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.
SENSORY IMPAIRMENTS
Individuals with cerebral palsy frequently exhibit sensory deficits, especially visual and tactile deficits. Some have limited visual function, for example, abnormal ocular movements and reflexes. Many have a deficient tactile sensibility, characterized by impaired two-point discrimination, inabilities to recognize and discriminate between objects by touch, and inadequate proprioceptive input.
1. Visual function in children with hemiplegia in the first years of life
The aim of this study was to evaluate the incidence of visual function abnormalities in children with infantile hemiplegia, and the relation between visual abnormalities and type of lesion, as shown by brain MRI. Visual function was tested (grating acuity, visual field size, binocular optokinetic nystagmus [OKN], and ocular movements) in a group of 47 children with congenital or early acquired hemiplegic cerebral palsy (mean age 25 months, range 8 to 52 months). The cohort was subdivided into four groups according to MRI findings: brain malformations (n=5), abnormalities of the periventricular white matter (n=20), cortical-subcortical lesions (n=16), and non-progressive postnatal brain injuries (n=6). More than 80% of the children showed abnormal results in at least one visual test: acuity was the least impaired function, while visual field and OKN were abnormal in more than 50% of the cohort. No specific correlation could be identified between the type and timing of the lesions and visual function. Unlike adults with stroke, visual field defects were not always related to contralateral damage in the optic radiations or in the visual cortex. These results indicate that visual abnormalities are common in children with hemiplegia, and that they cannot always be predicted by MRI. All children with hemiplegia need a detailed assessment of visual function.
[Guzzetta, A., Fazzi, B., Mercuri, E., Bertuccelli, B., Canapicchi, R., van Hof-van Duin, J. & Cioni, G. (2001). Visual function in children with hemiplegia in the first years of life. Developmental Medicine and Child Neurology, 43(5), 321-9.]
2. Tactile sensory abilities in cerebral palsy: Deficits in roughness and object discrimination
Motor deficits in cerebral palsy (CP) have been well documented; however, associated sensory impairment in CP remains poorly understood. We examined tactile object recognition in the hands using geometric shapes, common objects, and capital letters. Discrimination of tactile roughness was tested using paired horizontal gratings of varied groove widths passively translated across the index finger. We tested 17 individuals with hemiplegia (mean 13y 9mo [SD 5y 2mo]; 6 males, 11 females), 21 with diplegia (mean 14y 10mo [SD 7y]; 10 males, 11 females), and 21 without disabilities (mean 14y 10mo [SD 5y 1mo]; 11 males, 10 females). All participants with CP fell within level I or II of the Gross Motor Function Classification System and level I or II of the Manual Abilities Classification System. Individuals with CP were significantly less accurate compared with those without disabilities on all tactile object-recognition tasks using their non-dominant hand. Both groups of patients also had significantly higher thresholds for groove-width differences with both hands compared with those without disabilities. Within the group with diplegia, only roughness discrimination differed between hands, whereas within the group with hemiplegia, significant between-limb differences were present for all tasks. Despite mild motor deficits compared with the entire population of individuals with CP, this sample demonstrated ubiquitous tactile deficits.
[Wingert, J. R., Burton, H., Sinclair, R. J., Brunstrom, J. E. & Damiano, D. L. (2008). Tactile sensory abilities in cerebral palsy: Deficits in roughness and object discrimination. Developmental Medicine and Child Neurology, 50(11), 832-8.]
3. The determination of sensory deficits in children with hemiplegic cerebral palsy
Therapeutic intervention for children with cerebral palsy begins with accurate appraisal of abilities and disabilities. Currently, treatment focuses on the identified motor deficits, with any underlying sensory deficits often being overlooked. Sensory input is an essential component of motor function and motor control. Therefore, the objective of this study was to determine the presence and extent of sensory deficits in school-aged hemiplegic children using a formal clinical sensory battery, as well as somatosensory evoked potentials. A cross-sectional comparative study was performed comparing sensory function in hemiplegic children and healthy controls. Nine hemiplegic children and 41 healthy controls between 4 and 19 years of age were assessed. Hemiplegic children were included if they had a minimum level of receptive language function of 30 to 33 months and expressive language ability of 24 to 27 months, and no severe limitation of joint range of the hand. Significant bilateral sensory deficits (88.8%) were ascertained in hemiplegic children (P < .05), when compared to the performance of the healthy controls. Stereognosis and proprioception were the chief modalities affected bilaterally. The extent of sensory loss did not mirror the severity of motor deficit. Conversely, findings on somatosensory evoked potentials were closely related to motor function. Thus, a clinical sensory evaluation should be an integral part of the assessment of children with cerebral palsy. The likelihood of sensory impairment in one or more modalities on the hemiplegic or nonhemiplegic side is underappreciated and needs to be identified by rehabilitation specialists to maximize the functional potential of these children.
[Cooper, J., Majnemer, A., Rosenblatt, B. & Birnbaum, R. (1995). The determination of sensory deficits in children with hemiplegic cerebral palsy. Journal of Child Neurology, 10(4), 300-9.]
4. Sensibility deficiencies in the hand of children with spastic hemiplegia
We evaluated 40 children with spastic hemiplegia due to cerebral palsy for sensory function and relative limb size in the affected and unaffected upper extremities. Sensory function of each limb was evaluated with respect to stereognosis (12 objects), two-point discrimination, and proprioception. Four size measurements of each limb were made: arm and forearm circumference and forearm and forearm-hand length. This study showed that 97% of the spastic limbs had a stereognosis deficit, 90% had a two-point discrimination deficit, and 46% had a proprioception deficit. Thus sensory deficits are the rule rather than the exception in children with spastic hemiplegia. Those children with severe stereognosis deficits had significantly smaller limbs in all four measurement parameters than the children with mild or moderate stereognosis deficits. In the preoperative evaluation of children with spastic hemiplegia, severe size discrepancy is a physical examination tool that can be used as a predictor of severe sensory deficits. This information is helpful for the hand surgeon in establishing realistic surgical goals.
[Van Heest, A. E., House, J. & Putnam, M. (1993). Sensibility deficiencies in the hand of children with spastic hemiplegia. The Journal of Hand Surgery [American], 18(2), 278-81.]
5. Comparing tests of tactile sensibility: Aspects relevant to testing children with spastic hemiplegia
Children with hemiplegic cerebral palsy (OP) commonly exhibit tactile sensory deficiencies in their hands in addition to their motor problems. The aim of this study was to compare and evaluate the usefulness of some common tests of tactile sensibility for use with children with hemiplegic CP. Twenty-five children with hemiplegia aged between 5 and 18 years, and 19 control individuals participated. All children were examined with Semmes-Weinstein monofilaments, two-point discrimination (2PD), stereognosis of familiar objects, stereognosis of forms, and functional sensibility. Dexterity, spasticity, and bimanual task performance were also assessed. Results from the different sensory tests deviated greatly. We found three tests to be useful: 2PD of 3 mm spacing, which was the most sensitive test, stereognosis of familiar objects, and functional sensibility assessed through the Pick-up test (comparing performance with and without the influence of vision). Stereognosis of forms and threshold values of touch (Semmes-Weinstein monofilaments) are seemingly less useful tests for children with CNS impairments. Deficient sensibility was strongly related to dexterity. Aspects concerning the testing methodology are discussed.
[Krumlinde-Sundholm, L. & Eliasson, A. C. (2002). Comparing tests of tactile sensibility: Aspects relevant to testing children with spastic hemiplegia. Developmental Medicine and Child Neurology, 44(9), 604-12.]
6. Abnormalities of tactile sensory function in children with dystonic and diplegic cerebral palsy
Recent studies have shown the presence of sensory dysfunction in adults with focal dystonias. The authors hypothesize that children with secondary dystonia due to cerebral palsy may share a similar sensory dysfunction. To test this hypothesis, they evaluated tactile spatial discrimination threshold using Johnson, Van Boven, Phillips domes in 10 children with cerebral palsy and upper extremity dystonia, 8 children with diplegic cerebral palsy without involvement of the arms, and 21 unaffected children. Both patient groups had poor tactile discrimination compared with controls. The authors therefore conclude that children with secondary dystonia and diplegia due to cerebral palsy have deficits of tactile sensation that are similar to deficits seen in adults with focal dystonia. These results are the first to test the spatial discrimination threshold using Johnson, Van Boven, Phillips domes in children with cerebral palsy.
[Sanger, T. D. & Kukke, S. N. (2007). Abnormalities of tactile sensory function in children with dystonic and diplegic cerebral palsy. Journal of Child Neurology, 22(3), 289-93.]
7. Visual disorders in children with brain lesions: 2. Visual impairments associated with cerebral palsy
Disorders of visual function are a common finding in children with cerebral palsy. In some cases they are secondary to ophthalmologic abnormalities such as cataract or retinopathy, but more often they are due to damage of the central visual pathway. We review the literature on the prevalence and distribution of visual abnormalities in children with cerebral palsy and their relation to cognitive, motor and emotional development.
[Guzzetta, A., Mercuri, E. & Cioni, G. (2001). Visual disorders in children with brain lesions: 2. Visual impairments associated with cerebral palsy. European Journal of Paediatric Neurology, 5(3), 115-9.]
8. Behavioral responses to tactile stimuli in children with cerebral palsy
Children with cerebral palsy often have difficulty processing tactile information. Assessment of tactile processing in children with cerebral palsy frequently relies on the use of informal clinical observations, checklists, and sensory histories without established psychometric properties. It is proposed that a formal approach to the assessment of behavioral responses to tactile stimuli will provide a better understanding of the tactile processing of children with cerebral palsy. This approach also has potential to assist with the development of intervention strategies and the evaluation of progress. The purposes of this article are to review the literature on the tactile processing difficulties of children with cerebral palsy, examine the suitability of existing assessments of tactile processing for children with cerebral palsy, and provide a rationale for a new assessment tool being developed by the authors.
[Clayton, K., Fleming, J. M. & Copley, J. (2003). Behavioral responses to tactile stimuli in children with cerebral palsy. Physical & Occupational Therapy in Pediatrics, 23(1), 43-62.]
9. Comparison of tactile preferences in children with and without cerebral palsy
Fifteen normal preschool children and 15 preschool children with cerebral palsy were presented with 10 pairs of objects and asked to identify their preference for one of the objects in each of the pairs. Five objects of different textures were used. The children only handled the objects; they did not view them during testing. The children with cerebral palsy chose hard objects significantly more often than they chose soft objects; the normal children had no significant choice preferences. Eleven of the children with cerebral palsy had choice patterns significantly different from those of the normal children. The apparent preference of the children with cerebral palsy for hard objects and their avoidance of soft objects suggests that they may have decreased tactile awareness and need the greater proprioceptive input that hard objects provide. The findings of this study indicate that preschool children with cerebral palsy may be at high risk for somatosensory disorders, which could markedly affect their hand function.
[Curry, J. & Exner, C. (1988). Comparison of tactile preferences in children with and without cerebral palsy. The American Journal of Occupational Therapy, 42(6), 371-7.]
10. Sensory disorders in cerebral palsy: Two-point discrimination
Two-point discrimination (TPD) was measured on eight points of the upper extremities of 220 children with cerebral palsy aged between seven and 14 years. 46 had classical diplegia, 23 had mildly spastic diplegia (without adductor spasms), 86 had hemiplegia, 26 had generalized dyskinesia, 10 had right- and four had left-sided hemiathetosis and 25 had quadriplegia. TPD was decreased in all cases compared with normal controls: slightly more for the classical forms of diplegia and on the paretic side of those with hemiplegia, slightly less in athetoid children. This adds further evidence to the authors' previous observations that sensory disorder is an integral part of the clinical picture of cerebral palsy.
[Lesny, I., Stehlik, A., Tomasek, J., Tomankova, A. & Havlicek, I. (1993). Sensory disorders in cerebral palsy: Two-point discrimination. Developmental Medicine and Child Neurology, 35(5), 402-5.]