Brain regions essential for improved lexical access in an aged aphasic patient: a case report

BACKGROUND: The relationship between functional recovery after brain injury and concomitant neuroplastic changes is emphasized in recent research. In the present study we aimed to delineate brain regions essential for language performance in aphasia using functional magnetic resonance imaging and acquisition in a temporal sparse sampling procedure, which allows monitoring of overt verbal responses during scanning. CASE PRESENTATION: An 80-year old patient with chronic aphasia (2 years post-onset) was investigated before and after intensive language training using an overt picture naming task. Differential brain activation in the right inferior frontal gyrus for correct word retrieval and errors was found. Improved language performance following therapy was mirrored by increased fronto-thalamic activation while stability in more general measures of attention/concentration and working memory was assured. Three healthy age-matched control subjects did not show behavioral changes or increased activation when tested repeatedly within the same 2-week time interval. CONCLUSION: The results bear significance in that the changes in brain activation reported can unequivocally be attributed to the short-term training program and a language domain-specific plasticity process. Moreover, it further challenges the claim of a limited recovery potential in chronic aphasia, even at very old age. Delineation of brain regions essential for performance on a single case basis might have major implications for treatment using transcranial magnetic stimulation

Early electroencephalography in acute ischemic stroke: Prediction of a malignant course?

(c) 2006 Elsevier B.V. All rights reserved

Early electroencephalography in acute ischemic stroke: Prediction of a malignant course?

(c) 2006 Elsevier B.V. All rights reserved

Functional imaging in the assessment of capability for recovery after stroke

Copyright 2003 TAYLOR & FRANCIS A

Essential language function of the right hemisphere in brain tumor patients

© 2005 The American Neurological Associatio

Role of the contralateral inferior frontal gyrus in recovery of language function in poststroke aphasia - A combined repetitive transcranial magnetic stimulation and positron emission tomography study

© 2005 The American Heart Association, Inc

From the left to the right: How the brain compensates progressive loss of language function

(c) 2006 Elsevier Inc. All rights reserved

Neuroimaging-guided rTMS of the left inferior frontal gyrus interferes with repetition priming

Thiel A, Haupt WF, Habedank B, et al. Neuroimaging-guided rTMS of the left inferior frontal gyrus interferes with repetition priming. NEUROIMAGE. 2005;25(3):815-823.Neuroimaging studies of right-handed normal volunteers under semantic word generation tasks have consistently reported left lateralized activation of the anterior inferior frontal gyros (ifg) which decreased during task repetition. This repetition-related activation decrease has been interpreted as the neurophysiological correlate of repetition priming, a mechanism of implicit memory for initial semantic processing. We interfered with left lateralized ifg activation, as identified by 0-15-water PET activation, using repetitive transcranial magnetic stimulation (rTMS) in five right-handed male normal subjects, once using new (unprimed) nouns and once using known (primed) nouns for the procedure. All five subjects exhibited clear left lateralized activations of the triangular part of the left ifg in the PET studies. In all subjects, reaction time latencies were significantly longer during rTMS over the activation sites in the left ifg as compared to latencies off stimulation. Latencies were not affected during stimulation of the right ifg or over the vertex. These effects were observed within the group and in each individual, only if lists of primed nouns were used in the verb-generation task. In conclusion, these results demonstrate that the anterior part of the left ifg is not only involved in semantic processing, but is also essential for repetition priming on semantic tasks since successful interference with rTMS was only observed if lists of primed words were used for the generation task. (c) 2004 Elsevier Inc. All rights reserved