including multiple complex orthopedic surgeries and treatment for pneumonia and chronic lung dysfunction (subsequent to aspiration and deformities such as scoliosis). Some will be “graduates” of neonatal intensive care. There are also medical challenges posed by increased deformity for those at GMFCS levels IV and V, including pain management. Therefore, music therapists in medical settings may also be involved with these children and adults. Developing clinical and research knowledge and links between music therapists working in medical settings and those in special education is an important future direction.

Improved sharing of approaches and information between music therapists and researchers working in adult neurological music therapy and acquired brain injury in children, and those working with children with cerebral palsy would be beneficial. Although there are significant differences (the importance of addressing ordinary developmental tasks alongside those related to impairment, differences between and acquired neurological impairment following a period of normal development and a congenital neurological impairment), there are also significant similarities. Stroke in early life, for example, is a common cause of cerebral palsy. Neurologic Music Therapy already considers cerebral palsy to be within the target group of its practice, sharing significant features of other forms of neurological impairment (http://www.colostate.edu/dept/cbrm/institute.htm).

I would appreciate hearing more about music therapists’ perspectives on work with individuals with cerebral palsy and improving our profile with the wider CP community. Are the above approaches worthwhile for our profession, or should we continue to consider CP primarily in the broader area of physical and/or developmental disability?

References

Ahonen-Eerikäinen H, Lamont A & Knox R. (2008). Rehabilitation for children with cerebral palsy: Seeing through the looking glass--Enhancing participation and restoring self-image through the Virtual Music Instrument. International Journal of Psychosocial Rehabilitation. 12 (2), 41-66

Perry, M. R. (2003). Relating improvisational music therapy with severely and multiply disabled children to communication development. Journal of Music Therapy, 40 (3), 227-246.

Perry, M. R. (1999). Relating improvisational music therapy to communication development: A case study approach with severely and multiply disabled children. Unpublished master’s thesis, University of Melbourne.

Bixler, J.W. (1968). Music therapy practices for the child with cerebral palsy. In E. Thayer Gaston, Music in therapy (pp. 136-143). New York: MacMillan.

Daveson, B.A. (2001). Empowerment: an intrinsic process and consequence of music therapy practice. Australian Journal of Music Therapy, 12, 29-38.

Eliasson, A.C., Krumlinde Sundholm L, Rösblad B, Beckung E, Arner M, Öhrvall AM , Rosenbaum P. (2006). The Manual Ability Classification System (MACS) for children with cerebral palsy: scale development and evidence of validity and reliability. Developmental Medicine and Child Neurology 48, 549-554

Gorter, J.W., Rosenbaum, P. L., Hanna, S. E., Palisano, R. J., Bartlett,D. J., Russell, D. J., Walter, S. D., Raina, P., Galuppi, B. E., and Wood, E. (2004). Limb distribution, motor impairment, and functional classification of cerebral palsy. Developmental Medicine & Child Neurology, 46, 461-467

Hidecker, M. J. C., Paneth, N, Rosenbaum, P., Kent, R. D., Lillie, J., Johnson, B., & Chester, K. (2008, March). Developing the Communication Function Classification System (CFCS). Poster session presented at a Cerebral Palsy Research conference, Ann Arbor, Michigan.

Krigger, K.W. (2006). Cerebral Palsy: An overview. American Family Physician, 73 (1), 91-100. Retrieved 20 January, 2010 from www.aafp.org/afp

Kwak, E.E. (2007). Effect of auditory rhythmic stimulation of gait performance in children with spastic cerebral palsy. Journal of Music Therapy, 44 (3), 198-216.

Lem, A., Paine, G., Drummond, J. (2008). A dynamic sonification device in Creative Music Therapy. Conference Proceedings, College of the Arts, University of Western Sydney.

Palisano, R.J., Hanna, S.E., Rosenbaum, P.L., Russell, D.J., Walter, S.D., Wood, E.P., Raina, P.S., Galuppi, B. E. (2000). Validation of a model of Gross Motor Function for children with Cerebral Palsy. Physical Therapy, 80 (10), 974-985.

Rosenbaum, P. (2003). Cerebral palsy: What parents and doctors want to know. British Medical Journal, 326, 970-974. Retrieved 29 April 2005 from bmj.com.

Rosenbaum, P., Bernard, D., Leviton, A., Paneth, N., Jacobsson, B., Goldstein, M., Bax, M. (2005). The definition of cerebral palsy. Developmental Medicine and Child Neurology, 47, 571-576.

Schneider, E. (1968). Music therapy for the cerebral palsied. In E. Thayer Gaston, Music in therapy (pp. 136-143). New York: MacMillan.

Shoemark, H. (1996). Family-centred early intervention: Music therapy in the playgroup program. Australian Journal of Music Therapy, 7, 3-15.

Thoms, K. (2004, November). Low technology; necessary aids in music therapy practice with children and adolescents suffering from multiple serious impairments MusicTherapyToday Vol. V, Issue 5 November. Retrieved January 6. 2010 from http://www.musictherapyworld.net/modules/mmmagazine/showarticle.php?articletoshow=122&language=en