The many faces of crossed aphasia in dextrals: report of nine cases and review of the literature.

A substantial body of the aphasia literature has been devoted to the topic of crossed aphasia in dextrals (CAD) over the past century but still no theory exists that explains the anomalous organization of neurocognitive functions in this population. However, if strict selection criteria are applied only some cases of vascular CAD are reported in which the correlation between neurocognitive disturbances and the locus of the brain lesion is studied. This study describes nine new cases of vascular CAD who underwent in-depth neurolinguistic and neuropsychological investigations. Our analysis shows the semiological variability of CAD phenomena and the many faces of the lesion-behaviour relationships of this exceptional neurobiological condition.