This article was downloaded by: [Canadian Research Knowledge Network] On: 9 July 2010 Access details: Access Details: [subscription number 783016864] Publisher Psychology Press Informa Ltd Registered in England and Wales Registered Number: 1072954 Registered office: Mortimer House, 37- 41 Mortimer Street, London W1T 3JH, UK Journal of Clinical and Experimental Neuropsychology Publication details, including instructions for authors and subscription information: http://www.informaworld.com/smpp/title~content=t713657736 Language disorders in children with central nervous system injury Maureen Dennisab a Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, Ontario, Canada b Departments of Surgery & Psychology, University of Toronto, Toronto, Ontario, Canada First published on: 30 September 2009 To cite this Article Dennis, Maureen(2010) 'Language disorders in children with central nervous system injury', Journal of Clinical and Experimental Neuropsychology, 32: 4, 417 — 432, First published on: 30 September 2009 (iFirst) To link to this Article: DOI: 10.1080/13803390903164355 URL: http://dx.doi.org/10.1080/13803390903164355 PLEASE SCROLL DOWN FOR ARTICLE Full terms and conditions of use: http://www.informaworld.com/terms-and-conditions-of-access.pdf This article may be used for research, teaching and private study purposes. 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JOURNAL OF CLINICAL AND EXPERIMENTAL NEUROPSYCHOLOGY 2010, 32 (4), 417–432 NCEN Language disorders in children with central nervous system injury Language Disorders of Childhood Maureen Dennis Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, Ontario, Canada, and Departments of Surgery & Psychology, University of Toronto, Toronto, Ontario, Canada Children with injury to the central nervous system (CNS) exhibit a variety of language disorders that have been described by members of different disciplines, in different journals, using different descriptors and taxonomies. This paper is an overview of language deficits in children with CNS injury, whether congenital or acquired after a period of normal development. It first reviews the principal CNS conditions associated with language disorders in childhood. It then describes a functional taxonomy of language, with examples of the phenomenology and neuro- biology of clinical deficits in children with CNS insults. Finally, it attempts to situate language in the broader realm of cognition and in current theoretical accounts of embodied cognition. Keywords: Language disorders; Pragmatic; Semantic; Syntactic; Motor speech; Central nervous system injury. INTRODUCTION (e.g., autism; attention deficit hyperactivity disorder, ADHD), language associated with basic sensory loss Children and adolescents identified with injury to the (e.g., deafness), or language in children with mental retar- central nervous system (CNS) exhibit a variety of dation of genetic origin (e.g., Down syndrome, Fragile X language disorders that have been described by mem- syndrome, Williams–Beuren syndrome). Although these bers of different disciplines, in different journals, using conditions are often correlated with abnormal brain different descriptors and taxonomies. This paper is an development, they are not identified by CNS injury, and overview of language deficits in children with CNS their language characteristics and intervention issues insults, whether congenital or acquired after a period of have been covered extensively in journal articles and in normal development. It first reviews the principal CNS recent handbooks (e.g., Fletcher & Miller, 2005; conditions associated with language disorders in child- Schwartz, 2008). hood. It then describes a functional taxonomy of lan- guage, with examples of the phenomenology and Downloaded By: [Canadian Research Knowledge Network] At: 14:03 9 July 2010 neurobiology of clinical deficits in children with CNS CONDITIONS ASSOCIATED WITH CHILDHOOD insults. Finally, it attempts to situate language in the LANGUAGE DISORDERS broader realm of cognition and in current theoretical accounts of embodied cognition. In children, language can be disrupted by congenital The scope of the paper is limited to language after malformations originating at various points during ges- CNS injury. It does not cover primary language tation, by birth trauma, or by brain injury acquired at a acquisition failure (specific language impairment, SLI), later point in development. The broadest distinction is language in conditions defined by abnormal behavior that between congenital and acquired language disorders. Preparation of this paper was supported in part by National Institute of Child Health and Human Development Grants P01 HD35946 and P01 HD35946–06, “Spina Bifida: Cognitive and Neurobiological Variability,” by National Institute of Neurological Diseases and Stroke Grant 2R01NS 21889–16, “Neurobehavioral Outcome of Head Injury in Children,” and by National Institutes of Health Grant 1RO1 HD04946, “Social Outcomes in Pediatric Traumatic Brain Injury.” I thank Arianna Stefanatos for assistance with manuscript preparation. Address correspondence to Maureen Dennis, Program in Neurosciences and Mental Health, Department of Psychology, The Hospital for Sick Children, 555 University Avenue, Toronto, ON, M5G 1X8, Canada (E-mail: [email protected]). © 2009 Psychology Press, an imprint of the Taylor & Francis Group, an Informa business http://www.psypress.com/jcen DOI: 10.1080/13803390903164355 418 DENNIS Congenital conditions Childhood-acquired conditions Unlike adults, children may be born with a significant Like adults, children can exhibit language disorders compromise of the brain mechanisms responsible for from injury to the central nervous system after a period language. A large number of congenital conditions affect of normal development. Childhood-acquired language language. disorder, or childhood-acquired aphasia, refers to language impairment evident after a period of normal Spina bifida meningomyelocele language acquisition that is precipitated by, or associ- ated with, an identified form of brain insult. Spina bifida meningomyelocele (SBM) is a neural tube defect associated with malformations of spine and brain. It occurs at a rate of 0.3–0.5 per 1,000 live births (from Seizure disorders postdietary fortification data), a decline over the past Seizure disorders may be associated with language 20 years widely attributed to the emphasis on dietary deficits (Williams & Sharp, 2000), and language symp- supplementations of folate acid and vitamin B (Williams, toms may be part of clinical seizures or part of ictal Rasmussen, Flores, Kirby, & Edmonds, 2005). speech automatisms. The most studied seizure disorder is The neurobiology of SBM involves structural and the Landau–Kleffner syndrome (Denes, 2008; Landau & microstructural abnormalities of the cerebellum, Kleffner, 1957), which involves acquired aphasia with midbrain, and posterior cortex; and hypoplasia and convulsive disorder and agnosia for sounds in children microstructural abnormalities of white matter tracts, who acutely or progressively lose previously acquired including the corpus callosum (Del Bigio, 1993; Dennis language (Appleton, 1995; Majerus, Van der Linden, et al., 1981; Dennis et al., 2005; Fletcher et al., 1996; Poncelet, & Metz-Lutz, 2004). Fletcher et al., 2005; Fletcher, Dennis, & Northrup, 2000; Hannay, 2000; Hasan et al., 2008). Vascular disorders Inborn errors of metabolism Vascular disorders involve interruptions to the blood Systemic metabolic disorders that result in the supply within the brain as a result of occlusion (ischemic accumulation of metabolites in the bloodstream cause stroke) or rupture (hemorrhagic stroke). Degenerative brain disruption that may include speech and language disorders like atherosclerosis are rare in children, while deficits. Some of the inborn errors of metabolism that vascular strokes associated with congenital heart disease have been shown to affect speech and language include occur in childhood (Ozanne & Murdoch, 1990), from an phenylketonuria (an absence of the enzyme phenyla- embolism from the heart, complications of heart surgery, lanine), galactosemia (an inability to utilize the sugars or hypoperfusion from prolonged hypotension, or from galactose and lactose because of disordered carbohy- sickle cell disease (Ris & Grueneich, 2000). The neurobi- drate metabolism), Wilson disease (a progressive degen- ology of childhood strokes is variable. Many childhood erative disorder of the brain and liver resulting from strokes are secondary to intracranial occlusive disease in inability to process dietary copper), Sanfilippo syndrome the basal ganglia, although cortical vascular lesions in (an autosomal recessive enzyme deficiency; Valstar, the left temporoparietal lobe that produce aphasia occur Ruijter, van Diggelen, Poorthuis, & Wijburg,