The Experts below are selected from a list of 297 Experts worldwide ranked by ideXlab platform
Rai-chichan - One of the best experts on this subject based on the ideXlab platform.
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Efficacy of Synchronous Verbal Training During Repetitive Transcranial Magnetic Stimulation in Patients With Chronic Aphasia
Stroke, 2014Co-Authors: Chih-pinwang, Chin-yihsieh, Po-yitsai, Chia-towang, Fu-gonglin, Rai-chichanAbstract:Background and Purpose—Although multiple studies have suggested that repetitive transcranial magnetic stimulation (rTMS) may facilitate recovery after stroke, the efficacy of synchronous speech therapy integrated with an rTMS protocol has yet to be determined. We investigated language responses to this strategy and determined the longevity of the resulting therapeutic outcomes. Methods—Forty-five patients with stroke who presented with nonfluent Aphasia were randomly assigned to the TMSsyn group and underwent synchronous picture-naming training together with contralesional 1 Hz-rTMS for 10 daily sessions. The TMSsub group underwent subsequent picture-naming activity after the primed 1 Hz-rTMS, and the TMSsham group received concurrent naming task along with the sham 1 Hz-rTMS. The Concise Chinese Aphasia Test and the picture-naming Test were performed before, immediately, and after 3 months of the intervention. Results—TMSsyn showed significantly superior results in Concise Chinese Aphasia Test score (P
Diedrich Graf V. Keyserlingk - One of the best experts on this subject based on the ideXlab platform.
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diagnosis of Aphasia using neural and fuzzy techniques
Advances in Computational Intelligence and Learning: Methods and Applications, 2002Co-Authors: Jan Jantzen, Hubertus Axer, Diedrich Graf V. KeyserlingkAbstract:The language disability Aphasia has several sub-diagnoses such as Amnestic, Broca, Global, and Wernicke. Data concerning 265 patients is available in the form of Test scores and diagnoses, made by physicians according to the Aachen Aphasia Test. A neural network model has been built, which is available for consultation on the World Wide Web. The neural network model is in this paper compared with a fuzzy model. Rather than concluding which method provides the best approximation, the paper acts as an example solution useful for other benchmark studies.
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Advances in Computational Intelligence and Learning - Diagnosis of Aphasia Using Neural And Fuzzy Techniques
International Series in Intelligent Technologies, 2002Co-Authors: Jan Jantzen, Hubertus Axer, Diedrich Graf V. KeyserlingkAbstract:The language disability Aphasia has several sub-diagnoses such as Amnestic, Broca, Global, and Wernicke. Data concerning 265 patients is available in the form of Test scores and diagnoses, made by physicians according to the Aachen Aphasia Test. A neural network model has been built, which is available for consultation on the World Wide Web. The neural network model is in this paper compared with a fuzzy model. Rather than concluding which method provides the best approximation, the paper acts as an example solution useful for other benchmark studies.
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supra and infrasylvian conduction Aphasia
Brain and Language, 2001Co-Authors: Hubertus Axer, Georg Berks, Armgard Grafin V Keyserlingk, Diedrich Graf V. KeyserlingkAbstract:Fifteen cases of conduction Aphasia which were Tested with the Aachen Aphasia Test (AAT), are presented. The CT lesion data were transformed to a standard 3D-reference brain referring to the ACPC line. According to the lesion profiles a group of 6 patients had pure suprasylvian lesions, a group of 4 patients had pure infrasylvian lesions, and a group of 5 patients had lesions in both supra- and infrasylvian regions. Suprasylvian conduction aphasics are superior to infrasylvian conduction aphasics in the token Test and in repetition tasks. Infrasylvian conduction aphasics use more stereotypes in spontaneous speech than suprasylvian conduction aphasics. Conduction aphasics with both lesion sites perform less well in Tests of naming, writing, and comprehension than the pure types. Thus conduction Aphasia is a heterogeneous syndrome anatomically and linguistically.
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an Aphasia database on the internet a model for computer assisted analysis in aphasiology
Brain and Language, 2000Co-Authors: Hubertus Axer, Jan Jantzen, Diedrich Graf V. KeyserlingkAbstract:A web-based software model was developed as an example for data mining in aphasiology. It is used for educating medical and engineering students. It is based upon a database of 254 aphasic patients which contains the diagnosis of the Aphasia type, profiles of an Aphasia Test battery (Aachen Aphasia Test), and some further clinical information. In addition, the cerebral lesion profiles of 147 of these cases were standardized by transferring the coordinates of the lesions to a 3D reference brain based upon the ACPC coordinate system. Two artificial neural networks were used to perform a classfication of the Aphasia type. First, a coarse classification was achieved by using an assessment of spontaneous speech of the patient which produced correct results in 87% of the Test cases. Data analysis tools were used to select four features of the 30 available Test features to yield a more accurate diagnosis. This classifier produced correct results in 92% of the Test cases. The neural network approach is similar to grouping performed in group studies, while the nearest-neighbor method shows a design more similar to case studies. It finds the neurolinguistic and the lesion data of patients whose AAT profiles are most similar to the user's input. This way lesion profiles can be compared to each other interindividually. The Aphasia Diagnoser is available on the Web address http://fuzzy.iau.dtu.dk/Aphasia.nsf and thus should facilitate a discussion about the reliability and possibilities of data-mining techniques in aphasiology.
Hubertus Axer - One of the best experts on this subject based on the ideXlab platform.
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diagnosis of Aphasia using neural and fuzzy techniques
Advances in Computational Intelligence and Learning: Methods and Applications, 2002Co-Authors: Jan Jantzen, Hubertus Axer, Diedrich Graf V. KeyserlingkAbstract:The language disability Aphasia has several sub-diagnoses such as Amnestic, Broca, Global, and Wernicke. Data concerning 265 patients is available in the form of Test scores and diagnoses, made by physicians according to the Aachen Aphasia Test. A neural network model has been built, which is available for consultation on the World Wide Web. The neural network model is in this paper compared with a fuzzy model. Rather than concluding which method provides the best approximation, the paper acts as an example solution useful for other benchmark studies.
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Advances in Computational Intelligence and Learning - Diagnosis of Aphasia Using Neural And Fuzzy Techniques
International Series in Intelligent Technologies, 2002Co-Authors: Jan Jantzen, Hubertus Axer, Diedrich Graf V. KeyserlingkAbstract:The language disability Aphasia has several sub-diagnoses such as Amnestic, Broca, Global, and Wernicke. Data concerning 265 patients is available in the form of Test scores and diagnoses, made by physicians according to the Aachen Aphasia Test. A neural network model has been built, which is available for consultation on the World Wide Web. The neural network model is in this paper compared with a fuzzy model. Rather than concluding which method provides the best approximation, the paper acts as an example solution useful for other benchmark studies.
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supra and infrasylvian conduction Aphasia
Brain and Language, 2001Co-Authors: Hubertus Axer, Georg Berks, Armgard Grafin V Keyserlingk, Diedrich Graf V. KeyserlingkAbstract:Fifteen cases of conduction Aphasia which were Tested with the Aachen Aphasia Test (AAT), are presented. The CT lesion data were transformed to a standard 3D-reference brain referring to the ACPC line. According to the lesion profiles a group of 6 patients had pure suprasylvian lesions, a group of 4 patients had pure infrasylvian lesions, and a group of 5 patients had lesions in both supra- and infrasylvian regions. Suprasylvian conduction aphasics are superior to infrasylvian conduction aphasics in the token Test and in repetition tasks. Infrasylvian conduction aphasics use more stereotypes in spontaneous speech than suprasylvian conduction aphasics. Conduction aphasics with both lesion sites perform less well in Tests of naming, writing, and comprehension than the pure types. Thus conduction Aphasia is a heterogeneous syndrome anatomically and linguistically.
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an Aphasia database on the internet a model for computer assisted analysis in aphasiology
Brain and Language, 2000Co-Authors: Hubertus Axer, Jan Jantzen, Diedrich Graf V. KeyserlingkAbstract:A web-based software model was developed as an example for data mining in aphasiology. It is used for educating medical and engineering students. It is based upon a database of 254 aphasic patients which contains the diagnosis of the Aphasia type, profiles of an Aphasia Test battery (Aachen Aphasia Test), and some further clinical information. In addition, the cerebral lesion profiles of 147 of these cases were standardized by transferring the coordinates of the lesions to a 3D reference brain based upon the ACPC coordinate system. Two artificial neural networks were used to perform a classfication of the Aphasia type. First, a coarse classification was achieved by using an assessment of spontaneous speech of the patient which produced correct results in 87% of the Test cases. Data analysis tools were used to select four features of the 30 available Test features to yield a more accurate diagnosis. This classifier produced correct results in 92% of the Test cases. The neural network approach is similar to grouping performed in group studies, while the nearest-neighbor method shows a design more similar to case studies. It finds the neurolinguistic and the lesion data of patients whose AAT profiles are most similar to the user's input. This way lesion profiles can be compared to each other interindividually. The Aphasia Diagnoser is available on the Web address http://fuzzy.iau.dtu.dk/Aphasia.nsf and thus should facilitate a discussion about the reliability and possibilities of data-mining techniques in aphasiology.
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fuzzy clustering a versatile mean to explore medical databases
2000Co-Authors: Georg Berks, Jan Jantzen, Mariagrazia Dotoli, Hubertus AxerAbstract:A clinical syndrome is a set or a cluster of concurrent symptoms which indicate together the presence and the nature of a disease. Looking for concurrent symptoms is therefore one of the main tasks in medical diagnosis. In medicine imprecise conditions are the rule and therefore fuzzy methods are more suitable than crisp ones. We used fuzzy c-means clustering to assign symptoms to the different types of Aphasia categories. The results were compared with the results in some subTests of the Aachen Aphasia Test (AAT). The polarization of the five main factors leads to at least 10 different categories. The description of language failures by c-mean classification of the analyzed factors corresponds in many but not in all cases to the traditional diagnostic scheme.
Klaus Willmes - One of the best experts on this subject based on the ideXlab platform.
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Cross linguistic Aphasia Testing: the Portuguese version of the Aachen Aphasia Test (AAT).
Journal of the International Neuropsychological Society : JINS, 2008Co-Authors: Martin Lauterbach, Isabel Pavão Martins, Paula Garcia, Joana Cabeça, Ana Cristina Ferreira, Klaus WillmesAbstract:We report the adaptation of the Aachen Aphasia Test (AAT) to the Portuguese language (PAAT) and the results of its standardization in 125 persons with Aphasia and 153 healthy controls. Patients with Aphasia had a previous syndromic diagnosis, obtained through a Portuguese Aphasia battery, which served as a reference. The control group was stratified by age and educational level. Hierarchical cluster analyses showed good construct validity. The increasing degree of difficulty and complexity throughout the item sets comprising subTests was confirmed. The discriminatory power of the PAAT for the selection of aphasic from non-aphasic persons proved to be as high as for the AAT versions in other languages. Classification of standard aphasic syndromes by means of discriminant analyses was good. Internal consistency, measured by means of Cronbach's alpha coefficient, was high to very high for the different PAAT subTests. Performance differences caused by age or educational level among the healthy control persons emphasized the need for correction factors. In conclusion, the PAAT showed robust psychometrical properties, comparable to the original German and to adaptations to other languages. It constitutes a useful tool for cross-linguistic and multicenter studies. ( JINS , 2008, 14 , 1046–1056.)
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The psychometric properties of the English language version of the Aachen Aphasia Test (EAAT)
Aphasiology, 2000Co-Authors: Nick Miller, Klaus Willmes, R. De BleserAbstract:This article reports results of a standardization study of the English language version of the Aachen Aphasia Test (EAAT). The EAAT was administered to 135 speakers with and 93 without Aphasia. Aphasic speakers were divided into four groups (n =30) representing EAAT standard syndrome groups (global, amnestic, Broca's and Wernicke's Aphasia), and 15 speakers who could not be classified into the standard groups. Without Aphasia were 24 nonhospitalized and 41 hospitalized speakers with no history of neurological illness or speech-language disorder and 28 speakers with a history of neurological illness, but no Aphasia. Hierarchical cluster analysis (complete linkage) demonstrated the validity of the linguistically motivated construction of the EAAT. This was further confirmed for the main subTests through nonmetric multidimensional scaling (smallest space analysis). The property of increasing complexity across subparts of subTests was also confirmed. Nonparametric discriminant analyses showed the high differe...
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the aachen Aphasia bedside Test criteria for validity of psychologic Tests
Nervenarzt, 1992Co-Authors: R Biniek, Klaus Willmes, Walter Huber, R Glindemann, H KlummAbstract:The Aachen Aphasia Bedside Test (AABT) has been developed in order to examine aphasic patients within the first 4 to 6 weeks after onset of illness. The psychometric properties of the AABT were established by repeated examination of 82 acute stroke patients, ratings by 20 raters on the basis of 10 videotapes, repeated examination of 28 chronic aphasics three times with an interval of 2 days, and parallel examination of 47 chronic aphasic patients with the AABT and the Aachen Aphasia Test (AAT), administered on the same day. Objectivity, reliability and validity of the AABT were highly rated, indicating its usefulness in acute stroke cases. Data on the 82 acute stroke patients showed that an initial prognosis can be made as early as the fourth day after the stroke.
Manuela Sailer - One of the best experts on this subject based on the ideXlab platform.
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constraint induced Aphasia therapy following sub acute stroke a single blind randomised clinical trial of a modified therapy schedule
Journal of Neurology Neurosurgery and Psychiatry, 2014Co-Authors: Almut Sickert, Lutz Christian Anders, Thomas F Munte, Manuela SailerAbstract:Background and purpose The trend towards a shorter stay in rehabilitation clinic has implications for future language therapy. Constraint-induced Aphasia therapy (CIAT) is administered 3 h per day for a total of 30 h of treatment. It was evaluated for patients with chronic Aphasia. In the present study we investigated the efficacy of a modified CIAT schedule and included patients with sub-acute stroke. We conducted a randomised, single-blind, parallel-group study. The results were compared to those of patients who received identically intensive treatment focusing on conventional Aphasia therapy. Methods Fifty patients were treated with our modified version of CIAT and 50 received a standard Aphasia therapy at the same intensity and duration. Inclusion criteria were clinical diagnosis of first-ever stroke, Aphasia in the sub-acute stage and German speakers. Language function was evaluated using the Aachen Aphasia Test and the Communicative Activity Log directly before therapy onset, after the training period and at 8-week and 1-year follow-ups. Results Patients of both groups improved significantly in all sub-Tests of the Aachen Aphasia Test Battery. The improvements remained stable over a 1-year follow-up period. Patients and relatives of both groups rated daily communication as significantly improved after therapy. Conclusions Both CIAT and conventional therapy performed with equal intensity are efficacious methods for patients with sub-acute Aphasia. The modified CIAT schedule is practical in an everyday therapeutic setting. Our results indicate that a short-term intensive therapy schedule in the early Aphasia stage leads to substantial improvements in language functions. Clinical Trial Registration Information Clinical Trial Registration-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01625676