(DRG) Departments of Neurology, Ophthalmology, Neurosurgery, Otolaryngology - Head & Neck Surgery, Emergency Medicine, and Medicine, The Johns Hopkins School of Medicine, Baltimore, Maryland
Subject
Square wave jerks; Gaze evoked nystagmus
Description
When frequent square wave jerks (SWJ) are noted on examination (especially in a patient of advanced age), the examiner should look for signs of Parkinsonism as well as cerebellar ataxia. Patients who have SWJ with ocular motor signs such as gaze-evoked nystagmus (seen in this video), saccadic smooth pursuit, downbeat nystagmus, and/or saccadic dysmetria are likely to have a cerebellar localization.
