Aberrant regeneration involving the oculomotor and abducens nerves.

An unusual case of severe head trauma is reported with postoperative 'total' ophthalmoplegia of the right eye. Subsequent recovery led to an apparent transposition of right medial and right lateral rectus function. Optokinetic stimulation induced convergence nystagmus when the target was moved to the patient's left, and a divergence nystagmus when the target was moved to the patient's right. In addition, attempted lateral gaze induced ipsilateral pupillary constriction. Aberrant regeneration involving the right abducens and right oculomotor nerves is proposed as the underlying mechanism.