Architecture of Human Language from the Perspective of a Case of Childhood Aphasia — Landau–Kleffner Syndrome (original) (raw)
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2017
This paper aims to re-evaluate the legacy of Eric Lenneberg’s monumental Biological Foundations of Language, with special reference to his biolinguistic framework and view on (child) aphasiology. The argument draws from the following concepts from Lenneberg’s work: (i) language (latent struc- ture vs. realized structure) as independent of externalization; (ii) resonance theory; (iii) brain rhythmicity; and (iv) aphasia as temporal dysfunction. Specifically, it will be demonstrated that Lenneberg’s original version of the critical period hypothesis and his child aphasiology lend themselves to elucidating a child aphasia of epileptic origin called Landau-Kleffner syndrome (LKS), thereby opening a possible hope for recovery from the disease. Moreover, it will be claimed that, to the extent that the language disorder in LKS can be couched in these terms, it can serve as strong “liv- ing” evidence in support of Lenneberg’s critical period hypothesis and his view on child aphasiology.
A correlated fluctuation of language and EEG abnormalities in a case of the Landau-Kleffner syndrome
Brain and Development, 1994
Despite growing interest in the Landau-Kleffner syndrome there have been few reports dealing with language disorders in recent years. The authors present a clinical case of a child with Landau-Kleffner syndrome focusing particulary on the relationship between language disorders and electroencephalographic abnormalities. The authors emphasize that the language disorders primarily affect the receptive sphere and that there seems to be a relationship between abnormalities during sleep with a deterioration in verbal comprehension.
Clinical Neurophysiology, 2006
Objective: To assess the linguistic abilities of a boy having Landau-Kleffner Syndrome, and relate the focal disturbance of brain activity due to epilepsy to the cognitive and linguistic deficits. Methods: Several kinds of assessments were carried out, including epileptic source analysis using electronic source localization methods and PET, neuropsychological assessment of cognitive functions, and assessment of speech perception skills (discrimination of phonetic and stress cues) using ERPs. Results: The source of epileptic activity was localized in the left superior temporal lobe. The neuropsychological assessment showed dissociation between verbal and nonverbal functions, and the performance in former was bellow the normal range. ERPs obtained to the processing of phonetic and stress speech cues indicated that the two cues were processed asymmetrically: the mismatch negativity component (MMN) was obtained for the phoneme difference, but not for the stress pattern difference. Conclusions: Our data converged as it showed that the patient presented a selective impairment of the language system, and the verbal working memory system appeared to be especially defective. It is suggested that the language deficit is at least partly due to the focal disturbance of those neural networks that underlie the functioning of the working memory system. Significance: LKS is a childhood language disorder that might serve as a model in studying what happens to the language system if, in the course of development, the essential neural circuits are severely disturbed.
Acquired epileptiform aphasia (AEA) is characterized by deterioration in language in childhood associated with seizures or epileptiform electroencephalographic abnormalities. Despite an extensive literature, discrepancies and contradictions surround its definition and nosological boundaries. This paper reviews current conceptions of AEA and highlights variations in the aphasic disturbance, age of onset, epileptiform EEG abnormalities, temporal course, and long-term outcome. We suggest that AEA, rather than being a discrete entity, is comprised of multiple variants that have in common the features of language regression and epileptiform changes on EEG. Viewed this way, we argue that AEA can be conceptualized on a spectrum with other epileptiform neurocognitive disorders that may share pathophysiological features. The implications of this viewpoint are discussed, with emphasis on parallels between the AEA variants and regressive autistic spectrum disorders.
Language regression in childhood
Pediatric Neurology, 2001
Language regression is observed both in autistic regression and as part of acquired epileptic aphasia (Landau-Kleffner Syndrome). We prospectively identified 177 children with language regression at four major medical centers, and their clinical characteristics were recorded. Their mean age at regression was 22.8 months. The mean time-to-specialist referral was 38 months of age. Most children (88%) met criteria for autism or manifested autistic features. Males (P ؍ 0.02) and children less than 3 years of age who regressed (P ؍ 0.016) had a higher probability of developing autistic behaviors. Seizures were more common in children who regressed after they reached 3 years of age (P < 0.001), and children with seizures were less likely to have associated autistic regression (P < 0.001). Electroencephalogram abnormalities were reported in 37% of patients and were more common in children with seizures (P < 0.001). At last follow-up, language function was impaired in 88% of the children, although some improvement was noted in 57%. We conclude that the loss of previously acquired language at any age, even if that language only includes a few words or communicative gestures, is often associated with a more global regression in cognition and/or behavior and has serious implications for future function. Early identification and referral of these children is necessary to allow for diagnosis and intervention.
Landau–Kleffner syndrome: a rare childhood epileptic aphasia
Journal of Neurolinguistics, 1999
Landau±Klener Syndrome (LKS), a rare epileptic aphasia which occurs at a crucial period for the development of verbal skills, arouses interest and controversy among both clinicians and neuroscientists interested in the development of language. On the one hand, the relationship between epilepsy and aphasia and the poor outcome of epileptic aphasia compared to lesional childhood aphasia is a matter of debate among the clinicians. On the other hand, the severe verbal agnosia experienced during the active period of epilepsy allows one to examine the eect of deprivation of verbal auditory input on further language development. The chronic language impairments observed in most cases following the complete recovery from epilepsy could be either a consequence of a permanent neurophysiological dysfunction (the epileptic focus) during a crucial period of functional dierentiation in the brain tissue assigned to language processing (the left superior temporal cortex), or a consequence of a lack of auditory-verbal experience.
Long-term course of Landau-Kleffner syndrome: visuo-semantic and auditory aspects of comprehension
Introduction. Landau-Kleffner Syndrome is characterized by normal speech acquisition followed by epileptic seizures, receptive and expressive language deterioration coupled with agnosia for non-verbal sounds, having variable long-term evolution. Case Report. It is described neurophysiologic and acoustic findings in a patient with Landau-Kleffner Syndrome, and correlate these with the results of a language evaluation carried out 7 years after the acute phase. It is performed Electroencephalography, Immitance Measurements, Basic Audiometry, Auditory Brainstem Response, Middle Latency Response, and P300. Language was evaluated by Boston Diagnostic Aphasia Examination. Electroencephalography was normal and audiologic evaluation revealed normal Immitance Measurements, Basic Audiometry and Auditory Brainstem Response values. An electrode effect was present in the left hemisphere in Middle Latency Response, and bilateral P300 latencies delayed on the right. Language evaluation showed severe receptive and expressive impairment, severe phonemic substitutions, which had an impact on social and academic levels. There were contextual and gestual non-verbal compensations, evidencing intellectual and cognitive domain preservation. Conclusion. This case illustrates the specific cerebral areas that can be damaged in patients with Landau-Kleffner Syndrome and which are demonstrable by clinical evaluation and proper neurophysiology studies, showing the importance of neurological, audiological, electrophysiological and language exams in a longitudinal follow up.