Date: Tue, 11 Jan 2005 06:29:06 +0000 (GMT) From: Ramesh Mishra Subject: Neurogenic Language Disorders in Children
EDITOR: Fabbro, Franco TITLE: Neurogenic Language Disorders in Children PUBLISHER: Elsevier Ltd. YEAR: 2004
Ramesh Kumar Mishra, Lecturer in Linguistics. Dept. of Speech Pathology, All India Institute of Speech and Hearing. Mysore, Karnataka, India
This volume of papers on neurogenic language disorders in children, edited by Franco Fabbro is the outcome of the International Symposium of the IALP's (International Association for Logopedics and Phoniatrics) Aphasia Committee on Neurogenic Language Disorders in Children, held in Cividale del Friuli (Udine, Italy) in 2003. There are twelve papers in all and they are self-contained with reference lists attached at the ends. Most of the papers are from authors based in European scientific establishments. The papers have not been divided into any groups. At the end of the book there are subject and author indices. Various empirical and meta-analytical research syntheses on different kinds of childhood neurogenic language disorders (acquired childhood aphasia, Landau Kleffner's Syndrome, Crossed aphasia etc) following different kinds of methodologies (radiological, behavioral, case studies) have been assembled in this volume. In spite of their diversity, they all address critical issues concerning diagnosis, prognosis and long term outcomes of childhood neurogenic language disorders in children because of acquired lesions in the brain. This is perhaps a first edited book containing all the papers exclusively on an important theme like childhood neurogenic language disorders. The book is addressed to researchers and clinicians working in the field of aphasiology and neurogenic language disorders in children and other researchers in neurolinguistics and speech language pathology.
Franco Fabbro's introductory chapter (pp. 1-7) makes a clear categorization of different childhood language disorders with neurogenic etiologies and their specific differentiating features thus making the thematic background for all following chapters. Fabbro's experience as an researcher and author in the area of language pathology and neurolinguistics reflect in the clarity of the statements he makes when he includes only a particular types of childhood language disorders of neurogenic origin in this volume. May be they are in the forefront of research (like epileptic aphasias and LKS). The author gives the basic neurological symptoms of the common neurogenic language disorders in children along with their linguistic correlates based on which they are currently diagnosed. Fabbro raises the basic debate of recovery of language abilities in children who have localized brain lesions compared to adults who have aphasia. This issue is still controversial in neurolinguistics. In the lights of new findings he says that "[in] relation to acquired childhood aphasia, recovery from adult aphasia remains one of the hotly debated issues today". Before the early 1970s language recovery in children with aphasia was believed to be rapid and complete (Lenneberg, 1967). But many of the papers in this volume show that this is not the case and children still suffer from several kinds of subtle language impairment even after recovery from medical neurological symptoms (p. 2). This theme of brain plasticity and language recovery from aphasia in children and adults again discussed in many empirical studies in this volume. Fabbro describes the genetic disorders like mental retardation, Down's syndrome, William's syndrome, Fragile X syndrome, and Turner syndrome. But none of the chapters are devoted to these disorders. In conclusion, the author makes the very pertinent remark, "each single disorder should also be studied keeping in mind the whole range of childhood language disorders" (p.6)
Chapter 2 titled, 'Pathophysiological Basis of Aphasia and Verbal Outcome in Landau-Kleffner Syndrome' (9-23) is by Marie-Noelle, Metz-Lutz and Steve Majerus. It examines the diverse nature of verbal impairment in children with LKS using ERP and PET. After providing a brief historical background of this syndrome, the authors discuss clinical features of acquired epileptic form aphasia, particularly those forms of the disorders where they show that the typical EEG recorded during wakefulness showing paroxysmal spike-wave discharges (SWDs) found in patients with LKS and the typical EEG recorded during continued spike waves discharges during slow sleep as a hallmark for the diagnosis of the disease. While discussing the typical neuropsychological deficits observed in children with LKS the authors analyze deficits in receptive language, auditory comprehension, agrammatic language output while comparing finding with other published results. A paragraph on clinical evolution of LKS includes the effect of neurological abnormalities on the changing aphasic manifestations. The authors observe that the actions of the anti-epileptic drugs on speech and language behaviour in such patients have not been understood clearly so far. Under the heading, ' Late Outcome of LKS', the authors draw n several studies to focus on the nature of expressive and receptive languages in patients with LKS after they have recovered. While discussing the pathophysiological basis of epileptic aphasia, the authors review studies that have shown metabolic evidences, neurophysiological findings and EEG patterns in age-related focal epilepsy. The last section before the discussions is devoted to the interpretation of findings from their earlier studies, which show the evidence for persistent dysfunction in the superior temporal cortex with impairment of the phonological short-term memory. Then there is the evidence of reduced glucose uptake in the brains of the patients with LKS in studies using PET. In the overall discussion section the authors advance a provisional pathophysiological accounts of aphasic disorders an late outcome of LKS and suggest a more or less direct relationship between the epileptic activity which they call inhibitory and induces phonological short-term memory and other types of verbal impairments.
Chapter 3 by Roberto Tuchman is titled 'Acquired Language Disorders and Epilepsy: From Landau-Kleffner's Syndrome to Autistic Regression' (25-35). The paper starts with a rather comprehensive survey of literature on acquirer aphasia with convulsive disorder with particular reference to LKS and then discusses the regression in speech and language in children with autism who also have epileptic form EEG. . Towards the conclusion the authors note that, ' acquired epileptic form aphasia associated with epilepsy or epileptic form abnormalities are not specific entities. The studies reviewed here suggests that they present part of a spectrum disorder with a common pathophysiology with varying severity of clinical manifestations dependent on the location and quantity of epileptic form activity (p.32). Theses discussions raise the question of the exactness of relating EEG results to clinical symptoms of a disorder for diagnosis purpose. Although the advancement of such sophisticated techniques as EEG and Magnetoencephalography have helped researchers to locate the precise locations of neurological/chemical dysfunctions, but in a clinic one sees a range of clinical symptoms which are difficult to link. This paper is not an empirical investigation but presents a review-based analysis of other research findings and offers a synthesis for looking at the disorder from r pint of view.
Chapter 4 is titled 'Persistent Subtle Language and Learning Deficits in a Child With Acquired Epileptic Form Opercular Syndrome' (37-48) is written by Paula Cipriaui, Anna M. Chilosi, Claudia Casaliui, Luria Pfanner and Giovanni Cioni. The chapter repots the findings of a three year long case study of a child with Acquired Epileptic form Opercular Syndrome (AEOS) or also known as Foix-Chavanny Marie Syndrome (FCMS) and focuses on his persistent subtle long term language and learning difficulties due to impaired phonological processing. In the introduction where the symptomatic history of AEOS is given, the authors note that, "AEOS and LKS would represent neurological disorders, sharing similar pathophysiological mechanisms in which long standing electrical dysfunctions of perisylvian neurons translates into bilateral neurological dysfunction" (p.38). The long- term fluctuations in speech and language abilities in these patients are attributed to the changing electro-chemical status of the brain when the syndrome is active and when not. Previous authors in this volume where EEG normalcy has been taken to be a condition for impairment in speech and language functions in other neurological syndromes have noted similar observations. The authors discuss clinical, neuropsychological and EEG data from 5.3 years to 6.4 years of the child on several linguistic variables to argue for their positions. The brief discussion on the long-term outcomes of the child describes his severe reading a writing impairment.
Chapter 5 by Anna Chilosi, Chiara Pecini, Paola Cipriani, Daniela Brixxolava, Paola Brovedani, Giovani Ferretti, Lueia Pfanner and Giovanni Ceoni is titled, 'Cerebral Language Lateralization and Early Linguistic Development in Children with Focal Brain Lesions' (49-63). Here the shift is from epilepsy induced neurological conditions like LKS to young children with early damage to left and right hemispheres. This paper discusses the longitudinal studies conducted on such children with a focus on their focal lesion type and early Lateralization of language in such children. The introduction reviews such concepts like 'plasticity' and 'equipotentiality' in relation to early hemispheric specialization of language (Lenneberg, 1967) and also the importance of dichotic listening paradigm to investigate such issues (Kimura, 1961, 1967). These are old and still unsolved problems in the domain of brain -language discussion. As an empirical paper, the authors provide information on subjects, MRI assessment results, electrophysiological tests, and linguistic assessments along with the results of dichotic listening. The results indicate a very early left hemisphere specialization; significant linguistic deficits in children with left side focal lesions compared to right side lesions (this has been a repeated observation in the literature) and plasticity seen with the potential for regeneration as significant language recoveries have been observed in such children. The study points out towards the long-term language outcomes in such children and their therapeutic management.
Chapter 6 is titled, 'Language Disorders Associated with Paroxysmal Abnormalities During NREM Sleep After Very Early Brain Lesions' (65-85) and is by Fabbro, Tavano, Cristofori and Borgatti. This has descriptions of several case studies. The authors provide very detailed neurological, medical and linguistic evaluations along with EEG and MRI results of subjects whom they have followed since a long time. These children have early lesions in cortical and subcortical areas and show different degrees of language impairments. Based on their EEG findings the authors argue that the presence of epileptic form abnormalities in NREM sleep is a key predictive factor for cognitive/linguistic delay in children with early brain lesions. This paper strongly consolidates the evidence that paroxysmal abnormalities in the EEG of children with or without epileptic seizures are strong clinical criteria. . This paper seems to argue that for any form of language impairments there must be a neurological basis.
Chapter 7 titled 'Language and Phonological Awareness Abilities of Children Treated for Posterior Fossa Tumor' (87-126) is by Murdoch, Docking and Ward. The paper starts with an initial discussion of the role of cerebellum in language development in general and language impairment in specific. This is a hotly argues issue in neurolinguistics today. The subjects of the study are children with posterior fossa which the authors say accounts for over half of the brain tumors occurring in children (Cohen et al, 1980). The paper investigates general language, high level language and pre-literacy skills in children following treatment for posterior fossa tumor, in the context of tumor types and their associated treatment effects. Authors provide very detailed descriptions of each subject's performance on a range of linguistic tasks to show individual differences in language abilities. The paper concludes that high-level language impairment is observed in children with posterior fossa tumors and they link the defects in such cases to abnormalities in the cerebellum. The authors argue for the children with posterior fossa tumors as a distinct clinical population with specific linguistic cognitive impairments.
Chapter 8 by Borgatti, Tavano, and Fabbro is titled 'Language Development in Children with Malformations"(127-148). Here the authors raise the question of contributions of cerebellum in language development and maintenances and how malfunctions localized to one or both cerebral hemispheres may result in permanent receptive and expressive deficits. The authors subscribe to the proposal that, although subtle and transient, language disorders following acquired focal or large cerebral lesions point towards involvement of the cerebellum in human language processing. They discuss the nature of language impairment in theses patients with different degrees of congenital cerebral malformations with extensive use of various standardized test batteries to tap memory, visuo-spatial, executive functions and language. The findings show noticeable variability in the impairment of language in its specific modules according to the age of the patient. However the paper does not claim a direct involvement of cerebellum in language acquisition or impairment but speculates on it's being fully functionally intact for smooth development of language and other cognitive abilities.
Chapter 9 by Marien, Paquier, Engelborghs and De Dayn is titled 'Crossed Aphasia in Children' (147-180). The chapter is a meta-analysis of several primary published reports on acquired childhood aphasia and crossed aphasia and also has a detailed analysis of selected cases of crossed aphasia. The treatment is quite historical and includes reviews of many nineteen-century studies on handedness, dexterity, hemispheric specialization and aphasia in childhood (e.g. Cotrad, 1897; Sach and Peterson, 1890 and Freud, 1897). Starting with the earliest articulated notions of acquired childhood aphasia, the authors examine the nature of crossed aphasia and other cases of childhood lesion language disorders through 1900 to 1978 (p.150). There is a discussion of crossed aphasia in sinistrals and dextrals. Crossed aphasia in dextrals has been very less studies in the literature. In this connection the authors rightly observe that "taken together with the extremely low incidence of CAD in children, these considerations corroborate the view that lateralized cerebral dominance for language represents an innate neurobiological condition" (p.169).
Chapter 10 by Raquier, Maldegam, Dongen and Creton is titled, 'Recognizable Spontaneous Characteristics in a Young Adult Twelve Years after She Became Aphasic as a Child' (181-197). This case study is a long-term follow up of an aphasic child focuses on several linguistic variables that continue to manifest over year as typical aphasic deficits. The analysis focuses largely on the pragmatic aspects of conversational speech in terms of comparisons between acute phase and followed up phases. The introduction reviews pertinent literature reveling the long term outcomes of linguistic and non linguistic skills in children with aphasia acquired after onset of language acquisition and states that aphasia symptoms persist till late adulthood in very subtle forms (Paquier and van Dongen, 1996; Watamori et al 1990). Very careful use of techniques in analysis of spontaneous language samples by the authors makes the picture clear and conclusions strong. The authors raise a question as per the utility of a variable like MLU (Mean Length of Utterance) in measuring outcomes in such cases arguing that, "MLU measurements performed at two different points in time in the same patient do not show significant differences despite a significant recovery, as the measurements are not indicative of the intrinsic characteristics of semantic adequacy or morph syntactic complexity and exactness" (p.191). This is a very important argument as far as methodology of spontaneous language sample analysis is concerned. At the end the authors offer a very useful appendix containing descriptions of many technical terms used in spontaneous analysis of speech. Issues argued in this paper are very important for clinicians and researchers working with aphasic patients and trying quantifying language sample for analysis.
Chapter 11 by Helena Lehelkova is tiled, 'Recovery from Aphasia After Polytrauma in a Czech Child: What is Lost and What is Left"(199-229). This is a case study of a Czech child with acquired aphasia and it describes the aphasic symptoms in the child during her re-acquisition of language and compares them with aphasic deficits in a group of selected Czech adults with aphasia. The paper addresses the very important point of continuation of aphasic symptoms over time and as age matures in an individual. The author first discusses her own past work on aphasia and agrammatism in Czech and then provides a very detailed neurological history of the patient before coming to issues like, rehabilitation strategies undertaken to improve communication skills. The author gives a comprehensive account of the linguistic analysis of the patient's samples of spontaneous speech in different time intervals. The samples that are compared are narrations and conversations. Then the paper has the patient's performance on various standardized tests of language with analysis of the wrong outputs. The analysis of her performance after one year shows difference in deficits. In her writing and drawing abilities there is variation and dissociations over time. This is evident from the pictures of actual data sheets of the patients. When the performance of this child is compared to an adult with aphasia differences on several linguistic abilities become very clear. This provides strong support to the author's claim about continuity of aphasic symptoms, their similarities and dissimilarity over time at different age group.
The last chapter of the volume by Isabel Pavao Martins is titled 'Persistent Acquired Childhood Aphasia' (231-251). The focus of the paper is on long- term outcomes of children who have suffered brain damage early in life. Authors discuss many of the aphasic symptoms, which either persist or change qualitatively as well as quantitatively over time with analyses of actual clinical data. The paper discusses clinical data of several aphasic patients having different etiology and looks at those typical aphasic symptoms that are still visible through tests even after the patient has medically recovered. One most important point made by the authors is about the age of onset of aphasia and its relation to future chance of recovery and changing plasticity of the brain, which has effect on language acquisition. The lesion related variables (site and nature, late epilepsy) but not subject-related variables (age, gender, grade of education) are the main facts responsible for the outcome of aphasic symptoms (p.244). A well argued discussion section takes up the matter of better recovery of aphasia in children than in adults. In the conclusion the authors note, "the prognosis o acquired childhood aphasia secondary to static brain lesions is generally favorable with a higher rate of recovery than in adults. Yet language recovery is less complete than that reported after congenital lesions, suggesting a reduced plasticity during the first years of life (p. 247).
This is an excellent collection of papers on a very important theme of language disorder and is going to be a valuable reference tool for students, researchers and clinicians. The collections of articles have been done with good editorial insight. They address diverse issues in neurogenic language disorders in children involving very cutting edge research methods. There are no typographical errors on any page and the book is very well produced. The articles are fairly technical in nature and the volume is addressed to professionals in the field. When majority of publications on aphasia exclusively deal with adult forms of the disorder this volume fills the gap taking up in depth studies on several kinds of neurogenic disorders that are because of early injury to the brain. Authors have taken sufficient care in clear descriptions of their methodologies that will help in replication of the findings in other languages.
The volume contains paper addressing several pertinent theoretical and methodological problems in the area of childhood neurogenic language disorders. But some of the themes are very new and the results have to be replicated in other languages to verify. Regarding the dependence of EEG measures o identify epileptic aphasia one paper's authors note: "However, the seizures and the EEG findings do not always correlate with the clinical pictures and as such the EEG and the seizures may be only epiphenomena that provided for the identification of a diverse group of language-EEG- epileptic encephalopathy with diverse etiologies" (p.32). This is a methodological question. But the papers are up to date research summaries of the field. These papers are certainly helpful to know what are the big theoretical questions in neurogenic child language disorder today.
Cohen, M. E., P. K. Duffuer and C. K. Tebbi (1982). Brain tumors in children: diagnosis and management. In Major Topics in Pediatric and Adolescent Oncology (C. K. Tebbi, ed.), pp. 240-289. G. K. Hill Medical Publishing, Boston.
Cotard, J. (1868). Etude Sur l'Atrophie Cerebrale. Faculté de Médécine, Paris.
Freud, S. (1897). Die Infantile Cerebrallmung. Alfred Holder, Wien.
Kimura, D. (1961). Cerebral dominance and the perception of verbal stimuli, Canadian J Psychology, 15, 166-71.
Kimura,D .(1967). Functional asymmetry of the brain in dichotic listening . Cortex, 3, 163-78.
Lenneberg, E.H. (1967). Biological Foundations of Language. John Wiley and Sons. New York.
Paquier, P. and H. R. Van Dongen (1996). Review of research on the clinical presentation of acquired childhood aphasia. Acta Neurol Scand, 93, 428- 436.
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Watamori, T. S, S. Ssannma and S.Ueda. (1990). Recovery and plasticity in child-onset aphasics: ultimate outcome at adulthood, Aphasiology, 4,9-30
ABOUT THE REVIEWER:
ABOUT THE REVIEWER
I am a lecturer in linguistics teaching clinical linguistics, psycholinguistics and general linguistics to undergraduate and postgraduate students of speech and hearing sciences. I have a PhD in linguistics from the University of Delhi where I worked on phonological constraints in developmental dyslexia. I also have M.Phil and MA degrees in linguistics from the same university. My research interests are in linguistic theory and language disorder, construction grammar, anaphora and morphology in aphasia.