Byron Bernal

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In aphasia literature, it has been considered that a speech repetition defect represents the main constituent of conduction aphasia. Conduction aphasia has frequently been interpreted as a language impairment due to lesions of the arcuate fasciculus (AF) that disconnect receptive language areas from expressive ones. Modern neuroradiological studies suggest(More)
BACKGROUND AND PURPOSE Proton MR spectroscopy ((1)H-MR spectroscopy) is a potentially useful adjunct to anatomic MR imaging in the characterization of brain tumors. We performed an updated systematic review of the evidence. METHODS We employed a standardized search strategy to find studies published during 2002-2004. We reviewed studies measuring(More)
PURPOSE The left superior longitudinal fasciculus (SLF) has been felt to link receptive with expressive language areas. The latter is located in the pars opercularis (Broca's area) of the left inferior frontal gyrus. We report the findings with tractography of the SLF in a group of normal volunteers. METHODS AND MATERIALS The data and subsidiary results(More)
PURPOSE To map developing areas of activation with functional magnetic resonance (MR) imaging in sedated children by using passive auditory and visual tasks. MATERIALS AND METHODS Forty children between 2 months and 9 years old were examined and grouped according to age. Children were selected from patients referred to undergo brain MR imaging. Patients(More)
The field of the neurobiology of language is experiencing a paradigm shift in which the predominant Broca-Wernicke-Geschwind language model is being revised in favor of models that acknowledge that language is processed within a distributed cortical and subcortical system. While it is important to identify the brain regions that are part of this system, it(More)
Long association cortical fiber pathways support developing networks for speech and language, but we do not have a clear understanding of how they develop in early childhood. Using diffusion-weighted imaging (DWI) we tracked the frontal aslant tract (FAT), arcuate fasciculus (AF), and AF segments (anterior, long, posterior) in 19 typical 5-8-year-olds, an(More)
fMRI can define language cortex but its limitations are not yet fully understood. This article describes a child in whom fMRI falsely lateralized language cortex when performed after a cluster of left temporal lobe seizures. Multiple language tasks revealed no activation over the left temporal lobe despite a normal neurologic exam at the time of the study.(More)
PURPOSE To compare the total direct costs (fixed and variable costs) of functional magnetic resonance (MR) imaging and of the Wada test for evaluation of language lateralization. MATERIALS AND METHODS The direct fixed and variable costs of functional MR imaging (performed in 21 patients with mean age +/- SD of 15.5 years +/- 8.9) and of the Wada test(More)
PURPOSE To determine the role of functional magnetic resonance (MR) imaging in assessing hemispheric language dominance in epilepsy and nonepilepsy populations. MATERIALS AND METHODS A Bayesian analysis study was performed. The study was based on data from the published literature; thus, institutional review board approval was not required. The literature(More)
Paradigms exploring cognitive inhibition involve motor responses, which may confound the results. We compare cognitive inhibition activation obtained without motor involvement, to motor inhibition alone, in a group of young right-handed volunteers, utilizing a classical color Stroop task (CST), and a Stop Task. Comparison of fMRI activation was performed(More)