Preserved Cognition After Right Hemispherectomy

Abstract

There is controversy regarding the unique contributions of the right and left hemispheres for human cognition. The right hemisphere is thought to play an important role in “nonverbal” cognitive abilities, such as visuospatial processing.¹ However, the necessity of the right hemisphere for other aspects of cognition has been challenged by the relative preservation of intellectual functioning following right hemispherectomy among children and, more rarely, adults with epilepsy due to congenital or early-onset right hemisphere pathology.^{2 3} The preservation of normal or near-normal cognition in these remarkable cases is often attributed to the capacity of the left hemisphere for early functional reorganization during development to compensate for cognitive functions that would have involved the right hemisphere in the absence of pathology. Cases of hemispherectomy in adults with normal development are exceptionally rare but could further inform our understanding of the necessity of the right hemisphere for various aspects of cognition.