Lateral pontine stroke involving the superior vestibular nucleus causing spontaneous upbeat-torsional nystagmus

Update item information
Identifier Lateral_pontine_stroke_201909
Title Lateral pontine stroke involving the superior vestibular nucleus causing spontaneous upbeat-torsional nystagmus
Subject Jerk Nystagmus; Upbeat Nystagmus; Torsional Nystagmus; Pons; Acute Vestibular Syndrome
Creator Daniel R. Gold, DO, Departments of Neurology, Ophthalmology, Neurosurgery, Otolaryngology - Head & Neck Surgery, Emergency Medicine, and Medicine, The Johns Hopkins School of Medicine; Tzu-Pu Chang, MD, Department of Neurology/Neuro-Medical Scientific Center, Taichung Tzu Chi Hospital, Tzu Chi University', Buddhist Tzu Chi Medical Foundation, Taiwan
Description A 65-year-old man presented to the emergency department with spontaneous vertigo and unsteadiness, and had was noted to have spontaneous upbeat nystagmus (UBN), also with a torsional component (top poles beating toward the right ear) that was most noticeable in right and up gaze. General neurologic exam was non-focal although there was severe imbalance. Brain MRI demonstrated a small left dorsolateral pontine stroke (see end of video for diffusion-weighted imaging on the left and FLAIR on the right), that involved the left superior vestibular nucleus. While the posterior semicircular canal (SCC) afferents synapse in the vestibular nucleus and then ascend the medial longitudinal fasciculus (MLF) only, the anterior SCC afferents synapse in the vestibular nucleus and ascend via one of three pathways: 1) MLF, 2) ventral tegmental tract, and 3) brachium conjunctivum (BC, aka, superior cerebellar peduncle). Anterior SCC afferents synapse in the rostral SVN on their way to join the BC, and in this patient's case, it was thought that ischemia in this region was responsible for his UB-torsional nystagmus. Anterior SCC afferents destined for the BC would originate in the left labyrinth and synapse in the left SVN prior to their decussation. If left anterior SCC afferents were injured - normally responsible for torsional slow phase with top poles rotating toward the right ear and an upward slow phase (sometimes referred to as the "anti-gravity" pathway) - there would be a relative predominance of posterior SCC tone (causing downward slow phase) and right sided anterior and posterior SCC tone (causing torsional slow phase with top poles toward the left ear). These slow phases in turn generate fast phases upward (UBN) and torsional toward the right ear, which is what is seen in this patient. While UBN is typically thought to localize to the midline medulla or to paramedian pontomesencephalic regions (MLF, BC), this patient demonstrates that a lateral pontine insult can also cause this finding.
Publisher Spencer S. Eccles Health Sciences Library, University of Utah
Type Image/MovingImage
Format video/mp4
Rights Management Copyright 2019. For further information regarding the rights to this collection, please visit: https://NOVEL.utah.edu/about/copyright
Holding Institution Spencer S. Eccles Health Sciences Library, University of Utah, 10 N 1900 E, SLC, UT 84112-5890
Collection Neuro-ophthalmology Virtual Education Library: NOVEL http://NOVEL.utah.edu
File Name Lateral_pontine_stroke_201909.mp4
Language eng
ARK ark:/87278/s6kx02v4
Setname ehsl_novel_gold
Date Created 2019-09-10
Date Modified 2019-10-24
ID 1455032
Reference URL https://collections.lib.utah.edu/ark:/87278/s6kx02v4
Back to Search Results