Un caso di inversione delle competenze cognitive

It is universally accepted that the left hemisphere is dominant for language in a vast majority of subjects regardless of handedness (1,2), while the right hemisphere has specific competence for visuo-spatial skills (3). Partial exception to this cognitive rule can be found in cases with dominant right hemispheric language function. However, a complete reversal with left hemispheric dominance for visuo-spatial skills and right-sided dominance for language function, has never been explicitely demonstrated. We here describe the case of a woman with left temporal drug-resistant epilepsy candidate to surgery who did not show linguistic impairment during seizures. Using behavioural technicques (Wada Test, neuropsychological testing) and functional magnetic resonance (fMRI) measurements of brain activation we found clear-cut evidence of a reversed neurocognitive organization in this patient who underwent neurosurgery. Identification of similar cases with reversed hemispheric competences should help to discover a genetic basis for hemispheric specialization.