1/38. Representation of linguistic rules in the brain: evidence from training an aphasic patient to produce past tense verb morphology.We trained a patient with expressive aphasia and a deficit in phoneme-to-grapheme conversion to produce spoken English verbs with correct tense morphology. After training, he showed evidence of generalization to production of written regular, but not irregular, verbs in a sentence completion task. These data support dual-route, rule-based models within the brain for morphosyntactic operations.- - - - - - - - - - ranking = 1keywords = brain (Clic here for more details about this article) |
2/38. Frontal-opercular aphasia.The standard nomenclature divides nonfluent aphasic syndromes with relatively spared comprehension into Broca's aphasia and transcortical motor aphasia. We report on a patient with a persistent nonfluent aphasia from a discrete, primarily cortical, frontal-opercular lesion who had impaired syntax but intact repetition and, therefore, did not conform to the traditional classification. Based on this patient's behavior and a review of other cases, we have divided the nonfluent aphasias with intact comprehension into five disorders. (1) Verbal akinesia-exhibiting diminished intention or drive to speak and associated with medial frontal lesions (supplementary motor area and cingulate gyrus) or with lesions damaging the efferent projections from these areas. (2) Disorders of syntax-telegraphic and agrammatic utterances that may be associated with dominant pars opercularis lesions. (3) Phonemic disintegration-a failure to correctly produce phonemes, which may be associated with injury to the opercular primary motor cortex or efferent projections from this area. (4) Defects of lexical access-patients who struggle to find words and are impaired at timed word-generation tasks. Defects of lexical access may be associated with lesions of the pars triangularis and adjacent prefrontal cortex. (5) Mixed defects. According to this model, the traditional patient with Broca's aphasia would exhibit disorders of syntax, phonemic disintegration, and defects of lexical access, whereas the traditional patient with transcortical motor aphasia would have verbal akinesia or defects of lexical access or both. Our patient had defects of lexical access and syntax, but only mild symptoms of phonemic disintegration, suggesting that his opercular primary motor cortex was relatively intact. Our patient's ability to repeat normally while his propositional speech remained telegraphic suggests that different neural mechanisms subserve these functions.- - - - - - - - - - ranking = 0.0057238072886818keywords = injury (Clic here for more details about this article) |
3/38. Using fMRI to study recovery from acquired dysphasia.We have used functional magnetic resonance imaging (fMRI) to characterize brain activations associated with two distinct language tasks performed by a 28-year-old woman after partial recovery from dysphasia due to a left frontal hemispheric ischemic stroke. MRI showed that her ischemic lesion extended posteriorly from the left inferior frontal to the perisylvian cortex. fMRI scans of both language tasks revealed substantial differences in activation pattern relative to controls. The nature of this difference was task-specific. During performance of a verbal semantic decision task, the patient, in contrast to controls, activated a network of brain areas that excluded the inferior frontal gyrus (in either hemisphere). A second task involving rhyme judgment was designed to place a heavier cognitive load on language production processes and activated the left inferior frontal gyrus (Broca's area) strongly in normal controls. During this task, the most prominent frontal activation in the patient occurred in the right homologue of Broca's area. Subsequent analysis of this data by methods able to deal with responses of changing amplitude revealed additional, less sustained recruitment by the patient of cortex adjacent to the infarct in the region inferior to Broca's area during rhyming. These results suggest that in addition to changes in cognitive strategy, recovery from dysphasia could be mediated by both the preservation of neuronal networks in and around the infarct and the use of homologous regions in the contralateral hemisphere.- - - - - - - - - - ranking = 0.4keywords = brain (Clic here for more details about this article) |
4/38. Acute aphasia in multiple sclerosis.Acute aphasia is rare in multiple sclerosis. We describe 3 patients with multiple sclerosis who had acute exacerbations presenting as aphasias. One patient had a mixed transcortical aphasia, 1 had a transcortical motor aphasia, and 1 had a Broca aphasia. magnetic resonance imaging scans of the brain with contrast enhancement revealed new white matter lesions in the left hemisphere in all 3 patients. Two of the 3 patients had a good response to treatment with methylprednisolone sodium succinate. Arch Neurol. 2000;57:1207-1209- - - - - - - - - - ranking = 0.2keywords = brain (Clic here for more details about this article) |
5/38. Intensive training of phonological skills in progressive aphasia: a model of brain plasticity in neurodegenerative disease.Three patients with a typical syndrome of nonfluent primary progressive aphasia (Mesulam's syndrome) were trained daily with a remediation protocol including auditory exercises specifically designed to involve several aspects of phonological processing, a domain known to be specifically affected in the condition. The speech content of the exercises was based on the temporal theory of phonological processes according to which increasing the duration of formant transition should facilitate phoneme discrimination and phoneomic awareness. Significantly improved performance on the trained tasks was demonstrated in the three patients. Improvement further generalized to other tasks such as nonword repetition and reading. We conclude that such results (1) argue for using intensive focused therapy of language impairment in neurodegenerative disorders, (2) may constitute a good model of brain plasticity in neurodegenerative disorders in general, and (3) support theories of phonological processing emphasizing temporal features of the auditory signal.- - - - - - - - - - ranking = 1keywords = brain (Clic here for more details about this article) |
6/38. Symptomatic epilepsy with facial myoclonus triggered by language.We report on a patient with a left frontal lesion who, many years after an injury, developed non-fluent aphasia and facial myoclonic jerks triggered by speaking and listening to spoken language. At age 57, the patient first noted that he would begin to stutter when delivering lectures at conferences. The stuttering would worsen if he continued talking. The video-polygraphic EEG recording shows brief paroxysms of spikes and polyspikes, followed by a slow wave, more evident in the left fronto-temporal region. The myoclonic jerks originating from the submental area correlate with EEG abnormalities. Clinically, these jerks determined a form of stuttering. The triggering factors were reading, speaking and listening to spoken language. This case had several characteristic features: facial myoclonus was the only seizure type experienced by the patient; the seizures and language impairment had a very late onset--about 50 years after the traumatic event that produced a dramatic lesion in the left fronto-polar region. (Published with videosequences.)- - - - - - - - - - ranking = 0.0057238072886818keywords = injury (Clic here for more details about this article) |
7/38. Grammatical processing of nouns and verbs in left frontal cortex?We report the case of a brain-damaged subject R.C. who is more impaired at producing grammatical forms of words and pseudo-words used as verbs (he judges, he wugs) than of the same words used as nouns (the judges, the wugs). This pattern of performance constitutes the first clear demonstration that grammatical knowledge about verbs can be selectively impaired following brain damage. A comparison of R.C.'s behavioral and neurological profile with that of a patient who shows similar difficulties with nouns suggests that nouns and verbs are processed by separate neural systems with components in the left frontal lobe.- - - - - - - - - - ranking = 0.4keywords = brain (Clic here for more details about this article) |
8/38. Right hemispheric dysfunction in a case of pure progressive aphemia: fusion of multimodal neuroimaging.This article describes the unusual case of a 60-year-old woman suffering from pure progressive aphemia. The fusion of multimodal neuroimaging (MRI, perfusion SPECT) implicated the right frontal lobe, especially the inferior frontal gyrus. This area also showed the greatest functional MRI activation during the performance of a covert phonemic fluency task. Results are discussed in terms of bihemispheric language representation. The fusion of three sets of neuroimages has aided in the interpretation of the patient's cognitive brain dysfunction.- - - - - - - - - - ranking = 0.2keywords = brain (Clic here for more details about this article) |
9/38. The effects of motor neurone disease on language: further evidence.It might sound surprising that Motor Neurone disease (MND), regarded still by many as the very example of a neurodegenerative disease affecting selectively the motor system and sparing the sensory functions as well as cognition, can have a significant influence on language. In this article we hope to demonstrate that language dysfunction is not only a pronounced and well documented symptom in some MND patients but also that the study of language in MND can address interesting theoretical questions about the representation of language and conceptual knowledge in the brain. After a brief introduction delineating clinical and pathological features of the disease we discuss the evidence available in the literature for language dysfunction in MND. We then present linguistic data from our own study of seven patients with MND/dementia/aphasia syndrome focusing on the dissociation between noun and verb processing. To illustrate the clinical, neuropsychological and linguistic aspects of MND we describe in more detail the patient E.N., a pathologically confirmed case of MND/dementia. Finally, we attempt to characterise the nature of the linguistic impairment in MND in the light of current debates about the mechanisms underlying noun/verb dissociation.- - - - - - - - - - ranking = 0.2keywords = brain (Clic here for more details about this article) |
10/38. Foreign accent syndrome: anatomic, pathophysiologic and psychosocial considerations.The appearance of new onset accented speech after brain insult has been rarely reported. stroke is often responsible for the development of what has been termed foreign accent syndrome (FAS). Foreign Accent syndrome was initially described by Pick in 1919, and further elaborated on by Monrad-Krohn in 1947. Manifestations include disruption in segmental and prosodic elements of speech, which results in a listener's perception of the speech as foreign. In the majority of these rare cases, the patients present without having been exposed to the accent in the past. However, reports of a spoken accent in which the patient had significant previous exposure to in the past have been described. We report a case in which a woman developed a Germanic accent coinciding with the return of speech several days following an embolic left-hemispheric cortical infarction. The underlying neuroanatomical and pathophysiological explanations are reviewed. Additionally, the psychosocial consequences of this rare phenomenon are discussed.- - - - - - - - - - ranking = 0.2keywords = brain (Clic here for more details about this article) |
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