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Plasticity of language networks in patients with brain tumors: A positron emission tomography activation study
Author(s) -
Thiel Alexander,
Herholz Karl,
Koyuncu Adem,
Ghaemi Mehran,
Kracht Lutz W.,
Habedank Birgit,
Heiss WolfDieter
Publication year - 2001
Publication title -
annals of neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.764
H-Index - 296
eISSN - 1531-8249
pISSN - 0364-5134
DOI - 10.1002/ana.1253
Subject(s) - laterality , neuroscience , positron emission tomography , psychology , lateralization of brain function , temporal lobe , neuroplasticity , temporal cortex , cerebellum , frontal lobe , superior temporal gyrus , brain mapping , epilepsy , functional magnetic resonance imaging
Abstract We investigated plasticity of language networks exposed to slowly evolving brain damage. Single subject O‐15‐water language activation positron emission tomography studies were analyzed in 61 right‐handed patients with brain tumors of the left hemisphere, and 12 normal controls. In controls, activations were found in left Brodmann's Area (BA)44 and BA45, superior posterior temporal gyrus bilaterally, and right cerebellum. Patients additionally activated left BA46, BA47, anterior insula, and left cerebellum. Superior temporal activation was less frequent, and activations in areas other than posterior temporal gyrus were found bilaterally. Frontolateral activations within the nondominant hemisphere were only seen in patients (63%) with frontal or posterior temporal lesions. Laterality indices of frontolateral cortex showed reversed language dominance in 18% of patients. Laterality indices of the cerebellum were negatively correlated with language performance. Two compensatory mechanisms in patients with slowly evolving brain lesions are described: An intrahemispheric mechanism with recruitment of left frontolateral regions other than classic language areas; and an interhemispheric compensatory mechanism with frontolateral activation in the nondominant hemisphere. The latter one was only found in patients with frontal or posterior temporal lesions, thus supporting the hypothesis that right frontolateral activations are a disinhibition phenomenon.