REFERENCES 1. Lundkvist Josenby A, Wagner P, Jarnlo G-B, Westbom L,
3. Langerak NG, Tam N, Vaughan CL, Fieggen AG,
5. Dudley RW, Parolin M, Gagnon B, et al. Long-term
Nordmark E. Functional performance in self-care and
Schwartz MH. Gait status 17–26 years after selective
functional benefits of selective dorsal rhizotomy for
mobility after selective dorsal rhizotomy: a 10-year practice-
dorsal rhizotomy. Gait Posture 2012; 35: 244–9.
based follow-up study. Dev Med Child Neurol 2015; 57: 286–
4. Bolster EA, van Schie PE, Becher JG, van Ouwerkerk WJ,
spastic cerebral palsy. J Neurosurg Pediatr 2013; 12: 142–50.
Strijers RL, Vermeulen RJ. Long-term effect of selective
6. Hurvitz EA, Marciniak CM, Daunter AK, et al. Func-
2. Tedroff K, L€ owing K, Jacobson DN, Astr€ om E. Does
dorsal rhizotomy on gross motor function in ambulant
tional outcomes of childhood dorsal rhizotomy in adults
loss of spasticity matter? A 10-year follow-up after selec-
children with spastic bilateral cerebral palsy, compared
and adolescents with cerebral palsy. J Neurosurg Pediatr
tive dorsal rhizotomy in cerebral palsy. Dev Med Child
with reference centiles. Dev Med Child Neurol 2013; 55:
2013; 11: 380–8.
Neurol 2011; 53: 724–9.
610–6.
93.
Innovative assessment reveals speech production and language comprehension are dissociable skills in severe cerebral palsy ANGELA T MORGAN 1,2 1 Murdoch Childrens Research Institute, Melbourne, Vic.; 2 The University of Melbourne, Melbourne, Vic., Australia. doi: 10.1111/dmcn.12615 This commentary is on the original article by Geytenbeek et al. on pages 294–300 of this issue.
Cerebral palsy (CP) is a neurological disorder primarily affecting movement. In its most severe form, movement is impaired across gross motor, upper limb motor, and also speech motor systems. That is, children with Gross Motor Function Classification System levels IV to V and Manual Ability Classification System levels IV to V, typically present with impaired motor speech production abilities. Some children are dysarthric and/or verbally dyspraxic. Others have a complete absence of speech production and are referred to as ‘non-verbal’. Use of the term ‘non-verbal’ in children with severe CP often generates an assumption that these children also have severe cognitive and receptive language involvement. Yet motor speech skills are dissociable from language comprehension. Health professionals working with children with CP have frequently observed different abilities across cognition, language comprehension, and speech production. No study to date, however, has provided empirical data to reliably confirm these clinical observations. This has been partly due to our inability to accurately assess receptive language functioning in this group. Existing tests are limited in that they require speech production or fine motor (e.g. finger pointing) responses from children with severe motor disorder.1 Here we introduce the groundbreaking work of Geytenbeek et al.2 whose innovative computer-based instrument for low motor language testing (C-BiLLT), has helped confirm that at least a proportion of ‘non-speaking’ children with CP may have intact receptive communication skills. In particular, a number of children with dyskinetic CP in their
sample had relatively preserved language comprehension. Critically, this finding suggests we may be failing some children by underestimating their receptive communication abilities. The C-BiLLT is a standardized tool suitable for Dutch-speaking children. To redress this issue globally, we need further innovators dedicated to this cause to develop similar motor-adapted tools for other languages. A prognostic-based question raised by Geyteenbek et al.’s study2 is why the receptive language of children with dyskinetic CP was more preserved than in those with spastic dysarthria? Obvious risk factors for communication outcome include being born very preterm,3 the type and location of brain lesions,4 and the presence of epilepsy.5 No information was provided on brain lesions here, but indeed more children with spastic than dyskinetic CP were born very preterm and also had epilepsy. The findings of Geyteenbek et al.2 await independent replication in a larger sample, with the additional non-verbal cognitive data to be confirmatory in nature. Yet this important hypothesis-generating work heightens our awareness of these diagnostic complexities and also challenges our use of diagnostic terminology. The terms ‘non-verbal’, ‘non-speaking’, and ‘low motor language’ are used within Geytenbeek et al.’s paper.2 Each term could arguably be associated with a different meaning. The lack of agreement and interchangeable use of terms for children who are non-verbal is understandable given the assessment challenges of determining why a particular child is ‘non-verbal’; i.e. is this due to severe motor planning or programming issues (apraxia), motor execution problems (anarthria or dysarthria), higher-level receptive language impairment, more generalized cognitive involvement, or a combination of any or all of these? Hence the innovative work of Geyteenbek et al.2 is not only a further step towards diagnostic precision, but also in improving labelling of these symptoms. Looking beyond CP, much of the broader neurodevelopmental literature is rife with limCommentaries
215
ited phenotyping that fails to adequately dissociate specific speech (e.g. articulation, dysarthria, apraxia) from language (e.g. grammar, semantics, morphology, etc.) impairments. Poor phenotyping and non-specific terminology have an impact beyond the individual patient and their management; it is actually limiting scientific advancement. Poor phenotyping prevents the identification of new highly specific neurodevelopmental syndromes and gene discovery, including within CP. It is time to revolutionize our assessment of children with CP, catalyzed by innovators such as Geyteenbek et al.,2 to optimize communication outcomes
for individual children and to further our understanding of this condition as a whole. A CK N O W L E D G E M E N T S Angela Morgan is funded by a National Health and Medical Research Council (NHMRC) Career Development Award (#607315). This work is supported by the Victorian Government’s Operational Infrastructure Support Program, the NHMRC Centre of Research Excellence in Childhood Language (#1023493), and the Australian Research Council Discovery Project (DP120100285).
REFERENCES 1. Geyteenbek J, Harlaar L, Stam M, et al. Utility of lan-
explorative study on associations with motor type and
4. Himmelmann K, Lindh K, Hidecker MJ. Communica-
guage comprehension tests for unintelligible or non-
disabilities. Dev Med Child Neurol 2015; 57: 294–
tion ability in cerebral palsy: a study from the CP regis-
speaking
300.
ter of western Sweden. Eur J Paediatr Neurol 2013; 17:
children
with
cerebral
palsy:
a
systematic review. Dev Med Child Neurol 2010; 52: 267– 77. 2. Geytenbeek JJM, Vermeulen RJ, Becher JG, Oostrom KJ.
Comprehension
speaking
children
of
spoken
language
with
severe
cerebral
in palsy:
nonan
3. Reidy N, Morgan A, Thompson DK, Inder TE,
568–74.
Doyle LW, Anderson PJ. Impaired language abilities
5. Cockerill H, Elbourne D, Allen E, et al. Speech, com-
and white matter abnormalities in children born very
munication and use of augmentative communication in
preterm and/or very low birth weight. J Pediatr 2010;
young people with cerebral palsy: the SH&PE popula-
162: 719–24.
tion study. Child Care Health Dev 2014; 40: 149–57.
216 Developmental Medicine & Child Neurology 2015, 57: 209–216
Copyright of Developmental Medicine & Child Neurology is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use.
3. Langerak NG, Tam N, Vaughan CL, Fieggen AG,
5. Dudley RW, Parolin M, Gagnon B, et al. Long-term
Nordmark E. Functional performance in self-care and
Schwartz MH. Gait status 17–26 years after selective
functional benefits of selective dorsal rhizotomy for
mobility after selective dorsal rhizotomy: a 10-year practice-
dorsal rhizotomy. Gait Posture 2012; 35: 244–9.
based follow-up study. Dev Med Child Neurol 2015; 57: 286–
4. Bolster EA, van Schie PE, Becher JG, van Ouwerkerk WJ,
spastic cerebral palsy. J Neurosurg Pediatr 2013; 12: 142–50.
Strijers RL, Vermeulen RJ. Long-term effect of selective
6. Hurvitz EA, Marciniak CM, Daunter AK, et al. Func-
2. Tedroff K, L€ owing K, Jacobson DN, Astr€ om E. Does
dorsal rhizotomy on gross motor function in ambulant
tional outcomes of childhood dorsal rhizotomy in adults
loss of spasticity matter? A 10-year follow-up after selec-
children with spastic bilateral cerebral palsy, compared
and adolescents with cerebral palsy. J Neurosurg Pediatr
tive dorsal rhizotomy in cerebral palsy. Dev Med Child
with reference centiles. Dev Med Child Neurol 2013; 55:
2013; 11: 380–8.
Neurol 2011; 53: 724–9.
610–6.
93.
Innovative assessment reveals speech production and language comprehension are dissociable skills in severe cerebral palsy ANGELA T MORGAN 1,2 1 Murdoch Childrens Research Institute, Melbourne, Vic.; 2 The University of Melbourne, Melbourne, Vic., Australia. doi: 10.1111/dmcn.12615 This commentary is on the original article by Geytenbeek et al. on pages 294–300 of this issue.
Cerebral palsy (CP) is a neurological disorder primarily affecting movement. In its most severe form, movement is impaired across gross motor, upper limb motor, and also speech motor systems. That is, children with Gross Motor Function Classification System levels IV to V and Manual Ability Classification System levels IV to V, typically present with impaired motor speech production abilities. Some children are dysarthric and/or verbally dyspraxic. Others have a complete absence of speech production and are referred to as ‘non-verbal’. Use of the term ‘non-verbal’ in children with severe CP often generates an assumption that these children also have severe cognitive and receptive language involvement. Yet motor speech skills are dissociable from language comprehension. Health professionals working with children with CP have frequently observed different abilities across cognition, language comprehension, and speech production. No study to date, however, has provided empirical data to reliably confirm these clinical observations. This has been partly due to our inability to accurately assess receptive language functioning in this group. Existing tests are limited in that they require speech production or fine motor (e.g. finger pointing) responses from children with severe motor disorder.1 Here we introduce the groundbreaking work of Geytenbeek et al.2 whose innovative computer-based instrument for low motor language testing (C-BiLLT), has helped confirm that at least a proportion of ‘non-speaking’ children with CP may have intact receptive communication skills. In particular, a number of children with dyskinetic CP in their
sample had relatively preserved language comprehension. Critically, this finding suggests we may be failing some children by underestimating their receptive communication abilities. The C-BiLLT is a standardized tool suitable for Dutch-speaking children. To redress this issue globally, we need further innovators dedicated to this cause to develop similar motor-adapted tools for other languages. A prognostic-based question raised by Geyteenbek et al.’s study2 is why the receptive language of children with dyskinetic CP was more preserved than in those with spastic dysarthria? Obvious risk factors for communication outcome include being born very preterm,3 the type and location of brain lesions,4 and the presence of epilepsy.5 No information was provided on brain lesions here, but indeed more children with spastic than dyskinetic CP were born very preterm and also had epilepsy. The findings of Geyteenbek et al.2 await independent replication in a larger sample, with the additional non-verbal cognitive data to be confirmatory in nature. Yet this important hypothesis-generating work heightens our awareness of these diagnostic complexities and also challenges our use of diagnostic terminology. The terms ‘non-verbal’, ‘non-speaking’, and ‘low motor language’ are used within Geytenbeek et al.’s paper.2 Each term could arguably be associated with a different meaning. The lack of agreement and interchangeable use of terms for children who are non-verbal is understandable given the assessment challenges of determining why a particular child is ‘non-verbal’; i.e. is this due to severe motor planning or programming issues (apraxia), motor execution problems (anarthria or dysarthria), higher-level receptive language impairment, more generalized cognitive involvement, or a combination of any or all of these? Hence the innovative work of Geyteenbek et al.2 is not only a further step towards diagnostic precision, but also in improving labelling of these symptoms. Looking beyond CP, much of the broader neurodevelopmental literature is rife with limCommentaries
215
ited phenotyping that fails to adequately dissociate specific speech (e.g. articulation, dysarthria, apraxia) from language (e.g. grammar, semantics, morphology, etc.) impairments. Poor phenotyping and non-specific terminology have an impact beyond the individual patient and their management; it is actually limiting scientific advancement. Poor phenotyping prevents the identification of new highly specific neurodevelopmental syndromes and gene discovery, including within CP. It is time to revolutionize our assessment of children with CP, catalyzed by innovators such as Geyteenbek et al.,2 to optimize communication outcomes
for individual children and to further our understanding of this condition as a whole. A CK N O W L E D G E M E N T S Angela Morgan is funded by a National Health and Medical Research Council (NHMRC) Career Development Award (#607315). This work is supported by the Victorian Government’s Operational Infrastructure Support Program, the NHMRC Centre of Research Excellence in Childhood Language (#1023493), and the Australian Research Council Discovery Project (DP120100285).
REFERENCES 1. Geyteenbek J, Harlaar L, Stam M, et al. Utility of lan-
explorative study on associations with motor type and
4. Himmelmann K, Lindh K, Hidecker MJ. Communica-
guage comprehension tests for unintelligible or non-
disabilities. Dev Med Child Neurol 2015; 57: 294–
tion ability in cerebral palsy: a study from the CP regis-
speaking
300.
ter of western Sweden. Eur J Paediatr Neurol 2013; 17:
children
with
cerebral
palsy:
a
systematic review. Dev Med Child Neurol 2010; 52: 267– 77. 2. Geytenbeek JJM, Vermeulen RJ, Becher JG, Oostrom KJ.
Comprehension
speaking
children
of
spoken
language
with
severe
cerebral
in palsy:
nonan
3. Reidy N, Morgan A, Thompson DK, Inder TE,
568–74.
Doyle LW, Anderson PJ. Impaired language abilities
5. Cockerill H, Elbourne D, Allen E, et al. Speech, com-
and white matter abnormalities in children born very
munication and use of augmentative communication in
preterm and/or very low birth weight. J Pediatr 2010;
young people with cerebral palsy: the SH&PE popula-
162: 719–24.
tion study. Child Care Health Dev 2014; 40: 149–57.
216 Developmental Medicine & Child Neurology 2015, 57: 209–216
Copyright of Developmental Medicine & Child Neurology is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use.
