title: Teaching video neuroimages: see-saw nystagmus.
abstract: A 43-year-old woman experienced a worsening of her usual headache. As a right hemifacial hypoesthesia had appeared, the patient underwent a brain MRI that revealed a giant cavernoma localized at the left meso-diencephalic region (figure, A and B). After the operation, an involuntary ocular oscillation known as see-saw nystagmus developed (video on the Neurology® Web site at www.neurology.org). See-saw nystagmus consists of alternating phases of intorsion of the elevating eye and extorsion of the descending eye.(1) The patient displayed a right head tilt with left hypertropia referred to as "ocular tilt reaction" (figure, C)-a phenomenon related to the imbalance in the graviceptive pathways between vestibular nuclei and the interstitial nucleus of Cajal (figure, D).(2.)
authors.affiliation: From the Department of Neurological Sciences (R.B.), Ospedale "G. Salvini," Garbagnate Milanese; the Oto-neurology Service (R.B.), Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan; and the Neuro-ophtalmology Service (S.B.M.), Fondazione IRCCS Istituto Auxologico Italiano, Milan, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Bassani
authors.forename: Stefania Bianchi
authors.initials: SB
authors.lastname: Marzoli
mesh_terms: D000328:Adult; D001921:Brain / Q000473:pathology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D059906:Neuroimaging / Q000379:methods; D009462:Neurology / Q000193:education; D009759:Nystagmus, Pathologic / Q000175:diagnosis* / Q000209:etiology