Upbeat Nystagmus: Clinicoanatomical Correlations in 15 Patients.
- Author:
Ji Soo KIM
1
;
Bora YOON
;
Kwang Dong CHOI
;
Sun Young OH
;
Seong Ho PARK
;
Byung Kun KIM
Author Information
- Publication Type:Original Article
- Keywords: Upbeat nystagmus; Vestibulo-ocular reflex; Neural integrator
- MeSH: Brain; Brain Stem; Cerebral Hemorrhage; Cerebral Infarction; Eye Protective Devices; Head; Humans; Hydrocephalus; Infarction; Magnetic Resonance Imaging; Mesencephalon; Multiple Sclerosis; Negotiating; Ocular Motility Disorders; Pons; Reflex, Vestibulo-Ocular; Supine Position; Thalamus; Wernicke Encephalopathy
- From:Journal of Clinical Neurology 2006;2(1):58-65
- CountryRepublic of Korea
- Language:English
- Abstract: BACKGROUND AND PURPOSE: The mechanism of upbeat nystagmus is unknown and clinicoanatomical correlative studies in series of patients with upbeat nystagmus are limited. METHODS: Fifteen patients with upbeat nystagmus received full neuro-ophthalmological evaluation by the senior author. Nystagmus was observed using video Frenzel goggles and recorded with video-oculography. Brain lesions were documented with MRI. RESULTS: Lesions responsible for nystagmus were found throughout the brainstem, mainly in the paramedian area: in the medulla (n=8), pons (n=3), pons and midbrain with or without cerebellar lesions (n=3), and midbrain and thalamus (n=1). Underlying diseases comprised cerebral infarction (n=10), multiple sclerosis (n=2), cerebral hemorrhage (n=1), Wernicke encephalopathy (n=1), and hydrocephalus (n=1). Upbeat nystagmus was mostly transient and showed occasional evolution during the acute phase. In one patient with a bilateral medial medullary infarction, the upbeat nystagmus changed into a hemiseesaw pattern with near complete resolution of the unilateral lesion. Gaze and positional changes usually affected both the intensity and direction of the nystagmus. A patient with a cervicomedullary lesion showed a reversal of upbeat into downbeat nystagmus by straight-head hanging and leftward head turning while in the supine position. Gaze-evoked nystagmus (n=7), ocular tilt reaction (n=7), and internuclear ophthalmoplegia (n=4) were also commonly associated with upbeat nystagmus. CONCLUSIONS: In view of the responsible lesions and associated neuro-ophthalmological findings, upbeat nystagmus may be ascribed to damage to the pathways mediating the upward vestibulo-ocular reflex or the neural integrators involved in vertical gaze holding.
