Cerebral palsy, a neurological disease of the young developing brain, is accompanied by a plethora of side effects. As an extension of general poverty of motor control, those with cerebral palsy show deficient hand function. Patients also present with various cognitive deficits, including reduced intellectual ability, and linguistic deficits, such as impaired language comprehension. There are concomitant sensory deficits, especially concerning tactile sensibility. Additionally, people with cerebral palsy often have impairments related to oral processes, such as swallowing. Other comorbid conditions include mental retardation and epilepsy.
Cognitive / Linguistic Impairments
Cerebral palsy is often accompanied by cognitive and linguistic impairments. Sometimes problems with motor control prevent patients from demonstrating their cognitive skills. However, children with the disease consistently evidence lower IQs than normally developing children, and a minority of people with cerebral palsy suffers mental retardation. Other cognitive deficits of cerebral palsy patients include impaired visuoperceptual and visuospatial skills, impaired memory, and trouble carrying out executive tasks. People with cerebral palsy also tend to have linguistic impairments. Due to physical constraints, cerebral palsy patients often experience difficulty speaking clearly, and many children with the disease have limited phonological awareness; as a result, some have trouble with reading, spelling and language comprehension.
1. Cerebral palsy--an increasing contributor to severe mental retardation?
It is estimated that the prevalence of nongenetic SMR associated with cerebral palsy has risen from 0.7 to about 0.9 per 1000 live births in the last decade. This is due to the predicted rise in total cerebral palsy prevalence to 2.5/1000 live births. This predicted prevalence of cerebral palsy is similar to that given for Western Australia in 1979-82, allowing for postnatal causes, but is higher than prevalence data from England and Sweden for that period. The estimated rise is due largely to improved survival and increased proportion of low birthweight babies since 1983 and also reflects the use of prevalence rates based on Mersey data. Improvements in prenatal diagnosis, and a parental choice of selective termination may lead to reductions in other causes of SMR, such as Down's syndrome and neural tube defects, so it seems that children both physically and mentally handicapped due to brain damage will contribute a greater proportion of the SMR population. The careload of these children is greater than that associated with many other causes of SMR and most survive into adult life. The implications for planning future services will need to be recognised.
[Nicholson, A. & Alberman, E. (1992). Cerebral palsy--an increasing contributor to severe mental retardation? Archives of Disease in Childhood, 67(8), 1050-5.]
2. Neuropsychologic impairment in bilateral cerebral palsy
The lower-than-average cognitive performance of individuals with bilateral cerebral palsy found in previous studies does not always refer to an abnormal performance or clinically significant impairment. We aimed to establish the percentage of persons with bilateral cerebral palsy who present neuropsychologic impairment, and its relationship to perinatal data and motor signs. Forty children, adolescents, and adults (age range, 6-38 years; 15 females and 25 males) with bilateral cerebral palsy were neuropsychologically assessed. Vocabulary was impaired in 85% of participants, language comprehension in 13-48%, visuoperceptual abilities in 60%, visuospatial abilities in 90%, short-term memory in 21-58%, declarative memory in 47-67%, and praxis comprehension in 20%, with executive deficits in 58-74%. Perinatal data (intrauterine growth and birth weight) contributed to explaining memory impairment. Among cerebral palsy subtypes (spastic, mixed, and dyskinetic), forms of impairment differed only in short-term verbal memory. No persons with dyskinetic cerebral palsy experienced impairment in immediate memory or working visual memory. We conclude that visuospatial deficit is the most frequent impairment in people with bilateral cerebral palsy. Moreover, short-term memory impairment seems sensitive to perinatal complications, and differs among bilateral cerebral palsy subtypes.
[Pueyo, R., Junque, C., Vendrell, P., Narberhaus, A. & Segarra, D. (2009). Neuropsychologic impairment in bilateral cerebral palsy. Pediatric Neurology, 40(1), 19-26.]
3. Raven’s Coloured Progressive Matrices as a measure of cognitive functioning in cerebral palsy
BACKGROUND: Cognitive dysfunction is frequent in Cerebral Palsy (CP). CP motor impairment and associated speech deficits often hinder cognitive assessment, with the result being that not all CP studies consider cognitive dysfunction. Raven's Coloured Progressive Matrices is a simple, rapid test which can be used in persons with severe motor impairment and speech limitations. We studied whether this test can offer a reliable measure of cognitive functioning in CP. METHOD: Visuoperceptual, language, memory and frontal lobe functions were evaluated in 30 participants with severe motor impaired CP and a variety of speech difficulties. The relationship between Raven's Coloured Progressive Matrices and a variety of tests was analysed. RESULTS: Raven's Coloured Progressive Matrices performance was associated with visuoperceptual, language, visual and verbal memory but not with frontal functions. Receptive vocabulary and visuospatial measures were the best predictors of Raven's Coloured Progressive Matrices raw scores. CONCLUSIONS: Raven's Coloured Progressive Matrices is a fast, easy-to-administer test able to obtain a measure related with linguistic, visuoperceptual, and memory cognitive functioning in persons with CP despite their motor and speech disorders.
[Pueyo, R., Junque, C., Vendrell, P., Narberhaus, A. & Segarra, D. (2008). Raven’s Coloured Progressive Matrices as a measure of cognitive functioning in cerebral palsy. Journal of Intellectual Disability Research: JIDR, 52(Pt. 5), 437-45.]
4. The impact of art therapy on the intelligibility of speech in children with cerebral palsy
Background. Children with cerebral palsy (CP) frequently have dysarthria, which reduces the intelligibility of their speech and can seriously impede their psycho-social adjustment. Traditional "bottom-up" rehabilitation oriented directly on the articulatory apparatus is not always successful in helping these children to speak intelligibly. The authors have developed a program of art therapy with elements of logopedic therapy to model and stimulate perception and expression, including linguistic performance, which has proven in clinical to be a helpful "top-down" approach to helping these children to speak more early.<br /> Material and methods. Out of the population of CP children treated in the Cracow Rehabilitation Center's Art Therapy Workshop in the period 1994-2001, we identified 14 children, 9 boys and 5 girls, average age 15,3, who showed severe dysarthria at admission without other language or cognitive disturbances. Our retrospective study was based on recorder results from the Auditory Dysarthria Scale and standard neuropsychological tests for fluency of speech, administered routinely once each month during the 4-month art therapy program.<br /> Results. All the children in the study group showed some degree of improvement after art therapy in all tested parameters. On the Auditory Dysarthria Scale, the largest improvements were noted in overall intelligibility (p < 0,0001); less improvement, though still statistically significant (p < 0,001) took place in respect to volume, tempo, and control of pauses. The least improvement was noted in the pronunciation of vowels and consonants (the most purely motor of the measured parameters). All the children also exhibited significant improvement in fluency of speech.<br /> Conclusions. Art therapy with elements of logopedic therapy improves the ability of children with cerebral palsy to engage in purposeful behavior, including speech and language functions, especially intelligibility.
[Pachalska, M., Franczuk, B., Macqueen, B. D., Jastrzebowska, G., Perzanowski, Z. & Neldon, K. (2001). The impact of art therapy on the intelligibility of speech in children with cerebral palsy. Ortopedia, Traumatologia, Rehabilitacja, 3(4), 508-18.]
5. Cognitive profile in young Icelandic children with cerebral palsy
We describe the cognitive profile in a complete national cohort of children with cerebral palsy (CP). One hundred and twenty-seven Icelandic children (67 females, 60 males) with CP, born between 1985 and 2000 and assessed between the ages of 4 and 6 years 6 months (mean age 5y 5mo, SD 6mo), were included in the study. IQ was measured using the Wechsler Preschool and Primary Scale of Intelligence (WPPSI) and developmental quotient (DQ) was obtained using various developmental scales. Physiological classification of CP in the children was: spasticity, n=104 (82%); dyskinesia, n=14 (11%); ataxia, n=six (4.7%), and unclassified CP, n=3 (2.3%). Spastic diplegia was the most prevalent subtype (35%) followed by hemiplegia and quadriplegia. Forty-five per cent of the group were at Level I of the Gross Motor Function Classification System, 32% were at Levels II and III, and 23% were at Levels IV and V. Sixty per cent of the children had an IQ or DQ >70. Median scores on the WPPSI were Full-scale IQ 84, Verbal IQ (VIQ) 92, and Performance IQ (PIQ) 77. Children with spastic diplegia and quadriplegia had a significantly lower PIQ than VIQ. Of the children who failed to complete the WPPSI, 20% had DQ >85. Thus, cognitive skills can be masked by limitations of movement and motor control in children with CP.
[Sigurdardottir, S., Eiriksdottir, A., Gunnarsdottir, E., Meintema, M., Arnadottir, U. & Vik, T. (2008). Cognitive profile in young Icelandic children with cerebral palsy. Developmental Medicine and Child Neurology, 50(5), 357-62.]
6. Language and motor speech skills in children with cerebral palsy
The aim of the study was to investigate associations between the severity of motor limitations, cognitive difficulties, language and motor speech problems in children with cerebral palsy. Also, the predictive power of neonatal cranial ultrasound findings on later outcome was investigated. For this purpose, 36 children (age range 1 year 10 months to 9 years 0 months) with cerebral palsy due to premature birth and white-matter damage (periventricular leukomalacia) participated in the study. Twenty-two children (62%) had an intelligence level above 70. One-half of this group exhibited motor speech problems. Children with an intelligence level below 70 (n=14, 38%) showed problems in motor speech skills as well as in verbal expressive and comprehensive skills. Neonatal cranial ultrasonography findings were moderately associated with the severity of functional motor limitations. LEARNING OUTCOMES: Readers will be able to: (1) describe different hypotheses regarding the relationship between language, speech, intelligence level and severity of cerebral palsy, (2) discuss how intelligence and functional motor limitations impact language and speech performance for children with cerebral palsy and (3) discuss the predictability of the ultrasound methodology.
[Pirila, S., van der Meere, J., Pentikainen, T., Ruusu-Niemi, P., Korpela, R., Kilpinen, J. & Nieminen, P. (2007). Language and motor speech skills in children with cerebral palsy. Journal of Communication Disorders, 40(2), 116-28.]
7. Cognitive and neuropsychological functioning in children with cerebral palsy
This article reviews the extant literature on intellectual functioning in different subtypes of cerebral palsy. Following a definition of the characteristics of each of three major cerebral palsy groups, typical neurologic and magnetic resonance imaging findings are reported. More recent studies that examine the intellectual and neuropsychological functioning of children within these classification groups are also reviewed. This review concludes that there remains a significant lack of precise information about the impact of cerebral palsy on the intellectual, motor, and neuropsychological functioning of children and that neuropsychological assessment can provide the necessary tools for such studies.
[Fennell, E. B. & Dikel, T. N. (2001). Cognitive and neuropsychological functioning in children with cerebral palsy. Journal of Child Neurology, 16(1), 58-63.]
8. Foundations of phonological awareness in pre-school children with cerebral palsy: The impact of intellectual disability
BACKGROUND: Children with cerebral palsy (CP) and accompanying disabilities are prone to reading difficulties. The aim of the present study was to examine the foundations of phonological awareness in pre-school children with CP in comparison with a normally developing control group. Rhyme perception was regarded as an early indicator of phonological awareness, whereas non-verbal reasoning, speech ability, auditory perception, auditory short-term memory and vocabulary were regarded as foundation measures. METHODS: A number of tasks were administrated to examine group differences in rhyme perception and its foundation measures. Correlations between the tasks were analysed for both groups followed by multiple regression analyses wherein rhyme perception was predicted by its foundation measures. RESULTS: Children with CP scored below their normally developing peers on emergent phonological awareness and its foundation measures. Regarding the prediction of phonological awareness, non-verbal reasoning followed by pseudoword articulation, were found to predict phonological awareness, i.e. rhyme perception, in the group of children with CP. In the control group, auditory perception was a significant predictor of emergent phonological awareness. The CP group was further split up into two groups according to the children's non-verbal reasoning skills, i.e. general IQ. The below-average IQ group scored below the average IQ group on phonological awareness and on most foundation measures. In addition, the average IQ group of the children with CP scored lower than the control group. CONCLUSION: The results of this study indicate that general intelligence and speech ability (i.e. pseudoword articulation) can be seen as important facilitators of emergent phonological awareness in children with CP. These findings support the role of intelligence in the emergence of phonological awareness in children with CP. Children with CP with intellectual disabilities seem to have a disadvantage in acquiring phonological awareness, especially when their speech abilities are also impaired. However, general intelligence is not enough to predict phonological awareness as other foundation measures are also important for phonological awareness independent of general intelligence.
[Peeters, M., Verhoeven, L., van Balkom, H. & de Moor, J. (2008). Foundations of phonological awareness in pre-school children with cerebral palsy: The impact of intellectual disability. Journal of Intellectual Disability Research: JIDR, 52(Pt. 1), 68-78.]
9. Reading and spelling abilities in children with severe speech impairments and cerebral palsy at 6, 9, and 12 years of age in relation to cognitive development: A longitudinal study
Development of literacy skills was studied in six children (one male, five females) with severe speech impairments and cerebral palsy (CP). These skills were related to intellectual development, phonological abilities, and short-term memory. Three of the children were diagnosed with dystonia, and three with diplegia. They had no, or severely restricted, independent mobility (Gross Motor Function Classification System Level IV for four children and Level V for two), and severe fine motor problems, including difficulty with pointing. As they had no intelligible speech, the Bliss system was the primary communication mode. Assessments were made at approximately 6, 9, and 12 years of age. The results revealed that the children had difficulties acquiring literacy skills, although intellectual level and phonological ability predicted otherwise. Positive development during the first 3 years was followed by an arrest. A conspicuous decrease in IQ points was also found. Thus, phonological ability does not seem to have the same predictive power for literacy development in children with severe speech impairments and CP as in typically developing children. Further studies are needed to clarify the role of phonological abilities, working memory, and strategies used in literacy acquisition in these children. Such studies might also clarify the importance of articulatory abilities in early literacy acquisition.
[Dahlgren, S. A. (2006). Reading and spelling abilities in children with severe speech impairments and cerebral palsy at 6, 9, and 12 years of age in relation to cognitive development: A longitudinal study. Developmental Medicine and Child Neurology, 48(8), 629-34.]
10. The phonological awareness abilities of children with cerebral palsy who do not speak
To investigate the importance of the connection between being able to speak and the emergence of phonological awareness abilities, the performance of children with cerebral palsy (five speakers and six non-speakers) was assessed at syllable, onset-rime, and phoneme levels. The children were matched with control groups of children for non-verbal intelligence. No group differences were found for the identification of syllables, reading non-words, or judging spoken rhyme. The children with cerebral palsy who could speak, however, performed better than the children with cerebral palsy who could not speak and the control group of children without disabilities, judging written words for rhyme. The children with cerebral palsy who could not speak performed poorly in comparison to those who could speak (but not the control group of children) when segmenting syllables and on the phoneme manipulation task. The findings suggest that non-speaking children with cerebral palsy have phonological awareness performance that varies according to the mental processing demands of the task. The ability to speak facilitates performance when phonological awareness tasks (written rhyme judgment, syllable segmentation, and phoneme manipulation) require the use of an articulatory loop.
[Card, R. & Dodd, B. (2006). The phonological awareness abilities of children with cerebral palsy who do not speak. Augmentative and Alternative Communication , 22(3), 149-59.]
11. Importance of speech production for phonological awareness and word decoding: The case of children with cerebral palsy
The goal of this longitudinal study was to investigate the precursors of early reading development in 52 children with cerebral palsy at kindergarten level in comparison to 65 children without disabilities. Word Decoding was measured to investigate early reading skills, while Phonological Awareness, Phonological Short-term Memory (STM), Speech Perception, Speech Production and Nonverbal Reasoning were considered reading precursors. Children with cerebral palsy lag behind on all reading precursors at the beginning of the second year of kindergarten. For the children without disabilities, early reading skills in Grade 1 were best predicted by Phonological Awareness and Phonological STM while Speech Production was the most important predictor of early reading success for the children with cerebral palsy, followed by Phonological Awareness and Speech Perception. Furthermore, for children with cerebral palsy, Speech Production appears to dominate reading development, as Speech Production measured at the beginning of the second year of kindergarten was strongly predictive of all other reading precursors measured at the end of the second year of kindergarten. The results of this study reveal that children with cerebral palsy with additional speech impairments are at risk for limited literacy development. Clinical implications are discussed.
[Peeters, M., Verhoeven, L., de Moor, J. & van Balkom, H. (2008). Importance of speech production for phonological awareness and word decoding: The case of children with cerebral palsy. Research in Developmental Disabilities [epublication ahead of print].]
12. Effects of speech stimuli and dysarthria severity on intelligibility scores and listener confidence ratings for speakers with cerebral palsy
This study examined differences among transcription intelligibility scores and listener confidence ratings for three different types of speech stimuli--single words, unrelated sentences, and sentences forming a narrative--all produced by speakers with dysarthria. Twelve speakers with dysarthria of varying severity secondary to cerebral palsy and 144 listeners participated in this study. Results showed that both intelligibility scores and confidence ratings were differentially affected by both stimuli and severity. For speakers with mild, moderate, and severe dysarthria, intelligibility scores were higher for narratives than for either of the other two types of speech stimuli. For speakers with mild dysarthria, sentences were substantially more intelligible than single words. However, for speakers with moderate, severe, and profound dysarthria, the difference in intelligibility scores for sentences and single words was small or nonsignificant. Confidence ratings did not follow the same pattern as intelligibility data, suggesting a mismatch between listeners' perception of their performance and their actual performance on intelligibility tasks. Copyright 2007 S. Karger AG, Basel.
[Hustad, K. C. (2007). Effects of speech stimuli and dysarthria severity on intelligibility scores and listener confidence ratings for speakers with cerebral palsy. Folia Phoniatrica et Logopaedica, 59(6), 306-17.]
13. The effect of cerebral palsy on arithmetic accuracy is mediated by working memory, intelligence, early numeracy, and instruction time
The development of addition and subtraction accuracy was assessed in first graders with cerebral palsy (CP) in both mainstream (16) and special education (41) and a control group of first graders in mainstream education (16). The control group out-performed the CP groups in addition and subtraction accuracy and this difference could not be fully explained by differences in intelligence. Both CP groups showed evidence of working memory deficits. The three groups exhibited different developmental patterns in the area of early numeracy skills. Children with CP in special education were found to receive less arithmetic instruction and instruction time was positively related to arithmetic accuracy. Structural equation modeling revealed that the effect of CP on arithmetic accuracy is mediated by intelligence, working memory, early numeracy, and instruction time.
[Jenks, K. M., de Moor, J., van Lieshout, E. C., Maathuis, K. G., Keus, I. & Gorter, J. W. (2007). The effect of cerebral palsy on arithmetic accuracy is mediated by working memory, intelligence, early numeracy, and instruction time. Developmental Neuropsychology, 32(3), 861-79.]
14. Preferred communication modes: Prelinguistic and linguistic communication in non-speaking preschool children with cerebral palsy
Seven non-speaking preschool children with severe cerebral palsy, 5-7 years of age, were studied with respect to the amount of prelinguistic versus linguistic modes of communication used in communicative interaction with a previously unknown adult. An attempt was also made to analyse this in relation to the childrens' physical, cognitive and linguistic capacities. No significant correlations were found, however. Given that all participants had reached preschool age and were of normal intelligence, the amount of linguistic communication used (12%) was much less than could be expected. Explanations for the results were suggested, including limited interaction possibilities with the environment due to motor dysfunction, which in turn might prevent development of linguistic skills necessary to take part in more complex communicative interaction later in life.
[Falkman, K. W., Sandberg, A. D. & Hjelmquist, E. (2002). Preferred communication modes: Prelinguistic and linguistic communication in non-speaking preschool children with cerebral palsy. International Journal of Language & Communication Disorders, 37(1), 59-68.]
15. Intellectual status of children with cerebral palsy after elementary education
Using Wechsler Intelligence Tests, we compared the intellectual status of children with cerebral palsy (CP) immediately before and 2 years after entering school. Verbal and performance IQs could be assessed for 23 children with spastic diplegia but only verbal IQs in six children with spastic quadriplegia. Performance IQs were much lower than verbal IQs in both the Wechsler Preschool and Primary Scale of Intelligence (WPPSI) and the Wechsler Intelligence Scale for Children-Revised (WISC-R) in children with spastic diplegia. After schooling, verbal IQ was significantly increased but there was no change in performance IQ, thus, the difference between these IQs became more pronounced. When comparing the school class types, the verbal IQs of children studying in ordinary classes became statistically higher than those of children in special classes. In contrast, since the increases in mean performance IQs were greater in children in special classes, the differences between these IQs became more pronounced in children studying in ordinary classes. We also found that although verbal IQs were lower for quadriplegic children than for diplegic children at preschool age, there was no difference after 2 years of schooling. These results underline the importance and benefits of appropriate education for children with CP.
[Ito, J., Araki, A., Tanaka, H., Tasaki, T. & Cho, K. (1997). Intellectual status of children with cerebral palsy after elementary education. Pediatric Rehabilitation, 1(4), 199-206.]