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Distributed anatomy of transcortical sensory aphasia   总被引:7,自引:0,他引:7  
We examined four patients with transcortical sensory aphasia and eight with milder language disturbances but with similar thalamic and/or temporo-occipital lesions. Specific attention was paid to differentiation of the computed tomographic lesion site of the milder cases from the transcortical sensory aphasia cases. The critical lesion for transcortical sensory aphasia in these patients involved pathways in the posterior periventricular white matter adjacent to the posterior temporal isthmus, pathways that are probably converging on the inferolateral temporo-occipital cortex. Analysis of the language function of these patients, of the influence of sensory modalities on language function, and of the interaction between semantic memory and semantic lexical functions suggests the existence of a specific brain system for semantic functions. This semantic system has a particular distributed anatomy. We propose that damage to this system may have a variety of clinical manifestations in language and in memory, depending on the exact lesion configuration.  相似文献   

3.
目的分析汉语失读特点并探讨其机制。方法对6例经皮质感觉性失语并深部失读患者做补充阅读检查——92个词先朗读,后配画或解释。结果6例有85个错读词。48个词义错读词中大多可正确配画或解释;19个近形错读词和11个近音错读词中大多不能正确配画或解释。7个部分词朗读中3个可正确配画。结论字的视觉传入可激活词义系统,但由于字位-音位转换有缺陷致不能正确选择而出现词义错读。错读的语音可激活语音系统,但从同音异义字中选择有缺陷。未证明汉字朗读有语音途径。  相似文献   

4.
A typical case of transcortical sensory aphasia (TSA) is presented, in which the Wada test suggests that it is the right hemisphere which enables the patient to repeat orally. It is supposed that one of the mechanisms of preserved repetition in TSA is linked to an exceptional ability for repetition of the right hemisphere, which may help to explain why cases of TSA are so rare.  相似文献   

5.
Altholgh Lichtheim recognized that Wernicke's 'reflex arch' (primary auditory area, to Wernicke's area, to Broca's area, to primary motor area) was important for repetition, he recognized that other areas of the brain (for example, area of concepts or semantic area) must be important in comprehension and voluntary speech. He suggested that Wernicke's area (phonemic area) not only projected to Broca's area (as Wernicke suggested) but that it also projected to the area of concepts. A lesion of this latter pathway or in the area of concepts would produce a syndrome where repetition was intact but comprehension was impaired (e.g. transcortical sensory aphasia). Lichtheim also thought that the area of concepts projected directly to Broca's area and that voluntary speech was mediated by this pathway. Although Lichtheim's model could explain the mechanism underlying transcortical aphasia, his schema could not explain anomic aphasia. Unlike Lichtheim's schema, Kussmaul's schema suggested that the area of concepts projects back to Wernicke's area before projecting to Broca's area. With this schema, a patient with a hypothetical lesion which interrupted the pathway from the area of concepts to Wernicke's area (but did not interrupt the pathway from Wernicke's area to the area of concepts) should be anomic, with normal comprehension and repetition. In order for this latter schema to be plausible there should also be a lesion which interrupts the pathway from Wernicke's area to the area of concepts but does not interrupt the pathway which goes from the area of concepts to Wernicke's area. A patient with this hypothetical lesion should comprehend poorly; however, in spite of poor comprehension, naming and repetition should be intact. We report a patient who demonstrates poor comprehension with intact naming and repetition. This patient could also read aloud but could not comprehend written language. Not only could this patient name objects but he could demonstrate their use. These observations suggest that comprehension of written language is mediated by a different pathway than the recognition of visually presented objects.  相似文献   

6.
An autopsy case of transcortical motor aphasia is presented with a pathology located anterior and superior to the pars opercularis of the left inferior frontal gyrus. Case H. Y. A 60-year-old right-handed man. On Nov. 14, 1978, the patient had surgery to remove cerebral hematoma in the left frontal lobe. In the neuropsychological examination before the operation, he had shown the clinical features of transcortical motor aphasia characterized by good comprehension of language, preserved repetition, and spontaneous speech disorder. In this stage, it was supposed that the underlying disturbance of spontaneous speech was due to the disabilities of contextual constructions of sentences rather than the lack of speech initiation. Following the operation, however, spontaneous speech disappeared completely for several days. At the same time, the patient showed problems in comprehension, reading, writing and confrontation naming as well as symptoms of disorientation, pathological inertia and 'loss of initiation' in the psychomotor domain. During the following three months, however, the patient did show slight improvement, except for contextual sentence constructions and pathological inertia when taking the complex animal drawing test. In his terminal stages, the clinical symptoms could be summarized as transcortical motor aphasia and mild frontal lobe syndrome. On March 1, 1979, the patient died of Hamman-Rich syndrome. Postmortem examination: The brain weighed 1294 gm. The external observation of the brain disclosed the linear tissue defect, about 15 mm in length and 10 mm in width, along the radial sulcus of the pars triangularis of the left inferior frontal gyrus.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

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Aim  We report the case of a 6-year-old female who suffered a left hemisphere stroke attributed to a genetically determined prothrombotic state. She presented a fluent speech pattern with selective difficulty in retrieving names but not verbs. An evaluation was designed to clarify whether her symptoms represented a specific impairment of name retrieval.
Method  The child undertook an experimental battery of visual naming tasks requiring the production of 52 nouns (belonging to nine different semantic categories) and 44 verbs. Her performance was compared with that of 12 healthy children, matched for age and IQ, attending a local kindergarten.
Results  The child retrieved significantly more verbs than nouns ( χ 2=16.27, p <0.01) and had a significantly lower score in noun ( t =−7.2, p <0.005), but not in verb retrieval than the comparison group. This pattern persisted when verbs and nouns were matched for oral word frequency, showing that the results could not be explained by stimuli difficulty.
Interpretation  To our knowledge, this is the first report of a grammatical dissociation in a child. It suggests that nouns and verbs are subject to different processing early in development, at least before the formal acquisition of grammar. It contradicts theories that postulate a common processing of different grammatical categories early in life.  相似文献   

9.
Two patients, ages 51 and 76 years, suddenly developed transcortical motor aphasia combined with pyramidal signs and ataxia of the right extremities that affected the leg more severely than the arm. Computed tomography revealed nonenhancing lucencies in the distribution territory of the left anterior cerebral artery involving the genu of the corpus callosum, white matter ventral to the left frontal horn, medial primary motor area, supplementary motor area, and superior part of the premotor area. It is postulated that aphasia, ataxia, and weakness resulted from involvement of the supplementary motor area and deep white matter, premotor, and primary motor areas, respectively. Anterior cerebral artery infarctions of the dominant hemisphere may result in transcortical motor aphasia associated with contralateral ataxic hemiparesis.  相似文献   

10.
An 81-year-old woman with left medial frontal lobe hematoma, which involved the supplementary motor area, is reported. She was right-handed and was initially mute for several hours after the onset. On admission, she exhibited mild paresis of the right lower extremity. Her spontaneous speech was sparse and not fluent, but her articulation and auditory comprehension were normal and repetition was good. She exhibited excellent performance in the confrontation naming task, but showed difficulty in recalling words from a given category during the word fluency task. On the basis of these clinical features, she was diagnosed as having transcortical motor aphasia. Our case may corroborate previous findings that the left medial frontal lobe is important in word fluency but not in confrontation naming.  相似文献   

11.
Abstract

Patients with transcortical motor aphasia frequently demonstrate an ‘akinesia of speech’ resulting in decreased word fluency, reduced syntactic complexity, and diminished speech initiative. A treatment protocol targeting verbal generativity in terms of communicative expansion was instituted in this case study to address the patient's deficit area—deficient linguistic planning and goal setting. The patient demonstrated adequate lexical and syntactic skills and improved sentence generation performance as a result of treatment. However, treatment effects were short-lived as the patient returned to pre-treatment levels on the generalization measures three months post-discharge.  相似文献   

12.
A case of acquired conduction aphasia in a child   总被引:2,自引:0,他引:2  
A 10-year-old right-handed boy showed conduction aphasia with left-ear verbal extinction (paradoxical ipsilateral ear extinction) after removal of a arteriovenous malformation in the left parietal lobe. Buccofacial and ideomotor apraxia were not observed. Recovery from aphasia was dramatic. Postoperative computed tomography (CT) and magnetic resonance imaging scans demonstrated damage confined to the left supramarginal gyrus invading the arcuate fasciculus. Together with recently reported cases of acquired fluent aphasia in children with CT-verified left posterior lesions, this case seems to support the current view that both fluent and nonfluent aphasia that share many similarities with the symptoms and lesion localization associated with adult cases may exist in children.  相似文献   

13.
Anatomic basis of transcortical motor aphasia   总被引:3,自引:0,他引:3  
Analysis of language profiles and CT anatomy in transcortical motor aphasia (TCMA) suggests that the essential lesion is disruption of connections at sites between the supplementary motor area and the frontal perisylvian speech zone. If the lesion is extended, there may also be poor articulation (lesion deep to motor strip for face), impaired auditory comprehension (lesion in anterior head of caudate, anterior limb internal capsule, anterior putamen, and anterior portion of external capsule, claustrum, extreme capsule, and insula), or stuttering (lesion in pars opercularis and lower third of premotor region). This concept unifies disparate anatomic and psychophysiologic observations about three syndromes: classical TCMA, aphasia after left medial frontal infarction, and TCMA during recovery from Broca's aphasia.  相似文献   

14.
Background: Previous studies have demonstrated that stimulus factors, including item frequency, presentation rate, stimulus repetition, and semantic relatedness, can influence the rate of recurrent verbal perseverations. These manipulations alter the balance of activation between current targets and past responses, suggesting that perseverations arise when the activation of a previously presented item overrides the weak processing of a new stimulus. By this view, cues and sentence contexts that bias inter‐item competition towards the target and away from earlier responses should dramatically reduce the frequency of perseverative errors. However, the influence of these factors on perseverations has not been previously investigated.

Aims: To examine the effect on perseverative rate of altering the activational balance between past and present responses using both intrinsic and extrinsic stimulus manipulations.

Methods & Procedures: This study examined repetition, reading, and picture naming in a highly perseverative patient with transcortical sensory aphasia.

Outcomes & Results: The patient's strong perseverative tendencies were impervious to the stimulus factors listed above but he was able to overcome these errors to produce more correct responses when he was provided with phonemic, word, and sentence cues. These environmental constraints had a similar effect on perseverations in reading aloud and picture naming, although active repetition was necessary for a cue to benefit reading, whereas passively hearing the cue was sufficient to improve picture naming.

Conclusions: This task difference is likely to reflect the greater reliance of picture naming on semantic processing, which will benefit from cues regardless of whether they are repeated. We propose that poor internal control of language production allowed perseverations to dominate our patient's output. External constraints in the form of cues/sentence contexts overcame this deficit, dramatically reducing the rate of perseverations.  相似文献   

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Background: Recent studies imply that executive functions (EF) are closely related to our ability to comprehend and produce language. A number of findings suggest that functional communication and language recovery in aphasia depend not only on intact language abilities but on EF as well. Some patients with transcortical motor aphasia (TMA) show language deficits only in tasks in which conflicting representations must be resolved by executive processes. In line with these results, others have proposed that TMA should be referred to as “dysexecutive aphasia”. EF in aphasia have mostly been studied using neuropsychological tests, therefore there is a need for systematic experimental investigations of these skills.

Aims: 1. To investigate EF in TMA, and to test whether executive dysfunctions are specific to TMA. 2. To experimentally measure different components of EF: updating working memory representations and inhibition of prepotent responses.

Methods & Procedures: Five individuals with TMA, five patients with conduction aphasia and ten healthy controls participated. We designed four nonverbal tasks: to measure updating of working memory representations, we used a visual and an auditory n-back task. To assess inhibition of prepotent responses, we designed a Stop-signal and a nonverbal Stroop task. All tasks involved within-subject baseline conditions.

Outcomes & Results: We found certain EF deficits in both groups of individuals with aphasia as compared to healthy controls. Individuals with TMA showed impaired inhibition as indexed by the Stop-signal and the nonverbal Stroop tasks, as well as a deficit of updating of working memory representations as indexed by the auditory n-back task. Participants with conduction aphasia had difficulties in only one of the tasks measuring inhibition, but no clear evidence for impairment of updating of working memory representations was found.

Conclusions: Although the results show different patterns of EF deficits in the groups with aphasia, the findings clearly demonstrate that EF deficits are not specific to participants with TMA. Based on these results, and on earlier data highlighting the role of executive processes in functional communication and language recovery, we suggest that tests of EF should be an inherent part of clinical aphasia assessment.  相似文献   

17.
Background: Nonfluent verbal production in individuals with transcortical motor aphasia (TMA) relates primarily to impaired initiation of verbalisation. Luria (1973) proposed the notion of gestural reorganisation, limb movements used to provoke verbalisations, as a means to improve verbal initiation in aphasia. In particular, movements performed with the left hand in left space may engage right frontal mechanisms to enhance verbal initiation (Crosson, Singletary, Richards, Koehler, & Rothi, 2000). However, little evidence is available as to the effects of this type of treatment for nonfluent verbal production in TMA. Aims: We administered a treatment in which we incorporated nonsymbolic limb movements during production of sentences and evaluated the effects on verbal fluency in our participant, MP, who had TMA. Methods & Procedures: We used a single-participant experimental treatment design across behaviours. During training, MP tapped with his left hand in left space as he practised production of sentences for polysemous words (e.g., bank: money, river). In daily probes, we measured percent correct sentences generated and time to produce correct sentences for trained and untrained polysemous words, as well as number of words generated per minute in a control letter category fluency task. Outcomes & Results: Sentence-generation accuracy improved in two trained sets and one untrained set when movement was included during treatment. Little change was evident in the control letter category fluency task. Following training, MP produced increased numbers of words and well-formed utterances in connected speech samples as well. Conclusions: These findings suggest that movement training had some benefit for MP's sentence generation, perhaps due to recruitment of alternative frontal regions to enhance verbal initiation and fluency. Replication is needed with similar subjects who undergo treatment in conjunction with functional neuroimaging to evaluate this possibility.  相似文献   

18.
In a previous functional magnetic resonance imaging (fMRI) study with normal subjects, we demonstrated regions related to conceptual-semantic word processing around the first frontal sulcus (BA 9) and the posterior parietal lobe (BA 7/40) in agreement with several previous reports. We had the possibility, using the same fMRI paradigm, to study two consecutive cases with left middle cerebral artery (MCA) infarction (RC and HP) and lesions affecting either solely the pre-frontal (HP) or both the pre-frontal and posterior parietal part of the network activated in normal subjects (RC). Both patients showed transcortical sensory aphasia (TSA) on acute assessment. This contradicts classical disconnection accounts of the syndrome stating intact conceptual representations in TSA. Their recovery of language comprehension was associated with activation of a left hemispheric network. Mainly activations of left perilesional pre-frontal regions (RC), left Wernicke's area (RC and HP) or the left posterior middle and inferior temporal cortex (HP) were demonstrated in the TSA patients. The latter findings suggest that in our cases of TSA functional take-over has occurred in regions with related functions ('redundancy recovery') rather than in previously unrelated areas ('vicarious functioning'). Our data support distributed models of conceptual-semantic word processing and multiple left hemispheric representations of closely related functions.  相似文献   

19.
Repetition of affective prosody in mixed transcortical aphasia   总被引:3,自引:0,他引:3  
Two patients with mixed transcortical aphasia could repeat propositional speech but not affective prosody. These findings suggest that the intact perisylvian region responsible for propositional speech does not mediate effective prosody. We propose that affective prosody is incorporated into propositional speech by means of an interhemispheric mechanism and that the failure of these patients to repeat affective prosody was caused by a disconnection of the left perisylvian structures from the right hemisphere structures thought to mediate affective prosody.  相似文献   

20.
A 4-year-old child was referred to us from neurology with a possible diagnosis of autism. This form of acquired aphasia is unusual in that our patient did not ever present any clinical seizure in spite of bilateral temporal injury. One of the etiological possibilities that has been retained in those cases has to do with the aphasia being related to the convulsive disorder. Our case suggests that, at least for some of those children suffering from this unusual form of acquired aphasia, one has to look for some other etiological possibilities. This last point will be discussed as well as the value of sleep EEG as a diagnostic procedure.  相似文献   

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