Congenital Nystagmus: Blurred vision

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Identifier 938-4
Title Congenital Nystagmus: Blurred vision
Creator Shirley H. Wray, MD, PhD, FRCP
Contributors Ray Balhorn, Video Compressionist; Steve Smith, Videographer
Affiliation (SHW) Professor of Neurology, Harvard Medical School; Director, Unit for Neurovisual Disorders, Massachusetts General Hospital, Boston, Massachusetts
Subject Congenital Nystagmus; Horizontal Jerk Nystagmus; Optokinetic Nystagmus Absent; Infantile Nystagmus Syndrome; Oscillopsia
History This 34 year old physician has had a life long problem with congenital nystagmus. He was an orphan and his adopted parents took him to see a pediatrician when he was very small. A missed diagnosis of a "lazy eye" was made. Subsequently, at the age of 9, when he complained of intermittent blurred vision, he saw an optometrist. Diagnosis: Congenital motor nystagmus In high school he did very well and passed the school vision tests and played games including baseball. Oscillopsia He had always experienced occasional oscillopsia and, following a serious hand infection treated with gentamycin at age 25, the oscillopsia became worse when he was in motion. He also felt that his balance had never been quite stable since that infection, and he had given up hiking for fear of falling. Neuro-ophthalmological examination: Visual acuity: OD: 20/60 monocularly, reads J1+ OS: 20/60, J1 At distance 20/30 OU binocular Visual fields, pupils and fundi normal. Ocular motility: Full eye movements OU Head turn to the right In head straight gaze, large amplitude right beating nystagmus Null position eyes 30 degrees to the left with his head turned an equal 30 to 40 degrees to the right. In the null position eyes almost stable and then as he looked from left gaze to right gaze right beating nystagmus and when he looked to the left, left beating nystagmus Covering each eye no latent nystagmus Horizontal nystagmus persisted in vertical up and downgaze Convergence suppressed the nystagmus The eyes are almost stationary in full convergence OKN nystagmus could not be superimposed even when tested with the eyes in the null position Consultation: Soon after I saw this patient I met Dr. John Leigh at the American Neurological Association Meeting in Washington and I discussed this patient's case with him. One of the unusual features of his case is the presence of oscillopsia and it turns out that Dr. Dell'Osso has only seen six cases of congenital nystagmus with oscillopsia. Dr. Leigh offered to see this patient free of charge and record his eye movements. Fortunately, the patient gladly accepted the offer and he went to Case Western Reserve University in February 1996 to be studied. Dr.John Leigh, Dr. Dell'Osso, and Dr. Lea Averbuch-Heller evaluated the patient. They measured horizontal, vertical and torsional rotation of his eyes by the search coil method. He was found to have: 1. Predominantly right-beating nystagmus, with a smaller clockwise-beating torsional component and a very small vertical see-saw component, all at 4 Hertz. 2. His nystagmus did not change when one eye or the other viewed. 3. He had a relative null when the eyes were turned about 30 degrees to his left, beyond that, it reversed. 4. He did not have well developed foveation periods except when his nystagmus reversed on far left gaze (the position in which he preferred to view). 5. Convergence reversed and suppressed his nystagmus; it almost stopped when he converged to 21 degrees, and turned to the left (right eye turned to left 19 degrees, left eye turned to left 2 degrees). 6. Otherwise, his saccades and pursuit in both horizontal and vertical planes were only remarkable for superimposed nystagmus. 7. His vestibulo-ocular reflex did not have a reduced gain; in darkness, it was about 0.75. 8. With rapid head turns, while fixating (Michael Halmagyi's test), the gain was 0.85. 9. His nystagmus in darkness increased when he attempted to view an imaginary target (‘"fixation effort"). Opinion: The three investigators concluded that: The patient had congenital horizontal jerk nystagmus that suppressed at near and on left gaze. Treatment: He tried on some base-out prisms, and these seemed to help. They recommended that he be fitted with glasses that contain his present prescription plus 7.00 diopter base-out prisms with -1.00 diopter spheres added to compensate for accommodation; for best effect, the lenses should be side-coated. Dr. Leigh provided him with JC's account of "Living without a balancing mechanism" and advised him to take regular walks and other light exercise. The only other thought was that because he had a small see-saw component to his nystagmus, an MRI scan (with views of the parasellar region and also the craniocervical junction) might be considered, if not already done. (MRI was normal). The history of oscillopsia with motion was an additional complication due to a toxic vestibulopathy secondary to his gentamycin therapy.
Disease/Diagnosis Infantile Nystagmus Syndrome
Clinical This patient with the infantile nystagmus syndrome has: • Sits with a right head turn • Eyes deviated approximately 30 degrees to the left in their best null position. He gives a • Description of intermittent oscillopsia on gaze left, worse in primary gaze and • Oscillopsia suppressed when reading in • Primary gaze large amplitude right beating nystagmus • Right gaze, right beating nystagmus • Left gaze, left beating nystagmus • Unable to superimpose optokinetic nystagmus • Lid nystagmus eyes closed • Smooth pursuit interrupted by nystagmus • Primary position nystagmus is worse in the dark prompting the patient to give up night driving Covering each eye in turn, one could not be certain that he had latent nystagmus. No latent nystagmus was detected however on eye movement recording. Classification: The Classification of Eye Movement Abnormalities and Strabismus Working Group has recommended new names for nystagmus that begins during infancy. Three categories have been defined: 1. Infantile Nystagmus Syndrome (INS), which corresponds to what had previously been called motor or sensory forms of congenital nystagmus. 2. Fusional Maldevelopment Nystagmus Syndrome (FMNS), which corresponds to latent nystagmus occurring in association with amblyopia and strabismus and 3. Spasmus Nutans Syndrome (SNS). Diagnostic features of each of these syndromes are summarized in (ref 8). Box 10-11 Clinical features of Infantile Nystagmus Syndrome (See Chp 10, p513) Box 10-12 Clinical features of Latent Nystagmus (FMNS) (See Ch 10 p517) Box 10-13 Clinical features of Spasmus Nutans Syndrome (See Chp 10 p519) The congenital ‘nystagmus' of INS maybe present at birth but usually develops during infancy. Although variable in wave form (the commonest are increasing-velocity and pendular), certain clinical features usually differentiate INS from other ocular oscillations. • INS is almost always conjugate and mainly horizontal, even on up or downgaze. • A torsional component to the nystagmus is probably common but may be difficult to identify clinically as in this case. • Less commonly the nystagmus of INS is mainly seesaw and such patients may have underlying disease of the retina, visual pathways or cerebellum. • Life long nystagmus that is vertical is not typical of INS, and consideration should be given to other diagnoses such as the calcium channelopathies. • Nystagmus of INS is usually accentuated by the attempt to fixate on an object, and by attention or anxiety. • Eyelid closure or convergence, usually suppress it, but occasionally the nystagmus is evoked by viewing a near target. • Often nystagmus decreases when the eyes are moved into a particular position in the orbit; this is called the null point or zone, and corresponds to the range of eye position within which slow-phase eye velocity is at a minimum. • In some patients, especially albinos, the nystagmus periodically reverses direction, but this reversal seldom occurs in the regular manner seen in the acquired form of PAN. Stereovision: is usually degraded, even in children lacking strabismus, partly due to retinal image motion. Head turns: Head turns are common in INS and are used to bring the eye and the orbit close to the null point or zone, which nystagmus is minimal. The presence of such head turns in childhood photographs is often useful evidence in diagnosing INS. Nystagmus blockage syndrome: Another strategy used by patients with either INS or the latent nystagmus of FMNS is to purposely induce an esotropia (nystagmus blockage syndrome) in order to suppress the nystagmus; such an esotropia requires a head turn to direct the viewing eye at the object of interest. Head oscillations: Some patients with INS also show head oscillations. Such head movements are not compensatory and tend to increase when the individual attends to an object, an effort that also increases the nystagmus. It seems possible, therefore, that in most patients head tremor and ocular oscillations represent the output of a common neural mechanism. Associated visual system defects: Overall, most patients with congenital forms of nystagmus have no associated visual system defects. (See Table 10-7 Visual system disorders associated with INS Chp 10 p513. (ref 8)). Familial INS: INS either, with or without associated visual system abnormalities may be familial. Autosomal dominant, and sex-linked recessive forms of inheritance have been reported. In x-linked forms, the mother may show subtle ocular motor abnormalities. The hereditary forms of INS, with the characteristic wave forms should be differentiated from other genetic disorders that produce forms of nystagmus typical of cerebellar dysfunction. (See ID 163-9-4)
Presenting Symptom Blurred vision
Ocular Movements Congenital Nystagmus; Horizontal Jerk Nystagmus; Optokinetic Nystagmus Absent; Infantile Nystagmus Syndrome
Treatment Surgical procedures for congenital nystagmus are discussed in ref 8.
Etiology Congenital
Date 1995
References 1. Abadi RV, Dickinson CM. Waveform characteristics in congenital nystagmus. Documents Ophthalmologica 1986;64:153-167. http://www.ncbi.nlm.nih.gov/pubmed/3608756 2. Abel, L.A., Wang, Z.I. and Dell'Osso, L.F.: Wavelet Analysis in Infantile Nystagmus Syndrome: Limitations and Abilities. Invest. Ophthalmol. Vis. Sci. 2008. (In Press). http://www.ncbi.nlm.nih.gov/pubmed/18450585 3. Averbuch-Heller L, Dell'Osso LF, Leigh RJ, Jacobs JB, Stahl JS. The torsional component of ‘horizontal' congenital nystagmus. J Neuro-ophthalmol 2002;22:22-32. http://www.ncbi.nlm.nih.gov/pubmed/11937902 4. Classification of Eye Movement Abnormalities and Strabismus (CEMAS) Working Group. http://www.nei.nih.gove/news/statements/cemas 2003. 5. Cogan D. Neurology of the Ocular Muscles, 2nd Edition. Charles C. Thomas Publisher, Springfield, Ill. 1956. 6. Hertle RW, Maldanado VK, Maybodi M, Yang D. Clinical and ocular motor analysis of the infantile nystagmus syndrome in the first 6 months of life. Br J Ophthalmol 2002;86:670-675. http://www.ncbi.nlm.nih.gov/pubmed/12034691 7. Hertle RW, Maybodi M, Mellow SD, Yang D. Clinical and oculographic response to Tenuate Dospan (diethylpropionate) in a patient with congenital nystagmus. Am J Ophthalmol 2002;133:159-160. http://www.ncbi.nlm.nih.gov/pubmed/11755862 8. Leigh JR, Zee DS. Diagnosis of Nystagmus and Saccadic Instrusions. Chp 10, 475-558. In: The Neurology of Eye Movements, Fourth Edition. Oxford University Press, NY 2006. 9. Shibasaki H, Motomura S. Suppression of congenital nystagmus. J Neurol Neurosurg Psychiatry 1978;41:1078-1083. http://www.ncbi.nlm.nih.gov/pubmed/731252 10. Stevens DJ, Hertle RW. Relationships between visual acuity and anomalous head posture in patients with congenital nystagmus. J Pediatr Ophthalmol Strabismus 2003;40:259-264. http://www.ncbi.nlm.nih.gov/pubmed/14560831
Language eng
Format video/mp4
Type Image/MovingImage
Source 3/4" Umatic master videotape
Relation is Part of 163-9-1, 163-9-2, 163-9-3, 163-9-4, 169-28, 907-2, 936-6, 944-8
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/s6v72g6x
Setname ehsl_novel_shw
ID 188508
Reference URL https://collections.lib.utah.edu/ark:/87278/s6v72g6x