Crossed Aphasia in a Dextral With Right Hemispheric Lesion: A Functional Transcranial Doppler Study

To the Editor:I read with interest the article by Hund-Georgiadis et al1 on crossed nonaphasia in a dextral with left hemispheric lesions published in the November 2001 issue of Stroke . They concluded from their data that different modalities such as language perception and production, attention, and motor performance are processed exclusively by one hemisphere when atypical cerebral dominance is present. They also suggested that the underlying functional organization of language remains rare and unclear in these cases. Our studies in normal subjects using functional transcranial Doppler (fTCD) suggest that this may not be rare after all. Left hemispheric lateralization for language was found in 61.5% of neurologically intact dextrals.2 Human pathology data obtained by Geschwind and Levitsky3 found that the planum temporale of the temporoparietal junction is larger in the left hemisphere in ≈60% of the population.3 Furthermore, there was a high incidence of right-hemisphere lateralization for language in as much as 38.5% of neurologically intact dextrals.2 Dyslexics had a pattern that was opposite the normal pattern.2 Recently, the use of functional MRI and fTCD offers new approaches with more precise determinations of cerebral lateralization for language. To support the …