Format

Send to

Choose Destination
J Clin Neurol. 2006 Mar;2(1):58-65. doi: 10.3988/jcn.2006.2.1.58. Epub 2006 Mar 20.

Upbeat nystagmus: clinicoanatomical correlations in 15 patients.

Author information

1
Department of Neurology, College of Medicine, Seoul National University, Seongnam, Korea.

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.

KEYWORDS:

Neural integrator; Upbeat nystagmus; Vestibulo-ocular reflex

Supplemental Content

Full text links

Icon for Korean Neurological Association Icon for PubMed Central
Loading ...
Support Center