Testing the language of German cerebral palsy patients with right hemispheric language organization after early left hemispheric damage

The long-term negative impact of childhood stroke on language

Objectives

This study aims to investigate the long-term language outcome in children with unilateral childhood stroke in comparison to those with perinatal strokes and typically developing individuals and to explore the impact of lesion-specific modifiers.

Methods

We examined nine patients with childhood stroke, acquired between 0;2 and 16;1 years (CHILD; 3 female, median = 13.5 years, 6 left-sided), 23 patients with perinatal strokes (PERI; 11 female, median = 12.5 years, 16 left-sided), and 33 age-matched typically developing individuals (CONTROL; 15 female, median = 12.33 years). The language outcome was assessed using age-appropriate tasks of the Potsdam Illinois Test of Psycholinguistic Abilities (P-ITPA) or the Peabody Picture Vocabulary Test (PPVT). For group comparisons, study-specific language z-scores were calculated. Non-verbal intelligence was assessed using the Test of Non-verbal Intelligence (TONI-4), language lateralization with functional MRI, and lesion size with MRI-based volumetry.

Results

All four patients with childhood stroke who initially presented with aphasic symptoms recovered from aphasia. Patients with childhood stroke showed significantly lower language scores than those in the control group, but their scores were similar to those of the patients with perinatal stroke, after adjusting for general intelligence (ANCOVA, language z-score CHILD = -0.30, PERI = -0.38, CONTROL = 0.42). Among the patients with childhood stroke, none of the possible modifying factors, including lesion side, correlated significantly with the language outcome.

Conclusion

Childhood stroke, regardless of the affected hemisphere, can lead to chronic language deficits, even though affected children show a "full recovery." The rehabilitation of children and adolescents with childhood stroke should address language abilities, even after the usually quick resolution of clear aphasic symptoms.

White matter microstructure and receptive vocabulary in children with cerebral palsy: The role of interhemispheric connectivity

BACKGROUND

Communication and cognitive impairments are common impediments to participation and social functioning in children with cerebral palsy (CP). Bilateral language networks underlie the function of some high-level language-related cognitive functions.

PURPOSE

To explore the association between receptive vocabulary and white-matter microstructure in the temporal lobes and the central part of the temporo-temporal bundles in children with CP.

MATERIALS AND METHODS

37 children with spastic motor type CP (mean age 9.6 years, 25 male) underwent a receptive vocabulary test (Peabody Picture Vocabulary Test, PPVT-IV) and 3T MRI. Mean fractional anisotropy (FA) and mean diffusivity (MD) were calculated for the temporal lobes and the interhemispheric bundles traversing the splenium of the corpus callosum and the anterior commissure. Associations between microstructure and receptive vocabulary function were explored using univariable linear regression.

RESULTS

PPVT-IV scores were significantly associated with mean white matter MD in the left temporal lobe, but not the right temporal lobe. There was no association between PPVT-IV and mean white matter FA in the temporal lobes. PPVT-IV scores were not significantly associated with the laterality of these diffusion tensor metrics. Within the corpus callosum, FA, but not MD of the temporo-temporal bundles was significantly associated with the PPVT-IV scores. Within the anterior commissure no equivalent relationship between diffusion metrics and PPVT-IV was found.

CONCLUSION

Our findings add further understanding to the pathophysiological basis underlying receptive vocabulary skills in children with CP that could extend to other patients with early brain damage. This study highlights the importance of interhemispheric connections for receptive vocabulary.

Cognitive, academic, executive and psychological functioning in children with spastic motor type cerebral palsy: Influence of extent, location, and laterality of brain lesions

PURPOSE

To investigate, in spastic motor-type cerebral palsy, the association between 1) the location and extent of brain lesions and numerous psychological outcomes; 2) the laterality of brain lesions and performance of verbal-related cognitive functions.

METHODS

The semi-quantitative scale for MRI (sqMRI) was scored for 101 children with cerebral palsy. Non-verbal and verbal proxy intelligence quotients (IQ), word reading, spelling, numerical operations skills, executive functioning, and psychological adjustment were assessed. Relationships between global and regional sqMRI scores and clinical scores were examined. The best multivariable linear regression model for each outcome was identified using the Bayesian Information Criteria. Regional sqMRI scores, gross motor functioning, manual ability, and epilepsy status were considered for inclusion as covariables. Where sqMRI scores made statistically significant contributions to models of verbal-related functioning, data were reanalysed including these sqMRI scores' laterality index. Verbal-related outcomes were compared between participants with left-sided versus bilateral brain lesions.

RESULTS

Medial dorsal thalamus and parietal lobe lesions significantly accounted for poorer verbal proxy-IQ. Left-hemisphere lateralization of temporal lobe lesions was associated with poorer verbal proxy-IQ. Participants with bilateral lesions performed significantly better than those with unilateral left-sided lesions in verbal cognitive functions. Controlling for epilepsy diagnosis, participants with ventral posterior lateral thalamus lesions presented with better Behaviour Rating Inventory of Executive Function scores, although within the normal range. sqMRI scores were not significantly associated with some psychological outcomes or these only bordered on significance after accounting for relevant control variables.

CONCLUSION

The laterality of early-life lesions influences the development of verbal-related cognitive functions.

Dysarthria syndromes in children with cerebral palsy

AIM

To investigate whether dysarthria syndromes acquired in adulthood can also be observed in children with cerebral palsy (CP) and, if so, whether they align with children's CP subtypes.

METHOD

Twenty-six children with CP participated (mean age 7y 8mo [SD 1y 2mo], 5y 1mo-9y 10mo; 16 males and 10 females). Speech samples were elicited in a computer-based game and were analysed using the auditory perceptual criteria of the Bogenhausen Dysarthria Scales (BoDyS). For statistical classification, three comparison groups of adults with standard dysarthria syndromes (i.e. spastic, hyperkinetic, and ataxic) were used. Their BoDyS data were entered into a mixture discriminant analysis, with data from the comparison groups as the training sample and those from the children with CP as the test sample. Results were related to findings in a group of adults with CP.

RESULTS

Among the children with CP, most had spastic (n=14), while fewer had ataxic (n=9) or hyperkinetic (n=3), dysarthria. However, syndrome allocations were significantly more ambiguous than in adults with CP. For 11 children, their dysarthria syndromes did not align with their CP subtype.

INTERPRETATION

Dysarthria syndromes are less clear cut in children than in adults with CP because of a number of developmental factors.

WHAT THIS PAPER ADDS

Children with cerebral palsy (CP) show diverse patterns of dysarthric symptoms. Dysarthria syndromes do not seem to manifest fully during childhood. Dysarthria syndrome and CP subtype may not align in children with CP.

Language and cognitive outcomes after childhood stroke: Theoretical implications for hemispheric specialization

The purpose of this study was to investigate language and cognitive outcomes following severe childhood stroke, and the role of age at stroke according to lesion lateralization. We retrospectively included children consecutively admitted to a physical medicine and rehabilitation department between 1992 and 2015 following childhood stroke (age at stroke 1 month to15 years). Data collection included demographic and clinical information, results of cognitive assessments on the Wechsler Intelligence scales, detailed language assessments by speech and language therapists, and long-term academic outcome. Overall, 184 children (52% boys; mean age at assessment = 8.5 years, range .7-15.4 years) were hospitalized following ischemic (n = 79) or hemorrhagic (n = 105) stroke. After a median time since stroke of 4 months (n = 135), mean Full-Scale, Verbal, and Performance Intellectual Quotient (FSIQ, VIQ and PIQ) were 85 (SD = 19), 93 (SD = 22), and 85 (SD = 20), respectively. In language tests (n = 130) assessing lexical and syntactic expression and comprehension, 26%-53% of the children exhibited impairments (scores <2SD). After a median follow-up of 40 months, only 27% of the children were following a normal curriculum without adaptations or delay, and 27% were attending special education programs. School situation was strongly associated with language and FSIQ scores. Language and verbal IQ scores were significantly lower (p < .01) among patients with lesions in the left hemisphere as opposed to the right. After a left hemisphere lesion, language skills were not associated with age at stroke, but for right hemisphere lesions, language was more impaired among children who were younger at stroke onset. PIQ tended to correlate positively with age at stroke in left hemisphere lesions (poorer PIQ in early lesions) and negatively for right hemisphere lesions (poorer PIQ in late lesions). These findings, discussed in the light of the brain vulnerability and plasticity hypotheses, are in favor of a developmental view of hemispheric specialization.

[Long term outcome of perinatal stroke]

Neonatal Arterial Ischemic Stroke (NAIS) affects 6-17 newborns on 100 000-birth term neonates, most of these children keeping long-term motor and cognitive impairments. Based on a literature review, the objectives of this paper are to describe motor and cognitive outcomes after a NAIS and to propose a consensual monitoring of these children to improve their management. About 30 % of children after a NAIS will develop a unilateral cerebral palsy requiring a management by a team with expertise in physical medicine and rehabilitation. Unlike adults, especially after a left NAIS, children will not present aphasia but between 50 and 90 % will present disorders of speech and language in expression and/or reception. After NAIS, the global intellectual efficiency is usually preserved except when the size of the lesion is very important or when severe epilepsy occurs. Several studies are also in favor of vulnerability in visuospatial functions. To quantify impairments, activity limitations and participation restrictions resulting from this NAIS, early and at least yearly evaluations with reliable tools must be carried out systematically until puberty. A multidisciplinary team with a longitudinal follow-up, in all the different developmental dimensions, must conduct these evaluations in term of motor skills, cognitive impairment, behavior, autonomy, quality of life, and participation. Consequences on family functioning need to be evaluate in order to help children and family coping with this event.

Task-related fMRI in hemiplegic cerebral palsy-A systematic review

RATIONALE

Functional magnetic resonance imaging (fMRI) is used widely to study reorganization after early brain injuries. Unilateral cerebral palsy (UCP) is an appealing model for studying brain plasticity by fMRI.

AIM

To summarize the results of task-related fMRI studies in UCP in order to get better understanding of the mechanism of neuroplasticity of the developing brain and its reorganization potential and better translation of this knowledge to clinical practice.

METHODS

A systematic search was conducted on the PubMed database by keywords: "cerebral palsy", "congenital hemiparesis", "unilateral", "Magnetic resonance imaging" , "fMRI", "reorganization", and "plasticity" The exclusion criteria were as follows: case reports; reviews; studies exploring non-UCP patients; and studies with results of rehabilitation.

RESULTS

We found 7 articles investigated sensory tasks; 9 studies-motor tasks; 12 studies-speech tasks. Ipsilesional reorganization is dominant in sensory tasks (in 74/77 patients), contralesional-in only 3/77. In motor tasks, bilateral activation is found in 64/83, only contralesional-in 11/83, and only ipsilesional-8/83. Speech perception is bilateral in 35/51, only or dominantly ipsilesional (left-sided) in 8/51, and dominantly contralesional (right-sided) in 8/51. Speech production is only or dominantly contralesional (right-sided) in 88/130, bilateral-26/130, and only or dominantly ipsilesional (left-sided)-in 16/130.

DISCUSSION

The sensory system is the most "rigid" to reorganization probably due to absence of ipsilateral (contralesional) primary somatosensory representation. The motor system is more "flexible" due to ipsilateral (contralesional) motor pathways. The speech perception and production show greater flexibility resulting in more bilateral or contralateral activation.

CONCLUSIONS

The models of reorganization are variable, depending on the development and function of each neural system and the extent and timing of the damage. The plasticity patterns may guide therapeutic intervention and prognostics, thus proving the fruitiness of the translational approach in neurosciences.

Neuropsychological profiles of children with cerebral palsy

PURPOSE

To explore factors contributing to variability in cognitive functioning in children with cerebral palsy (CP).

METHOD

A geographical cohort of 70 children with CP was assessed with tests of language comprehension, visual-spatial reasoning, attention, working memory, memory, and executive functioning. Mean age was 9;9 years (range 5;1-17;7), 54.3% were girls, and 50.0% had hemiplegic, 25.7% diplegic, 12.9% quadriplegic, and 11.4% dyskinetic CP. For the participants with severe motor impairments, assessments were adapted for gaze pointing. A cognitive quotient (CQ) was computed.

RESULTS

Mean CQ was 78.5 (range 19-123). Gross motor functioning, epilepsy, and type of brain injury explained 35.5% of the variance in CQ (F = 10.643, p = .000).

CONCLUSION

Twenty-four percent had an intellectual disability, most of them were children with quadriplegic CP. Verbal comprehension and perceptual reasoning scores did only differ for the 21% with an uneven profile, of whom two-thirds had challenges with perceptual reasoning.

Lesion characteristics driving right-hemispheric language reorganization in congenital left-hemispheric brain damage

Pre- or perinatally acquired ("congenital") left-hemispheric brain lesions can be compensated for by reorganizing language into homotopic brain regions in the right hemisphere. Language comprehension may be hemispherically dissociated from language production. We investigated the lesion characteristics driving inter-hemispheric reorganization of language comprehension and language production in 19 patients (7-32years; eight females) with congenital left-hemispheric brain lesions (periventricular lesions [n=11] and middle cerebral artery infarctions [n=8]) by fMRI. 16/17 patients demonstrated reorganized language production, while 7/19 patients had reorganized language comprehension. Lesions to the insular cortex and the temporo-parietal junction (predominantly supramarginal gyrus) were significantly more common in patients in whom both, language production and comprehension were reorganized. These areas belong to the dorsal stream of the language network, participating in the auditory-motor integration of language. Our data suggest that the integrity of this stream might be crucial for a normal left-lateralized language development.

Processing verbal morphology in patients with congenital left-hemispheric brain lesions

The goal of this study was to test whether children, teenagers and adults with congenital left-hemispheric brain lesions master the regularities of German verbal inflectional morphology. Thirteen patients and 35 controls without brain damage participated in three experiments. A grammaticality judgment task, a participle inflection task and a nonce-verb inflection task revealed significant differences between patients and controls. In addition, a main effect of verb type could be observed as patients and controls made more mistakes with irregular than with regular verbs. The findings indicate that the congenitally damaged brain not only has difficulties with complex syntactic structures during language development, as reported by earlier studies, but also has persistent deficits on the morphological level. These observations suggest that the plasticity of the developing brain cannot fully compensate for congenital brain damage which affects regions associated with language functions.

Processing of non-canonical word-order: a case-series on lesion-induced reorganized language and age-effects in typical development

Complex grammatical structures are mastered late in language acquisition. We studied age-effects on performance in object topicalization in 48 typically developing German-speaking participants (aged 8-30years) and in five patients (children and adolescents) with lesion-induced atypical language representation. Production was tested by a sentence repetition task, comprehension by an acting out task. Three topicalized conditions with differing disambiguation (agreement, case, and case plus agreement) were contrasted with canonical control sentences. Children's (aged 8-13years) performance was significantly below that of adolescents and adults in all topicalized conditions. All participants made most mistakes in the agreement condition. Patients showed remarkable difficulties as compared with age-appropriate control groups in all topicalization conditions and across age-groups. Despite the small sample size, the consistency of these difficulties might hint to the importance of an intact typical neural language substrate for processing complex grammatical structures even in very early brain lesions.