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A rare case of bilateral dissociated hypotropia and unilateral dissociated esotropia
Short Reports A Rare Case of Bilateral Dissociated Hypotropia and Unilateral Dissociated Esotropia Digital video of the case is available in the online article at the Journal’s Web site at www.mosby.com/jaapos.
Marc F. Greenberg, MD, and Zane F. Pollard, MD
Dissociated hyperdeviations, as well as exodeviations and torsional ocular movements, are well described. A rare case of bilateral dissociated hypodeviation and esodeviation is presented. This occurred in a young child after undergoing an infectious neurologic insult and subsequent strabismus surgery for third nerve paresis. Dissociated strabismus is a well-known phenomenon that commonly includes an upward and outward drift of a nonfixing eye, often accompanied by extorsion and sometimes latent nystagmus. The movement occurs and then resolves in the nonfixing eye with little movement in the fixing eye and is thus “dissociated.”1,2 In all descriptions of dissociated strabismus, the vertical component of the nonfixing eye is hypertropic and the horizontal component is exotropic. Recently, we observed a case of dissociated strabismus in which either of the nonfixing eyes were intermittently hypotropic and one nonfixing eye was esotropic.
CASE REPORT A 13-month-old boy was admitted to a children’s hospital with fever and lethargy. He was noted to have a dilated right pupil, later diagnosed as part of a right third nerve palsy. Spinal fluid was cloudy but intracranial pressure was normal. Streptococcus pneumoniae grew from blood and spinal fluid. Magnetic resonance imaging during the next 2 weeks showed multifocal, small, gray- but predominantly white-matter enhancing lesions in both frontal hemispheres, thalami, and left superior centrum ovale, suggesting a multifocal cerebritis in addition to bacterial meningitis. Cortical atrophy was also noted. Brain stem auditory– evoked responses were severely abnormal. Mild to moderate hypotonic quadraparesis persisted, along with sensorineuronal hearing loss and partial right From the Pediatric Ophthalmology Section, Scottish Rite Children’s Medical Center, Atlanta, Georgia. Supported in part by a grant from the James Hall Foundation. Submitted September 7, 2000. Revisions accepted November 20, 2000. Reprint requests: Marc F. Greenberg, MD, 5455 Meridian Mark, Rd, Suite 220, Atlanta, GA 30342. J AAPOS 2001;5:123-5. Copyright © 2001 by the American Association for Pediatric Ophthalmology and Strabismus. 1091-8531/2001/$35.00 + 0 75/1/113316 doi:10.1067/mpa.2001.113316
Journal of AAPOS
third nerve palsy. At 19 months of age, the patient underwent cochlear implant surgery, along with right superior and right medial rectus resections and left lateral rectus recession. Three months after strabismus surgery, the patient showed depression of the nonfixing, or covered, eye on either side in the primary position (testing performed only at near because of poor distance attention). The downward movements of the nonfixing eye were slow, of variable amplitude, and dissociated from movement of the fixing eye. The hypotropia persisted while the nonfixing eye was covered and sometimes recovered spontaneously, usually after a blink. The left eye also intermittently showed a dissociated inward movement, sometimes with the hypotropia and occasionally alone. There was frequently no strabismus in the primary position, with dissociated movements occurring spontaneously at times. No nystagmus or torsional movements were noted. Otherwise, the speed, frequency, amplitude, and character of the strabismic movements appeared much as the common dissociated vertical deviation, except that the dissociated, deviated eye was hypotropic rather than hypertropic and the left eye occasionally esodeviated rather than exodeviated (Figures 1 and 2; also, see video in the online article at www.mosby.com/jaapos). Follow-up 2 years after surgery (patient’s age, 31⁄2 years) revealed essentially similar dissociated eye movements in the primary position, with mildly diminished amplitudes compared with previous measurements. Since surgery, the right eye has had a stable elevation deficiency, limited to about 20° above the midline. The child remained nonverbal and developmentally delayed, although he can walk and can understand some voice commands with his cochlear implant. The implant precludes further magnetic resonance imaging studies.
DISCUSSION Dissociated hyperdeviations, exodeviations, and torsional ocular deviations are all common, although poorly understood, strabismic eye movements. They are frequently seen in conjunction with congenital strabismus, which develops during the first 6 months of life, with the dissociated deviation coming to light months to years later.1,2 The movements of the nonfixing eye are “dissociated”
April 2001
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Journal of AAPOS Volume 5 Number 2 April 2001
FIG 1. Right hypotropia revealed after right eye was covered and then immediately uncovered.
FIG 2. Left hypotropia revealed after left eye was covered and then immediately uncovered.
from the contralateral eye and appear to “ignore” Hering’s law of equal innervation. Nevertheless, Guyton3 has recently proposed a complex theory by which multiple ductions and versions obeying Hering’s law act to block nystagmus, leaving residual dissociated deviations as byproducts. In the past, the hypertropia was emphasized in dissociative vertical deviation, although associated exo- and torsion movements were occasionally acknowledged. More recently, Wilson and McClatchey4 have suggested the term dissociated strabismus complex to describe the overall phenomenon. They note that the dissociative vertical, horizontal, and torsional components should be described and measured individually, along with the latent nystagmus.4 Unlike the well-known dissociated strabismus complex, our case is associated with acquired, noncongenital strabismus secondary to neurologic damage, and it shows dissociated hypo- and eso- eye movements. Although the character of the strabismic movements is similar to that of the common dissociated deviations, the setting is dissimilar, and we doubt there is any etiologic similarity. Nevertheless, we are unaware of previous descriptions of dissociated hypotropias, and present this case to add to the documented patterns of abnormal eye movements. The only remotely similar description of a dissociated hypotropic movement occurs in Bielschowsky’s phenomenon. In the setting of a dissociated vertical deviation, a neutral density filter before the fixing eye may induce the hyperdeviating nonfixing eye to move downward below the fixing eye, creating a dissociated small hypodeviation.1,2 However, this hypodeviation has not been explained, and, once again, our case bears little similarity to the common dissociated deviations.
Neurologic injury can sometimes be associated with skew vertical deviation. Both gaze-alternating, as well as periodic-alternating, skew deviations have been reported.5,6 Nevertheless, skew deviations are usually noted shortly after brain stem damage7 and not 9 months after injury, as in this case. Additionally, cases of alternating skew deviations changed vertical direction on left and right gaze or had periodic alternation and did not alternate with changes in fixation, as in this case. Lastly, a skew deviation is a true vertical deviation, obeying Hering’s law, and not dissociative in nature.7 The ocular movements noted in this case are thus distinct from previous descriptions of skew deviations. Some authors adhere to the convention of designating the hypertropic eye in a vertical deviation, even when the hypertropic eye is the fixing, nondeviating eye or when the hypotropic eye has muscular pathology. Although the etiology and mechanism for this case of dissociated strabismus may differ from that of the wellknown dissociative vertical deviation, the terms dissociated hypotropia and dissociated esotropia are necessary to clearly describe the pattern of eye movements. Terms for dissociative strabismus have always referred specifically to the dissociated eye. In summary, we describe dissociated hypotropia and esotropia, occurring in a toddler months after infectious neurologic injury and subsequent strabismus surgery. Although the character of the eye movements was similar to the common dissociated vertical deviation, the direction was opposite and the setting in which it occurred was in no way similar. Skew deviations described in similar settings are not dissociated in character. The dissociated hypotropia and esotropia thus represent a unique pattern of strabismic eye movements.
Journal of AAPOS Volume 5 Number 2 April 2001
Greenberg and Pollard 125
References 1. Parks MM, Mitchell PR. Dissociated vertical deviations. In: Tasman W, Jaeger EA, editors. Duane’s clinical ophthalmology. Vol 1, Chap 18. Philadelphia: Lippincott Williams and Wilkins; 1998. p. 1-6. 2. von Noorden GK. Binocular vision and ocular motility. 4th ed. St Louis: Mosby; 1990. p. 341-5. 3. Guyton DL. Dissociated vertical deviation: etiology, mechanism, and associated phenomena. J AAPOS 2000;4:131-44.
4. Wilson ME, McClatchey SK. Dissociated horizontal deviation. J Pediatr Ophthalmol Strabismus 1991;28:90-5. 5. Corbett JJ, Schatz NJ, Shults WT, Behrens M, Berry RG. Slowly alternating skew deviation: description of a pretectal syndrome in three patients. Ann Neurol 1981;10:540-6. 6. Mitchell JM, Smith JL, Quencer RM. Periodic alternating skew deviation. J Clin Neuroophthalmol 1981;1:5-8. 7. Keane JR. Ocular skew deviation: analysis of 100 cases. Arch Neurol 1975;32:185-90.
An Eye on the Arts – The Arts on the Eye I go to bed and dream of visiting a fortune teller. “What of the future?” I ask. And the woman answers, “That remains to be unseen” —Felix Pollak (from “Nocturne” in Tunnel Visions [writings of a poet going blind p 15)
Marc F. Greenberg, MD, and Zane F. Pollard, MD
Dissociated hyperdeviations, as well as exodeviations and torsional ocular movements, are well described. A rare case of bilateral dissociated hypodeviation and esodeviation is presented. This occurred in a young child after undergoing an infectious neurologic insult and subsequent strabismus surgery for third nerve paresis. Dissociated strabismus is a well-known phenomenon that commonly includes an upward and outward drift of a nonfixing eye, often accompanied by extorsion and sometimes latent nystagmus. The movement occurs and then resolves in the nonfixing eye with little movement in the fixing eye and is thus “dissociated.”1,2 In all descriptions of dissociated strabismus, the vertical component of the nonfixing eye is hypertropic and the horizontal component is exotropic. Recently, we observed a case of dissociated strabismus in which either of the nonfixing eyes were intermittently hypotropic and one nonfixing eye was esotropic.
CASE REPORT A 13-month-old boy was admitted to a children’s hospital with fever and lethargy. He was noted to have a dilated right pupil, later diagnosed as part of a right third nerve palsy. Spinal fluid was cloudy but intracranial pressure was normal. Streptococcus pneumoniae grew from blood and spinal fluid. Magnetic resonance imaging during the next 2 weeks showed multifocal, small, gray- but predominantly white-matter enhancing lesions in both frontal hemispheres, thalami, and left superior centrum ovale, suggesting a multifocal cerebritis in addition to bacterial meningitis. Cortical atrophy was also noted. Brain stem auditory– evoked responses were severely abnormal. Mild to moderate hypotonic quadraparesis persisted, along with sensorineuronal hearing loss and partial right From the Pediatric Ophthalmology Section, Scottish Rite Children’s Medical Center, Atlanta, Georgia. Supported in part by a grant from the James Hall Foundation. Submitted September 7, 2000. Revisions accepted November 20, 2000. Reprint requests: Marc F. Greenberg, MD, 5455 Meridian Mark, Rd, Suite 220, Atlanta, GA 30342. J AAPOS 2001;5:123-5. Copyright © 2001 by the American Association for Pediatric Ophthalmology and Strabismus. 1091-8531/2001/$35.00 + 0 75/1/113316 doi:10.1067/mpa.2001.113316
Journal of AAPOS
third nerve palsy. At 19 months of age, the patient underwent cochlear implant surgery, along with right superior and right medial rectus resections and left lateral rectus recession. Three months after strabismus surgery, the patient showed depression of the nonfixing, or covered, eye on either side in the primary position (testing performed only at near because of poor distance attention). The downward movements of the nonfixing eye were slow, of variable amplitude, and dissociated from movement of the fixing eye. The hypotropia persisted while the nonfixing eye was covered and sometimes recovered spontaneously, usually after a blink. The left eye also intermittently showed a dissociated inward movement, sometimes with the hypotropia and occasionally alone. There was frequently no strabismus in the primary position, with dissociated movements occurring spontaneously at times. No nystagmus or torsional movements were noted. Otherwise, the speed, frequency, amplitude, and character of the strabismic movements appeared much as the common dissociated vertical deviation, except that the dissociated, deviated eye was hypotropic rather than hypertropic and the left eye occasionally esodeviated rather than exodeviated (Figures 1 and 2; also, see video in the online article at www.mosby.com/jaapos). Follow-up 2 years after surgery (patient’s age, 31⁄2 years) revealed essentially similar dissociated eye movements in the primary position, with mildly diminished amplitudes compared with previous measurements. Since surgery, the right eye has had a stable elevation deficiency, limited to about 20° above the midline. The child remained nonverbal and developmentally delayed, although he can walk and can understand some voice commands with his cochlear implant. The implant precludes further magnetic resonance imaging studies.
DISCUSSION Dissociated hyperdeviations, exodeviations, and torsional ocular deviations are all common, although poorly understood, strabismic eye movements. They are frequently seen in conjunction with congenital strabismus, which develops during the first 6 months of life, with the dissociated deviation coming to light months to years later.1,2 The movements of the nonfixing eye are “dissociated”
April 2001
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Greenberg and Pollard
Journal of AAPOS Volume 5 Number 2 April 2001
FIG 1. Right hypotropia revealed after right eye was covered and then immediately uncovered.
FIG 2. Left hypotropia revealed after left eye was covered and then immediately uncovered.
from the contralateral eye and appear to “ignore” Hering’s law of equal innervation. Nevertheless, Guyton3 has recently proposed a complex theory by which multiple ductions and versions obeying Hering’s law act to block nystagmus, leaving residual dissociated deviations as byproducts. In the past, the hypertropia was emphasized in dissociative vertical deviation, although associated exo- and torsion movements were occasionally acknowledged. More recently, Wilson and McClatchey4 have suggested the term dissociated strabismus complex to describe the overall phenomenon. They note that the dissociative vertical, horizontal, and torsional components should be described and measured individually, along with the latent nystagmus.4 Unlike the well-known dissociated strabismus complex, our case is associated with acquired, noncongenital strabismus secondary to neurologic damage, and it shows dissociated hypo- and eso- eye movements. Although the character of the strabismic movements is similar to that of the common dissociated deviations, the setting is dissimilar, and we doubt there is any etiologic similarity. Nevertheless, we are unaware of previous descriptions of dissociated hypotropias, and present this case to add to the documented patterns of abnormal eye movements. The only remotely similar description of a dissociated hypotropic movement occurs in Bielschowsky’s phenomenon. In the setting of a dissociated vertical deviation, a neutral density filter before the fixing eye may induce the hyperdeviating nonfixing eye to move downward below the fixing eye, creating a dissociated small hypodeviation.1,2 However, this hypodeviation has not been explained, and, once again, our case bears little similarity to the common dissociated deviations.
Neurologic injury can sometimes be associated with skew vertical deviation. Both gaze-alternating, as well as periodic-alternating, skew deviations have been reported.5,6 Nevertheless, skew deviations are usually noted shortly after brain stem damage7 and not 9 months after injury, as in this case. Additionally, cases of alternating skew deviations changed vertical direction on left and right gaze or had periodic alternation and did not alternate with changes in fixation, as in this case. Lastly, a skew deviation is a true vertical deviation, obeying Hering’s law, and not dissociative in nature.7 The ocular movements noted in this case are thus distinct from previous descriptions of skew deviations. Some authors adhere to the convention of designating the hypertropic eye in a vertical deviation, even when the hypertropic eye is the fixing, nondeviating eye or when the hypotropic eye has muscular pathology. Although the etiology and mechanism for this case of dissociated strabismus may differ from that of the wellknown dissociative vertical deviation, the terms dissociated hypotropia and dissociated esotropia are necessary to clearly describe the pattern of eye movements. Terms for dissociative strabismus have always referred specifically to the dissociated eye. In summary, we describe dissociated hypotropia and esotropia, occurring in a toddler months after infectious neurologic injury and subsequent strabismus surgery. Although the character of the eye movements was similar to the common dissociated vertical deviation, the direction was opposite and the setting in which it occurred was in no way similar. Skew deviations described in similar settings are not dissociated in character. The dissociated hypotropia and esotropia thus represent a unique pattern of strabismic eye movements.
Journal of AAPOS Volume 5 Number 2 April 2001
Greenberg and Pollard 125
References 1. Parks MM, Mitchell PR. Dissociated vertical deviations. In: Tasman W, Jaeger EA, editors. Duane’s clinical ophthalmology. Vol 1, Chap 18. Philadelphia: Lippincott Williams and Wilkins; 1998. p. 1-6. 2. von Noorden GK. Binocular vision and ocular motility. 4th ed. St Louis: Mosby; 1990. p. 341-5. 3. Guyton DL. Dissociated vertical deviation: etiology, mechanism, and associated phenomena. J AAPOS 2000;4:131-44.
4. Wilson ME, McClatchey SK. Dissociated horizontal deviation. J Pediatr Ophthalmol Strabismus 1991;28:90-5. 5. Corbett JJ, Schatz NJ, Shults WT, Behrens M, Berry RG. Slowly alternating skew deviation: description of a pretectal syndrome in three patients. Ann Neurol 1981;10:540-6. 6. Mitchell JM, Smith JL, Quencer RM. Periodic alternating skew deviation. J Clin Neuroophthalmol 1981;1:5-8. 7. Keane JR. Ocular skew deviation: analysis of 100 cases. Arch Neurol 1975;32:185-90.
An Eye on the Arts – The Arts on the Eye I go to bed and dream of visiting a fortune teller. “What of the future?” I ask. And the woman answers, “That remains to be unseen” —Felix Pollak (from “Nocturne” in Tunnel Visions [writings of a poet going blind p 15)