Diagnostic value of vertical nystagmus recorded from ENG

A patient with a cerebellar hemorrhage was evaluated using electronystagmography (ENG). Data obtained on the horizontal channel were only mildly abnormal. However, vertical nystagmus was clearly evident when the patient was tested in a darkened room with eyes open. This additional procedure may have saved the patient severe complications. With eyes open in darkness vertical nystagmus is more easily differentiated from eye blinks and clinicians are encouraged to look for this valuable central vestibular system sign.