Downbeat Nystagmus

Update Item Information
Identifier 170-53
Title Downbeat Nystagmus
Creator Shirley H. Wray, MD, PhD, FRCP
Affiliation (SHW) Professor of Neurology, Harvard Medical School; Director, Unit for Neurovisual Disorders, Massachusetts General Hospital, Boston, Massachusetts
Subject Downbeat Nystagmus; Oscillopsia; Chiari-1 Malformation; Primary Position Downbeat Nystagmus
History In 1984, this young woman was involved in a motor vehicle accident when her car was hit from behind. She struck her head on the dash board but had no loss of consciousness. She was able to get out of the car unaided and was immediately aware of pain in her neck. She thought that she had sustained a whiplash injury. At that time, she did not go to the hospital and instead drove home. The next day she had severe post-traumatic headache. She went to her local hospital emergency room for evaluation of the following symptoms. • Headache • A sensation of light headedness • Pain and stiffness in the neck • Blurred vision and oscillopsia with the visual world moving up and down • Mild unsteadiness walking Diagnosis: Post-traumatic Type I Chiari Malformation The patient was referred to the Neurovisual Clinic at the Massachusetts General Hospital. Neuro-ophthalmological examination: Visual acuity of 20/30 OU Normal pupil reflexes and fundus examination Full eye movements OU Prominent downbeat nystagmus in primary gaze Large amplitude downbeat nystagmus on gaze to the left greater than to the right Full up gaze with no nystagmus Full down gaze with small amplitude downbeating nystagmus. Disturbances of Eye Movements in Type I Chiari Malformation include: 1. Downbeat nystagmus 2. Divergence nystagmus 3. Convergence nystagmus 4. Periodic alternating nystagmus 5. Gaze-evoked nystagmus 6. Rebound nystagmus 7. Seesaw nystagmus 8. Internuclear ophthalmoplegia 9. Positional nystagmus Table 12-1 Disturbances in Eye Movements in the Arnold- Chiari Malformation. Pg 610 (8)
Disease/Diagnosis Post-traumatic Type I Chiari malformation; Downbeat Nystagmus
Clinical This patient with Type I Chiari malformation had: • Downbeat nystagmus with the eyes in central position • Large amplitude downbeat nystagmus on gaze to the left greater than to right • Full upgaze with no nystagmus • Full downgaze with few beats of small amplitude downbeating nystagmus • Convergence suppressed the nystagmus Box 10-2 Clinical Features of Downbeat Nystagmus Pg 484 (8). There are three forms of nystagmus caused by lesions affecting the central vestibular pathways: 1. Downbeat nystagmus 2. Upbeat nystagmus 3. Torsional nystagmus Downbeat nystagmus is caused by a central vestibular imbalance due to lesions of the vestibulocerebellum, especially the flocculus and paraflocculus and brainstem pathways. The Purkinje cells of the flocculus preferentially discharge for downward movements and it has been suggested that there is an underlying upward eye velocity bias in the central vestibular or pursuit system or in the peripheral vestibular system which is normally inhibited by the cerebellum. With lesions of the vestibulocerebellum, cerebellar inhibition is disrupted and the upward bias uncovered, resulting in spontaneous downbeat nystagmus. Downbeat nystagmus in cerebellar cases may be modified by a number of factors, including orbital position, head position and movement, head shaking and caloric stimulation. Table 10-1 Etiology of Downbeat Nystagmus, Pg 482 (8). Downbeat nystagmus is occasionally disjunctive, being more vertical in one eye and torsional in the other. Downbeat nystagmus may be suppressed, or converted to upbeat nystagmus, by potassium channel blockers such as 3,4-diaminopyridine and 4-aminopyridine.
Presenting Symptom Post-traumatic headache
Ocular Movements Downbeat Nystagmus
Neuroimaging MRI with sagittal views of the cranio-cervical junction in Type I Chiari malformation has a highly characteristic radiologic profile, particularly on T1-weighted MRI which shows the low-lying cerebellar tonsils below the foramen magnum and behind the upper cervical cord. Neuroimaging studies were not available in this patient. Illustrative images in another case are shown here. Figure 1. Sagittal T1WI shows a classic Chiari I malformation with "peglike" tonsils extending inferiorly through the foramen magnum. Figure 2. Sagittal T2WI shows exquisite detail of the low-lying tonsils. Note vertically-oriented cerebellar folia. There is no associated syrinx in this case. Figure 3. Sagittal FLAIR shows no signal abnormality in either the tonsils or medulla. Courtesy Anne Osborn, M.D.
Treatment The treatment of a Chiari malformation is far from satisfactory. If clinical progression is slight or uncertain, it is probably best to do nothing. If progression is certain and disability is increasing, upper cervical laminectomy and enlargement of the foramen magnum are indicated.
Etiology Developmental anomaly
Supplementary Materials Chiari-1 Malformation: https://collections.lib.utah.edu/details?id=2174188
Date 1984
References 1. Albers FW, Ingels KJ. Otoneurological manifestations in Chiari-I malformation. J. Laryngol Otol 1993;107:441-443. http://www.ncbi.nlm.nih.gov/pubmed/8326227 2. Arnold AC, Baloh RW, Yee RD, Helper RS. Internuclear ophthalmoplegia in the Chiari type II malformation. Neurology 1990;40:1850-1854. http://www.ncbi.nlm.nih.gov/pubmed/2247233 3. Baloh RW, Yee RD. Spontaneous vertical nystagmus. Rev Neurol (Paris) 1989;145:527-532. http://www.ncbi.nlm.nih.gov/pubmed/2682931 4. Bosley TM, Cohen DA, Schatz NJ. Zimmerman RA, Bilaniuk LT, Savino PJ, Sergott RS. Comparison of metrizamide computed tomography and magnetic resonance imaging in the evaluation of lesions at the cerviomedullary junction. Neurology 1985;35:485-492. http://www.ncbi.nlm.nih.gov/pubmed/3982633 5. Cogan DG. Downbeat nystagmus. Arch Ophthalmol 1968;80:757-768. 6. Dones J. De Jesus O, Cohen CB, Toledo MM, Delgado M. Clinical outcomes in patients with Chiari I malformation a review of 27 cases. Surg Neurol 2003;60:142-147. http://www.ncbi.nlm.nih.gov/pubmed/12900124 7. Halmagyi GM, Rudge P, Gresty MA, Sanders MD. Downbeating nystagmus: a review of 62 cases. Arch Neurol 1983;40:777-784. http://www.ncbi.nlm.nih.gov/pubmed/6639406 8. Leigh RJ, Zee DS. Diagnosis of Nystagmus and Saccadic Intrusion. Chp10 475-558 and Chp 12 598-718. In: The Neurology of Eye Movements. 4th Ed. Oxford University Press, New York 2006. 9. Mossman SS, Bronstein AM, Gresty MA, Kendall B, Rudge P. Convergence nystagmus associated with Arnold-Chiari malformation. Arch Neurol 1990;47:357-359. http://www.ncbi.nlm.nih.gov/pubmed/2310320 10. Pedersen RA, Troost BT, Abel LA, Zorub D. Intermittent downbeat nystagmus and oscillopsia reversed by suboccipital craniectomy. Neurology 1980;30:1239-1242. http://www.ncbi.nlm.nih.gov/pubmed/7191521 11. Pujol J, Roig C, Capdevila A, Pou A, Marti-Vilalta JL, Kulisevsky J, Escartin A, Zannoli G. Motion of the cerebellar tonsils in Chiari type I malformation studies by cine phase-contrast MRI. Neurology 1995;45:1746-1753. http://www.ncbi.nlm.nih.gov/pubmed/7675239 12. Spooner JW, Baloh RW. Arnold-Chiari malformation. Improvement in eye movements after surgical treatment. Brain 1981; 104:51-60. http://www.ncbi.nlm.nih.gov/pubmed/7470844 13. Straumann D, Müller E. Torsional rebound nystagmus in a patient with type I Chiari malformation. Neuro-ophthalmology 1994;14:79-84. 14. Zee DS, Friendlich AR, Robinson DA. The mechanism of downbeat nystagmus. Arch Neurol 1974;30:227-237. http://www.ncbi.nlm.nih.gov/pubmed/4591431 15. Zimmerman CF, Roach ES, Troost BT. See-saw nystagmus associated with Chiari malformation. Arch Neurol 1986;43:299-300. http://www.ncbi.nlm.nih.gov/pubmed/3947282
Language eng
Format video/mp4
Type Image/MovingImage
Source 16 mm Film
Relation is Part of 3-3, 919-1, 922-5, 927-2
Collection Neuro-Ophthalmology Virtual Education Library - Shirley H. Wray Neuro-Ophthalmology 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/s6zd10hf
Setname ehsl_novel_shw
ID 188631
Reference URL https://collections.lib.utah.edu/ark:/87278/s6zd10hf