Non-nystagmus hyperkinetic eye movement disorders

While nystagmus is an involuntary ocular movement relatively frequent, well described, and easily recognized by most practitioners, non-nystagmus hyperkinetic eye movement disorders (NHEMD) are less obvious and can be overlooked. NHEMD may arise from intrinsic abnormalities in ocular muscles and oculomotor nerves, brain and brainstem lesions, systemic diseases, dysimmune disorders, drugs or can even be functional in nature. Given that some treatable disorders initially manifest with NHEMD, their knowledge becomes crucial.