ABSTRACT
Objective@#To investigate the correlation between damage to the dominant arcuate fasciculus (AF) and the occurrence of auditory comprehension dysfunction in post-stroke aphasia.@*Methods@#Eighteen stroke survivors with non-fluent aphasia were recruited into the observation group, and nine healthy counterparts were chosen for the control group. All received diffusion tensor imaging (DTI) scans and fractional anisotropy (FA) values were measured. A Chinese aphasia battery was used to evaluate the aphasics′ language functioning, with the listening true or false, listening recognition and oral instruction auditory comprehension sub-scales used as the observation indices.@*Results@#There were significant differences between the two groups in the FA value of the dominant AF. Spearman correlation showed that the FA value of the dominant AF was positively related to the listening recognition results.@*Conclusions@#Damage to the dominant AF may be one of the reasons for auditory comprehension dysfunction in post-stroke aphasia. It is significantly related to listening recognition.
ABSTRACT
Objective To investigate the correlation between damage to the dominant arcuate fasciculus ( AF) and the occurrence of auditory comprehension dysfunction in post-stroke aphasia. Methods Eighteen stroke survivors with non-fluent aphasia were recruited into the observation group, and nine healthy counterparts were chosen for the control group. All received diffusion tensor imaging ( DTI) scans and fractional anisotropy ( FA) values were measured. A Chinese aphasia battery was used to evaluate the aphasics' language functioning, with the listening true or false, listening recognition and oral instruction auditory comprehension sub-scales used as the observation indices. Results There were significant differences between the two groups in the FA value of the dominant AF. Spearman correlation showed that the FA value of the dominant AF was positively related to the listening recognition results. Conclusions Damage to the dominant AF may be one of the reasons for auditory comprehension dysfunction in post-stroke aphasia. It is significantly related to listening recognition.
ABSTRACT
Using diffusion tensor tractography (DTT), we demonstrated injury of the arcuate fasciculus (AF) in the nondominant hemisphere in two patients who showed subfalcine herniation after intracerebral hemorrhage (ICH) in the dominant hemisphere. Two patients (patient 1 and patient 2) with ICH and six age-matched control patients who have ICH on the left corona radiata and basal ganglia without subfalcine herniation were recruited for this study. DTT was performed at one month after onset in patient 1 and patient 2. AFs of both hemispheres in both patients were disrupted between Wernicke's and Broca's areas. The fractional anisotropy value and tract numbers of the right AFs in both patients were found to be more than two standard deviations lower than those of control patients. In contrast, the apparent diffusion coefficient value was more than two standard deviations higher than those of control patients. Using the configuration and parameters of DTT, we confirmed injury of the AF in the nondominant hemisphere in two patients with subfalcine herniation following ICH in the dominant hemisphere. Therefore, DTT would be a useful tool for detection of underlying injury of the AF in the nondominant hemisphere in patients with subfalcine herniation.
Subject(s)
Humans , Anisotropy , Basal Ganglia , Cerebral Hemorrhage , DiffusionABSTRACT
Diffusion tensor imaging is a non-invasive MRI technique which can identify changes of cerebral microstructure that CT and MRI is difficult to find, especially in the change of nerve fibers direction, which can be used for the researches of evaluation, recovery mech-anism and prognosis of neurology. It has been applied in rehabilitation of motor, language and recognition of post-stroke patients.
ABSTRACT
@# Diffusion tensor imaging is a non-invasive MRI technique which can identify changes of cerebral microstructure that CT and MRI is difficult to find, especially in the change of nerve fibers direction, which can be used for the researches of evaluation, recovery mechanism and prognosis of neurology. It has been applied in rehabilitation of motor, language and recognition of post-stroke patients.
ABSTRACT
There are individuals who have a progressive language deficit without presenting cognitive deficits in other areas. One of the diseases related to this presentation is primary progressive aphasia (PPA). OBJECTIVE: Identify by means of diffusion tensor imaging (DTI) and measurements of cortical volume, brain areas that lead to dysphasia when presenting signs of impaired connectivity or reduced volume. METHOD: Four patients with PPA were evaluated using DTI, and measurements of cortical volumes in temporal areas. These patients were compared with two normal volunteers. RESULTS: There is a trend to a difference in the number and volume of related fibers between control group and patients with PPA. Comparing cortical volumes in temporal areas between groups yielded a trend to a smaller volume in PPA patients. CONCLUSION: Patients with PPA have a trend to impairment in cortical and subcortical levels regarding relevant areas.
Existem indivíduos que apresentam deterioração progressiva da linguagem sem apresentar déficits em outros domínios cognitivos; estes pacientes em geral apresentam afasia primária progressiva (APP). OBJETIVO: Identificar, pela imagenologia, áreas cerebrais que quando sofrem atrofia, ou quando seu sistema de conexões apresenta alterações, levam a disfasia. MÉTODO: Foram avaliados quatro pacientes com APP, utilizando-se ressonância magnética com as técnicas de imagem por tensores da difusão (DTI) e medida do volume cortical em áreas de interesse previamente definidas. Estes pacientes foram comparados com um grupo controle constituído por dois voluntários. RESULTADOS: Redução da média dos volumes dos giros temporais esquerdos no grupo de pacientes, em relação ao grupo controle, e alterações quanto ao volume e número de fibras nos tratos correspondentes. CONCLUSÃO: Pacientes com APP têm tendência a apresentar danos tanto ao nível cortical quanto subcortical.
Subject(s)
Aged , Aged, 80 and over , Humans , Middle Aged , Aphasia, Primary Progressive/pathology , Brain/pathology , Case-Control Studies , Diffusion Tensor ImagingABSTRACT
La afasia de conducción es un trastorno caracterizado por un lenguaje espontáneo relativamente fluido, buena comprensión, pero dificultades en la repetición asociadas con parafasias fonológicas. Se ha atribuido a lesiones del fascículo arqueado por desconexión entre el lóbulo temporal posterior y el frontal, sin embargo se ha debatido esta postura, planteando que la integridad y funcionamiento del fascículo arqueado no es indispensable en la repetición verbal. Se presenta un caso de un sujeto varón de 23 años que, como consecuencia de un astrocitoma anaplásico recidivante que abarca áreas parietales y temporo-occipitales, presenta una afasia de conducción. Se plantea una reconceptualización de esta afasia, analizándola en términos clínicos, neuropsicológicos y en las redes neuronales existentes entre áreas cerebrales posteriores ipsilaterales y contralaterales.
Conduction aphasia is a language disorder characterized by an impaired ability to repeat verbal material associated with phonological paraphasias but a relatively fluent spontaneous speech and preserved comprehension. It has been attributed to lesions of the arcuate fasciculus by disconnection between posterior temporal lobe and frontal lobe, however, this idea has been debated, because the integrity and function of the arcuate fasciculus does not seem to be essential in verbal repetition. We report a case of a 23 year old male, with conduction aphasia as a result of a recurrent anaplastic astrocytoma in parietal and temporo-occipital areas. We propose a reconceptualization of the aphasia, analyzing it in terms of clinical neuropsychological and neural networks between ipsilateral and contralateral posterior brain areas.
Subject(s)
Aphasia , Aphasia/physiopathology , Brain Diseases/physiopathology , Cognition DisordersABSTRACT
OBJECTIVE: To investigate the neuroanatomical correlation of conduction aphasia by analyzing neuroimage data of patients who were diagnosed as conduction aphasia after stroke. METHOD: Nine patients with conduction aphasia after stroke were retrospectively reviewed with their medical records. Language functions of patients were assessed by Korean-version Western Aphasia Battery (K-WAB). Stroke lesions were assessed by brain computed tomography or magnetic resonance images taken within 1 month after onset of stroke. RESULTS: The stroke subtypes were cerebral infarction in 5 patients and intracranial hemorrhage in 4 patients. The lesions were located in left hemisphere in 8 subjects and right hemisphere in 1 subject. The left hemispheric lesion were located in the insula and superior temporal lobe in 3, the inferior parietal lobe in 2, the corona radiate in 1, the basal ganglia in 1 patient and both corona radiata and basal ganglia in 1. The right hemispheric lesion was located in the inferior parietal and superior temporal lobe. CONCLUSION: 6 of 9 patients with conduction aphasia had brain lesions in the path of arcuate fasciculus in the left hemisphere, however, 3 of 9 patients showed other brain lesions. These findings suggested that conduction aphasia could be caused by heterogeneous brain lesions. The characteristic features of conduction aphasia according to diverse brain lesions may need further investigation.