title: Epileptic nystagmus: A case report and systematic review.
abstract: OBJECTIVE
  We aimed to define the characteristics of epileptic nystagmus and correlate those with other clinical findings in a large number of patients.
  
  
  METHODS
  We report a patient with epileptic nystagmus and additionally reviewed the reported clinical features of 36 more patients through a systematic literature search. We analyzed the characteristics of epileptic nystagmus and attempted correlations of those with alertness of the patients and epileptic foci on EEG.
  
  
  RESULTS
  All 33 patients with unilateral horizontal nystagmus showed nystagmus beating away from the side of ictal discharges. Epileptic nystagmus was preceded by gaze deviation in 21 patients, with contraversive in 19 and ipsiversive in 2. Seizures associated with epileptic nystagmus were mostly focal (25/29, 86.2%) with or without loss of awareness. Ictal discharges originated from the occipital (n = 16), parietal (n = 9), temporo-occipital (n = 6), frontal (n = 4), and temporal (n = 3) areas, and two patients had multiple epileptic foci. Seizures were usually symptomatic (24/37, 64.9%). The presence of preceding gaze deviation and midline crossing of the nystagmus did not correlate with the ictal onset zone or alertness of the patients. Recording of epileptic nystagmus was available only in 6 patients, and the epileptic nystagmus could be localized to the saccadic areas in two and to the smooth pursuit areas in another two. Two patients showed the features of epileptic nystagmus from both areas.
  
  
  CONCLUSIONS
  Even though the localizing value of epileptic nystagmus seems limited in previous reports, the fast phase of epileptic nystagmus was almost always directed away from the epileptic focus that mostly arose from the posterior part of the cerebral hemisphere.
authors: Department of Neurology, Ajou University School of Medicine, Ajou University Hospital, Suwon, South Korea.
authors: Sun-Uk
authors: SU
authors: Lee
authors: Department of Neurology, Ajou University School of Medicine, Ajou University Hospital, Suwon, South Korea.
authors: Hong-Il
authors: HI
authors: Suh
authors: Department of Brain Sciences, Ajou University School of Medicine, Suwon, South Korea.
authors: Jun Young
authors: JY
authors: Choi
authors: Department of Neurology, Ajou University School of Medicine, Ajou University Hospital, Suwon, South Korea.
authors: Kyun
authors: K
authors: Huh
authors: Department of Biomedical Laboratory Science, Kyungdong University, Goseong, South Korea.
authors: Hyo-Jung
authors: HJ
authors: Kim
authors: Department of Neurology, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam, South Korea.
authors: Ji-Soo
authors: JS
authors: Kim
keywords: Epileptic nystagmus; Ictal nystagmus; Nystagmus; Seizure