PET evaluation of bilingual language compensation following early childhood brain damage.
We report a positron emission tomography (PET) study in a 37-year-old, right handed, bilingual (English and American Sign Language) male with left frontal lobe damage, without evidence of language or general intellectual dysfunction. A brain MRI scan demonstrated an atrophic lesion of the left dorsolateral prefrontal, orbital, and opercular cortices extending from the frontal pole to precentral gyrus and including parts of anterior cingulate cortex, due to an probable infantile encephalitis. H(2) (15)O PET scans found evidence of increased right hemisphere activity compared to normal controls during spontaneous generation of narrative in both English and ASL. Neuropsychological data were within normal limits with the exception of visuospatial function. The results suggest the possibility that plasticity, unmasking of neural pathways, and or other adaptations of language function in the right hemisphere may have occurred, and are discussed with regard to the crowding hypothesis.
Tierney
M C
MC
Cognitive Neuroscience Section, Medical Neurology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Building 10, Room 5C 205, Bethesda, MD 20892, USA.
Varga
M
M
Hosey
L
L
Grafman
J
J
Braun
A
A
D000328:Adult; D016022:Case-Control Studies; D004292:Dominance, Cerebral; D004660:Encephalitis / Q000150:complications; D005260:Female; D005625:Frontal Lobe / Q000000981:diagnostic imaging / Q000473:pathology* / Q000503:physiopathology; D006801:Humans; D007223:Infant; D007360:Intelligence; D007804:Language Development; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009473:Neuronal Plasticity; D009483:Neuropsychological Tests; D014055:Tomography, Emission-Computed