A common mechanism for the control of eye and head movements in humans

How the human brain controls the subtle coupling between eye and head movem ents is still debated. The brain could either coordinate two separate (eye and head) networks or use a single system involved in gaze (eye + head) con trol. In a recent report, a total transfer from eye to head movements was o bserved in a patient with congenital ophthalmoplegia. This led the authors to hypothesize that such transfer resulted from a long-term adaptation betw een oculomotor and head movement systems. We report on a patient in whom a similar transfer was observed but at the acute stage of an acquired ophthal moplegia. This case demonstrates that the transfer between head and eye mov ements does not necessarily require long-term adaptation and supports the h ypothesis of a common unique gaze motor command in which eye and head movem ents would be rapidly exchangeable.