| Identifier |
003-2 |
| Title |
Palatal Tremor |
| Creator |
Shirley H. Wray, MD, PhD, FRCP |
| Contributors |
Steve Smith, Videographer |
| Affiliation |
(SHW) Professor of Neurology, Harvard Medical School; Director, Unit for Neurovisual Disorders, Massachusetts General Hospital, Boston, Massachusetts |
| Subject |
Palatal Tremor (Myoclonus); Pendular Vertical Oscillations; Unilateral Horizontal Gaze Palsy; Facial Palsy; Pontine Infarct; Degenerative Hypertrophy of the Inferior Olivary Nucleus; Lesion in the Guillain-Mollaret Triangle; Oculopalatal Myoclonus; Oculopalatal Tremor |
| History |
This patient presented with an acute brainstem stroke with: 1. A unilateral lower motor neuron (LMN) facial palsy on the right 2. A horizontal gaze palsy to the right 3. Mild unsteadiness walking The infarct localized clinically to the right side of the pons involving the abducens nucleus and the genu of the facial nerve. Approximately two to three months following the stroke, the patient developed constant oscillations of her eyes. A diagnosis was made of: 1. Pendular vertical oscillations 2. Horizontal right gaze palsy 3. Right LMN facial palsy 4. Palatal tremor Comment: Lesions of the inferior olivary nucleus or its connections may produce this syndrome of oculopalatal tremor (myoclonus). This condition, which usually develops weeks to months after infarction or hemorrhage affecting the brainstem, cerebellum, or superior cerebellar peduncle, is relatively rare. Oculopalatal tremor may also occur with degenerative conditions. The main pathologic finding with palatal tremor is hypertrophy of the inferior olivary nucleus which may be seen on brain MRI. When the syndrome is due to unilateral infarction of the dentate nucleus and superior cerebellar peduncle, changes in the olive appear on the contralateral side. Guillain and Mollaret postulated that disruption of the connections between the dentate and the contralateral olivary nucleus, which run via the red nucleus and central tegmental tract, is responsible for the syndrome. More recent studies have implicated interruption of a pathway from the deep cerebellar nuclei through the superior cerebellar peduncle, which then loops caudally through the central tegmental tract to the inferior olive. PVOs are characterized by: • Smooth, pendular movements occurring at a frequency of 1 to 3 Hz (typically 2 Hz). • PVOs are accentuated under closed lids • PVOs are synchronized with movements of the palate, facial muscles, pharynx, tongue, larynx and diaphragm. Conclusions from the analysis of eye movement recordings 1. PVOs are smooth rather than saccadic and have the velocity characteristics of normal convergence and divergence eye movements. Despite the absence of other components of the near triad (miosis and accommodation), the disorder retains certain features characteristic of normal vergence movements. 2. The eye movements are disjunctive, and furthermore the peak velocities achieved for various amplitudes are typical of normal vergence movements. 3. The pathological alterations resulting in PVO implicate a separately functioning, physiologically normal vergence system within the brainstem. 4. The continuous nature of PVOs distinguishes them from the nystagmus that occurs with Parinaud's syndrome, which is episodic and provoked by voluntary saccadic eye movements, especially attempted upgaze. 5. In cerebral Whipple's disease the abnormal eye movements have been ascribed to oscillations of the vergence system; hence the term pendular vergence oscillations. |
| Anatomy |
According to Guillain and Mollaret the crucial location for the lesion(s) producing palatal tremor is one that involves the dentato-olivary pathway through the superior cerebellar peduncle. This pathway is an interconnecting circuit connecting three brainstem nuclei - the dentate, the red nucleus and the inferior olivary nucleus. The lesion can be located in one of four places: 1. The dentate nucleus 2. The dentate outflow through the superior cerebellar peduncle 3. At the level of the red nucleus where the pathway passes dorsally and inferior to the contralateral red nucleus or 4. In the descending central tegmental tract to the contralateral inferior olivary nucleus. More recent studies have implicated interruption of a pathway from the deep cerebellar nuclei through the superior cerebellar peduncle, which then loops caudally through the central tegmental tract to the inferior olive. When the syndrome is due to unilateral infarction of the dentate nucleus and superior cerebellar peduncle, hypertrophic changes in the inferior olivary nucleus appear on the contralateral side, as in this patient with a cavitary infarct in the left brainstem and contralateral hypertrophy of the right inferior olivary nucleus. |
| Pathology |
Histologically, the olivary nucleus is enlarged, due to hypertrophy of neurons that contain increased acetylcholinesterase reaction product. Such changes begin within a month of the stroke and maximize in about six months, and are accompanied by astrocytosis, and synaptic and axonal remodeling. At the same time, the number of olivary neurons progressively declines, so that after six years, they are less than 10% of control brains. Also, both the myelin and the axons of efferent fibers from olivary neurons are severely degenerated in patients with persistent palatal tremor who survive several years. Despite the anatomic demonstration of atrophy, functional imaging studies suggest increased metabolism of the inferior olive. |
| Disease/Diagnosis |
Palatal tremor; Pontine Infarction. |
| Clinical |
This patient with oculopalatal tremor has striking pendular vertical oscillations (PVOs) in central gaze. The eye movements show: 1. Constant PVOs with eyes open and closed 2. A right horizontal gaze palsy 3. Intact horizontal gaze to the left 4. Intact vertical gaze 5. Intact convergence The recognition of vergence oscillations prompts the examiner to look immediately at the palate. The palatal tremor beats synchronously with convergence movements of the eyes. The term ‘tremor' is more accurate than "myoclonus", since the movements of affected muscles are to-and-fro, and are approximately synchronized, typically at a rate of about two cycles per second. PVOs may sometimes occur acutely with pontine infarctions that cause horizontal gaze palsy, but associated palatal movements usually do not develop for several weeks. PVOs are characterized by: • Smooth, pendular movements occurring at a frequency of 1 to 3 Hz (typically 2 Hz). • PVOs are accentuated under closed lids • PVOs are synchronized with movements of the palate, facial muscles, pharynx, tongue, larynx and diaphragm. Review ID923-1, ID927-1 alongside this case. Box 10-10 Clinical Features of Acquired Pendular Nystagmus Pg 506 (11). |
| Presenting Symptom |
Acute unsteadiness |
| Ocular Movements |
Palatal Tremor (Myoclonus); Pendular Vertical Oscillations; Unilateral Horizontal Gaze Palsy; Full Vertical Gaze |
| Neuroimaging |
MRI in two cases of palatal tremor are illustrated: Case 1: Figure 1. Axial NECT scan shows a large pontine hemorrhage extending to the midbrain in patient (ID936-4), who survived this massive hypertensive intracranial hemorrhage and 2 years later developed palatal tremor. Case 2: Figure 2. Axial T2WI in a patient who developed palatal tremor 6 months after a midbrain bleed from a cavernous malformation shows a small mixed signal intensity lesion in the dorsal midbrain tegmentum. Figure 3. Axial T2WI (same case as Fig. 2) shows enlarged olives with striking hyperintensity characteristic for classic hypertrophic olivary degeneration. Courtesy Anne Osborn, M.D. |
| Treatment |
Only rarely does oculopalatal tremor resolve spontaneously. Gabapentin, ceruletide, memantine, and anticholinergic agents may help some patients. Drugs that block connexin channels and there by reduce synchronized discharge of electronically coupled olivary neurons might provide a new therapeutic approach. |
| Etiology |
Pontine infarction |
| Supplementary Materials |
Palatal Tremor: https://collections.lib.utah.edu/details?id=2174223 Pendular Vertical Oscillations: https://collections.lib.utah.edu/details?id=2174230 |
| Date |
1978 |
| References |
1. Averbuch-Heller L, Tusa RJ, Fubry L, Rottach KG, Ganser GL, Heide W, Büttner U, Leigh RJ. A double-blind controlled study of gabapentin and baclofen as treatment for acquired nystagmus. Ann Neurol 1997;41:818-25. http://www.ncbi.nlm.nih.gov/pubmed/9189045 2. Barton JJ, Cox TA. Acquired pendular nystagmus in multiple sclerosis: clinical observations and the role of optic neuropathy. J Neurol Neurosurg Psychiatry. 1993 Mar;56(3):262-267. http://www.ncbi.nlm.nih.gov/pubmed/8459242 3. Dehaene I., Van Zandycke M, Appel B. Acquired pendular nystagmus. Neuro-ophthalmol 1987;7(5);297-300. 4. Deuschl G, Toro C, Valls-Solé J, Zeffiro T, Zee DS, Hallett M. Symptomatic and essential palatal tremor. 1. Clinical, physiological and MRI analysis. Brain. 1994 Aug;117 ( Pt 4):775-788. http://www.ncbi.nlm.nih.gov/pubmed/7922465 5. Dubinsky RM, Hallett M, Di Chiro G, Fulham M, Schwankhaus J. Increased glucose metabolism in the medulla of patients with palatal myoclonus. Neurology. 1991 Apr;41(4):557-562. http://www.ncbi.nlm.nih.gov/pubmed/2011257 6. Goyal M, Versnick E, Tuite P, Saint Cyr J, Kucharczyk W, Montanera W, Willinsky R, Mikulis D. Hypertrophic olivary degeneration: meta-analysis of the temporal evolution of MR findings. Am J Neuroradiol 2000; 21:1073-1077. http://www.ncbi.nlm.nih.gov/pubmed/10871017 7. Guillain G, Mollaret P. Deux cas myoclonies synchrones et rhythmées vélo-pharyngo-laryngo-oculodiaphragmatiques: Le problèm anatomique et physiolopathologique de ce syndrome. rev. Neurol (Paris) 1931;2:545-566. 8. Keane JR. Acute vertical ocular myoclonus. Neurology 1986;36:86-89. http://www.ncbi.nlm.nih.gov/pubmed/3941790 9. Koeppen AH. Olivary hypertrophy; histochemical demonstration of hydrolytic enzymes. Neurology 1980;30:471-480. http://www.ncbi.nlm.nih.gov/pubmed/6245389 10. Leigh RJ, Hong S, Zee DS, Optican LM. Oculopalatal tremor: clinical and computational study of a disorder of the inferior olive. Soc Neurosci Abstr 2005; 933.8. 11. Leigh RJ, Zee DS. Diagnosis of Nystagmus and Saccadic Intrusions. Chp 10:475-558. In: The Neurology of Eye Movements, 4th Edition. Oxford University Press, New York 2006. 12. Lopez LI, Bronstein AM, Gresty MA, Du Boulay EP, Rudge P. Clinical and MRI correlates in 27 patients with acquired pendular nystagmus. Brain. 1996 Apr;119 ( Pt 2):465-472. http://www.ncbi.nlm.nih.gov/pubmed/8800942 13. Nishie M, Yoshida Y, Hirata Y, Matsunaga M. Generation of symptomatic palatal tremor is not correlated with inferior olivary hypertrophy. Brain. 2002 Jun;125(Pt 6):1348-1357. http://www.ncbi.nlm.nih.gov/pubmed/12023323 14. Ruigrok TJ, deZeeuw CI, Vogel J. Hypertrophy of inferior olivary neurons : a degenerative regenerative or plasticity phenomenon. Eur J Morphol 1990 ;28 :224-239. http://www.ncbi.nlm.nih.gov/pubmed/2245132 15. Samuel M, Torun N, Tuite PJ, Sharpe JA, Lang AE. Progressive ataxia and palatal tremor (PAPT): clinical and MRI assessment with review of palatal tremors. Brain. 2004 Jun;127(Pt 6):1252-1268. Epub 2004 Apr 16. http://www.ncbi.nlm.nih.gov/pubmed/15090471 |
| Language |
eng |
| Format |
video/mp4 |
| Type |
Image/MovingImage |
| Source |
3/4" Umatic master videotape |
| Relation is Part of |
167-6, 923-1, 927-1,929-1, 936-4 |
| Collection |
Neuro-Ophthalmology Virtual Education Library: Shirley H. Wray Collection: https://novel.utah.edu/Wray/ |
| Publisher |
North American Neuro-Ophthalmology Society |
| Holding Institution |
Spencer S. Eccles Health Sciences Library, University of Utah |
| Rights Management |
Copyright 2002. For further information regarding the rights to this collection, please visit: https://NOVEL.utah.edu/about/copyright |
| ARK |
ark:/87278/s62g0k2w |
| Setname |
ehsl_novel_shw |
| ID |
188576 |
| Reference URL |
https://collections.lib.utah.edu/ark:/87278/s62g0k2w |
