11/74. Longitudinal outcome of verbal discourse in children with traumatic brain injury: three-year follow-up.PURPOSE: This study compared changes in discourse ability between two groups of children age 5 to 10 years after brain injury: those with severe traumatic brain injury (TBI) and those with mild/moderate injury over 3-year follow-up testing. MATERIALS AND methods: Forty-three children with TBI were recruited from a larger research project examining cognitive and linguistic recovery after injury. Twenty-two of these patients had severe injuries and 21 sustained mild/moderate injuries. All children were presented an ordered sequence of pictures and asked to verbally produce a story/narrative discourse. Each child was then asked to produce a lesson relating to the story. RESULTS: The severe group performed significantly worse than the mild/moderate group when performance across all four discourse domains was considered. Both groups improved across time on selected discourse measures. Qualitative analysis suggested that the severe group showed differential rates of improvement across the individual discourse variables over the 3-year interval. CONCLUSIONS: Severe TBI can have a pernicious effect on discourse abilities in children years after injury compared with children with mild/moderate injuries. The major caveat is that the discourse measures must be sufficiently challenging when used to assess older children and children with milder forms of TBI.- - - - - - - - - - ranking = 1keywords = traumatic brain injury, brain injury, traumatic brain, brain, injury (Clic here for more details about this article) |
12/74. Crossed nonaphasia in a dextral with left hemispheric lesions: a functional magnetic resonance imaging study of mirrored brain organization.BACKGROUND: General conclusions concerning mechanisms of cerebral lateralization may be learned from the investigation of functional brain organization in patients with anomalous lateralization. CASE DESCRIPTION: The functional organization of language, attention, and motor performance was investigated in a 42-year-old patient with crossed nonaphasia by means of functional MRI. The strongly right-handed man experienced a left middle cerebral artery infarction documented by MRI without exhibition of aphasia. However, the left hemispheric stroke was accompanied by visuospatial impairment, right-sided slight sensory and motor paresis, and right homonymous hemianopia. No history of familial sinistrality or prior neurological illness was present. Functional MR language mapping revealed strong right hemispheric activation in inferior frontal and superior temporal cortices. Finger tapping with the right hand recruited ipsilateral premotor and motor areas as well as supplementary motor cortex. A Stroop task, usually strongly associated with left-sided inferior frontal activation in dextrals, resulted in strong right hemispheric frontal activation. CONCLUSIONS: From our data there is clear evidence that different modalities, such as language perception and production, attention, and motor performance, are processed exclusively by 1 hemisphere when atypical cerebral dominance is present.- - - - - - - - - - ranking = 0.0060945547919367keywords = brain (Clic here for more details about this article) |
13/74. Late plasticity for language in a child's non-dominant hemisphere: a pre- and post-surgery fMRI study.The ability of the right hemisphere to sustain the acquisition or the recovery of language after extensive damage to the left hemisphere has been essentially related to the age at the time of injury. Better language abilities are acquired when the insult occurs in early childhood (perinatal insults) compared with later occurrence. However, while previous studies have described the neuropsychological pattern of language development in typical cases, the neural bases of such plasticity remain unexplored. Non-invasive functional MRI (fMRI) is a unique tool to assess the neural correlates of brain plasticity through repeated studies, but the technique has not been widely used in children because of methodological limitations. Plasticity of language was studied in a boy who developed intractable epilepsy related to Rasmussen's syndrome of the left hemisphere at age 5 years 6 months, after normal language acquisition. The first fMRI study at age 6 years 10 months showed left lateralization of language networks during a word fluency task. After left hemispherotomy at age 9 years, the child experienced profound aphasia and alexia, with rapid recovery of receptive language but slower and incomplete recovery of expressive language and reading. Postoperative fMRI at age 10 years 6 months showed a shift of language-related networks to the right during expressive and receptive tasks. Right activation was seen mainly in regions that could not be detected preoperatively, but mirrored those previously found in the left hemisphere (inferior frontal, temporal and parietal cortex), suggesting reorganization in a pre-existing bilateral network. In addition, neuropsychological data of this case support the hypothesis of innately more bilateral distribution of receptive than expressive language. This first serial fMRI study illustrates the great plasticity of the child's brain and the ability of the right hemisphere to take over some expressive language functions, even at a relatively late age. It also suggests a limit for removal of the dominant hemisphere beyond the age of 6 years, a classical limit for the critical period of language acquisition.- - - - - - - - - - ranking = 0.0027165083408374keywords = brain, injury (Clic here for more details about this article) |
14/74. Postlingual collapse of language and its recovery after cochlear implantation.A 6-year-old boy lost his normally-developed language ability within 2 months after bilateral sudden peripheral deafness. The boy became non-communicative with others, restless with frequent meaningless bursts of shouts (communication skills equivalent to 9-11 months of language development: a rapid breakdown of language). Since conservative methods were ineffective, cochlear implantation was performed. A surprising success was observed: he regained the language retracing the normal developmental stages and caught up with his contemporaries in 2 years. Behavioral improvement paralleled his language development. This case (1) provides insights into the brain function with respect to language acquisition, in relation to the plasticity during the 'critical period' of language learning, (2) reveals the close relationship between language development and behavior, and (3) suggests the predominance of auditory stimulation in learning language.- - - - - - - - - - ranking = 0.0012189109583873keywords = brain (Clic here for more details about this article) |
15/74. Language dysfunction in epileptic conditions.epilepsy may disrupt brain functions necessary for language development by its associated intellectual disabilities or directly as a consequence of the seizure disorder. Additionally, in recent years, there has been increasing recognition of the association of epileptiform electroencephalogram (EEG) abnormalities with language disorders and autism spectrum disorders. Any process that impairs language function has long-term consequences for academic, social, and occupational adjustments in children and adolescents with epilepsy. Furthermore, impairments in specific language abilities can impact memory and learning abilities. This article reviews interictal language function in children and adults with epilepsy; epilepsy surgery and language outcome; and language disorders associated with abnormal EEGs. The relationship between epilepsy and language function is complicated as the neuroanatomic circuits common to both overlap. We demonstrate how magnetoencephalography (MEG) offers the ability to analyze the relationship of language, EEG abnormalities, and epilepsy.- - - - - - - - - - ranking = 0.0012189109583873keywords = brain (Clic here for more details about this article) |
16/74. Neural regions essential for writing verbs.Functional imaging data collected during cognitive tasks show which brain regions are active during those tasks, but do not necessarily indicate which regions are essential for those tasks. Here, in a study of two cases of selectively impaired written naming of verbs after focal brain ischemia, we combined imaging and behavioral testing to unambiguously identify brain regions that are crucial for a specific cognitive process. We used magnetic resonance perfusion imaging to show that the selective impairment in each case was due to hypoperfusion (low blood flow) in left posterior inferior frontal gyrus (PIFG) and precentral gyrus (PrG); the impairment was immediately reversed when blood flow was restored to these regions, indicating that parts of the left frontal lobe are crucial for representing and processing verbs.- - - - - - - - - - ranking = 0.003656732875162keywords = brain (Clic here for more details about this article) |
17/74. Treatment of story grammar following traumatic brain injury: a pilot study.Recent investigations have documented a variety of discourse deficits following traumatic brain injuries (TBI). However, there is a paucity of information relating to the treatment of such deficits. The present study investigated the treatment of discourse production deficits, specifically story grammar ability, in an individual with TBI. Treatment emphasized meta-linguistic comprehension of story grammar structure and the identification and generation of episode components within stories. Over the course of treatment, a marked increase in the number of complete episodes generated by the individual with TBI was noted in story grammar probes. Follow-up probes at 1 and 3 months post-treatment, however, indicated limited carryover and poor generalization of the treatment effects. Findings are interpreted in terms of the individual's chronic cognitive deficits, disruptions in managerial knowledge, and the limitations of treating discourse acontextually.- - - - - - - - - - ranking = 0.92770310811586keywords = traumatic brain injury, brain injury, traumatic brain, brain, injury (Clic here for more details about this article) |
18/74. Molecular genetic delineation of a deletion of chromosome 13q12-->q13 in a patient with autism and auditory processing deficits.In a sporadic case of autism and language deficit due to auditory processing defects, molecular genetic studies revealed that a chromosomal deletion occurred in the 13q12-->q13 region. No chromosome abnormalities were detected in the parents. We determined that the deletion occurred on the paternally derived chromosome 13. There are two previous reports of chromosome 13 abnormalities in patients with autism. The deletion in the subject described in this paper maps between the two chromosome 13 linkage peaks described by Bradford et al. (2001) in studies of subjects with autism and language deficits. The 9-Mb region deleted in the patient described here contains at least four genes that are expressed in brain and that play a role in brain development. They are NBEA, MAB21L1, DCAMKL1 and MADH9. These genes therefore represent candidate genes for autism and specific language deficits.- - - - - - - - - - ranking = 0.0024378219167747keywords = brain (Clic here for more details about this article) |
19/74. Neuropsychological deficits in a child with a left penetrating brain injury.This case study reports neuropsychological and structural magnetic resonance (MRI) studies of a 10-year-old girl with a left hemisphere lesion, caused by an underwater fishing harpoon penetrating her head when she was 6 years old. The patient showed a marked deficit in the acquisition of reading, writing and arithmetic, as well as an attentional deficit. Magnetic resonance images revealed left cortical lesions in the orbital region and the gyrus angularis, as well as in the caudate and putamen nuclei and longitudinal inferior fascicle. Neuropsychological assessment showed frontal and parietal lobe dysfunctions consistent with the lesional data. The structural data explain the neuropsychological impairment and suggest that, although the left lesion was early and relatively small, plasticity was incomplete.- - - - - - - - - - ranking = 0.28472858475154keywords = brain injury, brain, injury (Clic here for more details about this article) |
20/74. Category-specific semantic deficits do not reflect the sensory/functional organization of the brain: a test of the "sensory quality" hypothesis.We report the performance of a herpes simplex encephalitis patient, EA, who shows a dissociation between poor performance for living things and spared performance for sensory quality categories, when appropriate measures are taken to control for baseline differences among categories in task difficulty and when we eliminate the contribution of visual processing deficits in the recognition of objects. This pattern of performance is problematic for theories of category-specific deficits that are based on the assumption that these deficits reflect selective damage to modality-specific semantic subsystems but is consistent with domain-specific accounts and theories based on the assumption that the structure of conceptual knowledge reflects the correlational structure among object properties.- - - - - - - - - - ranking = 0.0048756438335493keywords = brain (Clic here for more details about this article) |
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