Triangle of Guillain-Mollaret

Update item information
Identifier OPT_figure_1_and_2
Title Triangle of Guillain-Mollaret
Subject Pendular Nystagmus; Oculopalatal Tremor
Creator Daniel R. Gold, DO, Departments of Neurology, Ophthalmology, Neurosurgery, Otolaryngology - Head & Neck Surgery, Emergency Medicine, and Medicine, The Johns Hopkins School of Medicine
Description Seen here is a schematic representation of the Gullain-Mollaret triangle (Figure 1), also referred to as the dentato-olivary pathway, reflecting the 3 points of this imaginary triangle - 1) dentate nucleus, 2) red nucleus, and 3) inferior olivary nucleus. The olive sends decussating climbing fibers through the contralateral inferior cerebellar peduncle that travel from the Purkinje cells of the cerebellar cortex to the dentate nucleus; the dentate sends decussating fibers (via the superior cerebellar peduncle) that wrap around the contralateral red nucleus; these fibers descend from red nucleus to the ipsilateral inferior olive via the central tegmental tract (CTT). Injury to any of these structures may result in oculopalatal tremor (OPT). Generally, OPT develops weeks to months following the inciting event (usually a brainstem hemorrhage), and vertical, vertical-torsional or torsional pendular nystagmus and palatal tremor can usually be appreciated on exam. Since the CTT normally inhibits the ipsilateral inferior olive, damage to the CTT results in decreased inhibition of the ipsilateral olive resulting from transsynaptic degeneration. Hypertrophic inferior olivary degeneration occurs as swollen and vacuolated neurons come into contact with each other, and corresponds to MRI T2/FLAIR hyperintensity (Figure 2). Cells of the inferior olive are electrically coupled by dendrodendritic gap junctions and are normally capable of generating spontaneous oscillations, but are inhibited by the CTT. When olivary denervation occurs, there is aberrant conduction between the soma of adjacent cells, causing synchronized oscillatory signals that are transmitted to the cerebellum where they are modulated and augmented. These rhythmic outputs generate nystagmus and palatal tremor. Nystagmus may be conjugate, dissociated or disjunctive. Nystagmus may be seen without palatal tremor, and palatal tremor may be seen without nystagmus (e.g., progressive ataxia and palatal tremor, PAPT), and synchronous contractions of other muscles from the branchial arches (larynx, pharynx, diaphragm, facial muscles) may also be appreciated. Shaikh AG, et al. Oculopalatal tremor explained by a model of inferior olivary hypertrophy and cerebellar plasticity. Brain. 2010 Mar;133(Pt 3):923-40. Tilikete C, Desestret V. Hypertrophic Olivary Degeneration and Palatal or Oculopalatal Tremor. Front Neurol. 2017; 8: 302.
Publisher Spencer S. Eccles Health Sciences Library, University of Utah
Date 2017
Type Image
Format image/jpeg
Relation is Part of NOVEL: Neuro-ophthalmology Virtual Education Library Examination Collection
Rights Management Copyright 2017. 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
Language eng
ARK ark:/87278/s62n8zjg
Setname ehsl_novel_gold
Date Created 2017-11-02
Date Modified 2021-05-06
ID 1278831
Reference URL https://collections.lib.utah.edu/ark:/87278/s62n8zjg
Back to Search Results