1/27. Plasticity of language-related brain function during recovery from stroke.BACKGROUND AND PURPOSE: This study was undertaken to correlate functional recovery from aphasia after acute stroke with the temporal evolution of the anatomic, physiological, and functional changes as measured by MRI. methods: blood oxygenation level-dependent contrast and echo-planar MRI were used to map language comprehension in 6 normal adults and in 2 adult patients during recovery from acute stroke presenting with aphasia. perfusion, diffusion, sodium, and conventional anatomic MRI were used to follow physiological and structural changes. RESULTS: The normal activation pattern for language comprehension showed activation predominately in left-sided Wernicke's and Broca's areas, with laterality ratios of 0.8 and 0.3, respectively. Recovery of the patient confirmed as having a completed stroke affecting Broca's area occurred rapidly with a shift of activation to the homologous region in the right hemisphere within 3 days, with continued rightward lateralization over 6 months. In the second patient, in whom mapping was performed fortuitously before stroke, recovery of a Wernicke's aphasia showed a similar increasing rightward shift in activation recruitment over 9 months after the event. CONCLUSIONS: Recovery of aphasia in adults can occur rapidly and is concomitant with an activation pattern that changes from left to a homologous right hemispheric pattern. Such recovery occurs even when the stroke evolves to completion. Such plasticity must be considered when evaluating stroke interventions based on behavioral and neurological measurements.- - - - - - - - - - ranking = 1keywords = brain (Clic here for more details about this article) |
2/27. Dissociation of semantic and phonological errors in naming.We report the naming performance of a fluent aphasic, DP, who shows a striking dissociation between semantic and phonological (nonword) errors: he produced numerous semantic errors but virtually no phonological errors. DP's pattern of performance is the reverse of that reported for patient DM (Caramazza, Papagno, & Ruml, 2000), who only made phonological errors in a naming task. These patterns of performance are inconsistent with the proposal by Dell, Schwartz, Martin, Saffran, and Gagnon (1997) that the naming deficit in fluent aphasia is the result of global damage to all levels of the lexical access system and support instead the hypothesis that brain damage can selectively disrupt distinct subcomponents of the lexical processing system.- - - - - - - - - - ranking = 0.25keywords = brain (Clic here for more details about this article) |
3/27. Disorder in sequential speech perception: a case study on pure word deafness.We described disorders of a patient which were uniquely restricted to speech perception of syllable sequences after brain damage. The results of series of experiments using syllable sequences showed "negative recency effect," in which the subject's repetition performance at the latter syllable position was remarkably poor. Experimental analyses suggested that the "negative recency effect" could be due to dual factors: the lower rate of processing of speech sounds and the memory load of holding processes of preceding syllables imposed on the succeeding phonological processing. The results also suggested that the holding processes which imposed the memory load on the succeeding auditory phonological coding processing were modality nonspecific.- - - - - - - - - - ranking = 0.25keywords = brain (Clic here for more details about this article) |
4/27. Long-term treatment with idebenone and riboflavin in a patient with MELAS.We report a patient with MELAS treated for 24 months with idebenone and riboflavin, during which no stroke-like episodes occurred. Moreover neurological symptoms clearly improved, and a recovery of brain MRI and EEG abnormalities was observed. We conclude that the combined treatment with idebenone and riboflavin may restore the metabolic impairment in MELAS, possibly improving the long-term prognosis in these patients.- - - - - - - - - - ranking = 0.25keywords = brain (Clic here for more details about this article) |
5/27. Functional methods for evaluation the occurrence of delayed ischemic deficit in patients with subarachnoid hemorrhage.Detection of early circulatory and electrophysiologic changes due to vasospasm (VS) after subarachnoid hemorrhage (SAH) is a necessity for in-time and adequate therapeutic management. The aim of the present case report is to describe and demonstrate the results of transcranial Doppler (TCD) monitoring and brainstem auditory evoked potentials (BAEPs) examination, which indicate the development of combined circulatory insufficiency in two vascular systems. On the 14th day after SAH, TCD showed accelerated velocities in the territory of middle cerebral artery (MCA) and basilar artery (BA). BAEPs, after ipsilateral stimulation, performed on the same day verified changes of potentials on the left side with abnormal I/V amplitude ratio. These results were suggestive of brainstem dysfunction. The CT examination of the next day revealed infarction in the posterior parietal borderline zone of the left hemisphere. The patient had clinical signs of sensory aphasia, which resolved completely after one-week treatment with nimodipine.- - - - - - - - - - ranking = 0.5keywords = brain (Clic here for more details about this article) |
6/27. Fluent aphasia in children: definition and natural history.We compared the course of a preschool child we followed for 4 years with published reports of 24 children with fluent aphasia. Our patient spoke fluently within 3 weeks of the injury. She was severely anomic and made many semantic paraphasic errors. Unlike other children with fluent aphasia, her prosody of speech was impaired initially, and her spontaneous language was dominated by stock phrases. Residual deficits include chronic impairment of auditory comprehension, repetition, and word retrieval. She has more disfluencies in spontaneous speech 4 years after her head injury than acutely. School achievement in reading and mathematics remains below age level. attention to the timing of recovery of fluent speech and to the characteristics of receptive and expressive language over time will permit more accurate description of fluent aphasia in childhood.- - - - - - - - - - ranking = 0.004773311481902keywords = injury (Clic here for more details about this article) |
7/27. Morphologic agrammatism following a right hemisphere stroke in a dextral patient.There is evidence of two major components of grammatic function in the brain: (1) morphologic, probably based in the postcentral perisylvian cortex, encompassing the selection of individual words and inflectional endings according to the rules of grammar; and (2) syntactic, probably based in the frontal lobes, encompassing construction of the overall structure of a sentence (syntax) to match the concept being considered. We present a stroke patient with impaired morphology but, unlike Broca's aphasics, relative sparing of syntax. He omitted 43% of articles, 40% of complementizers, 20% of pronouns, 27% of semantically marked prepositions, 43% of purely grammatic prepositions, and 22% of auxiliary verbs, but his average sentence length was 9.8 words and 64% of his sentences contained embedded clauses. He frequently intermingled two sentences to convey a given concept, juxtaposing words in grammatically unacceptable ways. This intermingling may represent either a grammatic "conduite d'approche," or a failure of the filtering function of a defective morphologic processor. His great difficulty in completing syntactic frames suggests that a more general form of the processes underlying grammatic morphology may play an important role in phrase structure generation.- - - - - - - - - - ranking = 0.25keywords = brain (Clic here for more details about this article) |
8/27. A fluent language disorder following antepartum left-hemisphere brain injury.This article describes the development of language in a left-handed girl with a left middle cerebral artery infarction. Seven language samples of parent-child interaction, obtained when she was between 36 and 60 months of age, were transcribed and analyzed using the child language Data Exchange System. At 36 months of age, only 42 (20%) of the child's 214 utterances contained words; the other 80% were composed of jargon or interactional markers such as "uh-huh" and "uhn-uhn." Jargon incorporated familiar intonational contours and prosodic features to convey emotional states and communicative functions. Between 36 and 45 months of age, her jargon became differentiated into increasing approximations of English sentences. Simultaneously, her use of words and word combinations increased. By 54 months of age, no jargon was heard. The pattern of development observed in this child can be described as a transient jargon or fluent aphasia. It may have resulted from initial reliance on an uninjured right hemisphere. However, given the similarity between this pattern and the expressive or gestalt style of learning seen in some normal children, the pattern may also be related to other variables including characteristics of the parental input.- - - - - - - - - - ranking = 1.0095466229638keywords = brain, injury (Clic here for more details about this article) |
9/27. A case of cortical deafness and anarthria.Generally, cortical deafness is not complicated by anarthria and cortical anarthria does not affect auditory perception. We report a case of simultaneous progressive cortical deafness and anarthria. At the age of 70 years, the patient, a woman, noticed hearing problems when using the telephone, which worsened rapidly over the next 2 years. She was then referred to our hospital for further examinations of her hearing problems. Auditory tests revealed threshold elevation in the low and middle frequencies on pure-tone audiometry, a maximum speech discrimination of 25% and normal otoacoustic emissions and auditory brainstem, middle- and long-latency responses. An articulation test revealed abnormal pronunciation. Because of these problems only written and not verbal communication was possible; her ability to read and write was unimpaired. She showed no other neurological problems. brain MRI demonstrated atrophic changes of the auditory cortex and Wernicke's language center and PET suggested low uptake of (18F) 2-fluoro-2-deoxy-d-glucose around the Sylvian fissures in both hemispheres. Neurologically, the patient was suspected of having progressive aphasia or frontotemporal dementia. Her cortical deafness and anarthria are believed to be early signs of this entity.- - - - - - - - - - ranking = 0.25keywords = brain (Clic here for more details about this article) |
10/27. Functional MRI follow-up study of language processes in healthy subjects and during recovery in a case of aphasia.BACKGROUND AND PURPOSE: The goal of this study was to develop a functional MRI (fMRI) paradigm robust and reproducible enough in healthy subjects to be adapted for a follow-up study aiming at evaluating the anatomical substratum of recovery in poststroke aphasia. methods: Ten right-handed subjects were studied longitudinally using fMRI (7 of them being scanned twice) and compared with a patient with conduction aphasia during the first year of stroke recovery. RESULTS: Controls exhibited reproducible activation patterns between subjects and between sessions during language tasks. In contrast, the patient exhibited dynamic changes in brain activation pattern, particularly in the phonological task, during the 2 fMRI sessions. At 1 month after stroke, language homotopic right areas were recruited, whereas large perilesional left involvement occurred later (12 months). CONCLUSIONS: We first demonstrate intersubject robustness and intrasubject reproducibility of our paradigm in 10 healthy subjects and thus its validity in a patient follow-up study over a stroke recovery time course. Indeed, results suggest a spatiotemporal poststroke brain reorganization involving both hemispheres during the recovery course, with an early implication of a new contralateral functional neural network and a later implication of an ipsilateral one.- - - - - - - - - - ranking = 0.5keywords = brain (Clic here for more details about this article) |
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