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Show Journal of Clinical Neuro-ophthalmology 7(1): 29-33, 1987. Isolated Environmental Tilt Associated with Lateral Medullary Compression by Dolichoectasia of the Vertebral Artery Is There a Cause and Effect Relationship? Michael L. Slavin, M.D., and Ronald J. LoPinto, M.D. '9 1987 Raven Press, New York An elderly woman with the persistent isolated symptom of monocular and binocular tilting of environmental objects, was found on magnetic resonance imaging to have compression of the lateral medulla by an ectatic vertebral artery, The double Maddox rod test showed no relative torsion of either globe although 5° of right excyclotorsion and left incyclotorsion (rightward ocular counter-rolling) was detected on testing with monocular viewing, There was no accompanying hyperdeviation, nystagmus or other neurologic signs, Symmetrical tilting of each globe associated with head tilt and skew deviation (the ocular tilt reflex) may be caused by lesions involving otolith connections. Isolated environmental tilt may herald the onset of lateral medullary infarction (Wallenberg's syndrome), or may be associated with vertebro-basilar insufficiency. Could compression of otolith connections in the medulla cause persistent ocular counter-rolling without accompanying neurologic signs? Key Words: Dolichoectasia-Environmental tilt-Ocular counterrolling-Ocular tilt reflex-Otolith. From the Division of Neuro-ophthalmology, Department of Ophthalmology, Long Island Jewish Medical Center, New Hyde Park, New York (M.L.S.) and the School of Medicine, Health Sciences Center, State University of New York at Stony Brook, Stony Brook, New York (R.J.L.). Address correspondence and reprint requests to Dr. Michael Slavin, Division of Neuro-ophthalmology, Department of Ophthalmology, Long Island Jewish Medical Center, New Hyde Park, NY 11042, U.S.A. Presented at the Frank Walsh Society, 18th Annual Meeting, Seattle, Washington, on February 21, 1986. 29 The symptom of environmental tilt, unassociated with diplopia or other neurologic disturbance, is unusual, and may cause the examiner to dismiss it as functional. In Wallenberg's syndrome (lateral medullary infarction) (1,2), bizarre, rather transient, complaints of environmental tilt (at times 90° or 180°) often herald the onset of skew deviation, nystagmus, ipsilateral face and contralateral body hemisensory defect, Horner's syndrome, and ocular lateropulsion. In addition, Ropper (3) in 1983 reported four patients who had the illusion that their visual surroundings were tilting, along with associative neurologic disturbances suggestive of brainstem ischemia. The symptom of visual tilt lasted only seconds to minutes in three cases and "sometime within one hour" in the fourth. We report a patient who experienced acute onset of isolated but persistent counterclockwise tilt of the environment, perceived both binocularly and monocularly with either eye. Magnetic resonance imaging (MRI) revealed dolichoectasia of the left vertebral artery producing extrinsic compression of the anterolateral medulla, CASE REPORT A 66-year-old woman was well until August 1985 when, while sitting in a movie theater, she perceived objects on the screen to be minimally tilted in a counterclockwise (leftward) direction. Closing either eye or tilting the head or body did not change this sensation. Near objects did not appear to be tilted. There was no associated diplopia, vertigo, weakness, face or body numbness, oscillopsia, or other neurologic symptoms. Past medical history revealed hypertension and 30 M. L. SLAVIN AND R. J. LoPINTO questionable rheumatoid arthritis. The patient had undergone surgery for a parathyroid adenoma in 1967 and for an aortic aneurysm in 1979. The symptom of leftward tilt persisted without change. Neuro-ophthalmologic examination on November 8, 1985 revealed moderate rightward head tilt with poor passive head movement. This had been statedly present for many years and was secondary to cervical arthritis. Visual acuity was normal. Extraocular movements were normal and there was no hyperdeviation in any field of gaze or on head tilt to either side. No nystagmus was noted and saccades were normal and symmetrical to each side. Eyelids and pupils were normal. The patient drew a sketch of the door in the examination room. The vertical edges of the door were seen to have a distinct counterclockwise slant. Double Maddox rod test (with a 4PD base down prism in front of the right eye to create two vertically separated horizontal lines) revealed no relative torsion of each globe. When a horizontal Maddox rod was placed monocularly (in front of either eye with the fellow eye occluded) the patient noted a vertical line (at times, a line with a slight, immeasurable, counterclockwise slant). The tangent screen visual field wand was then held vertically (lined up with one edge of the door) at a distance of 15 feet. The patient per-ceived this to be tilted counterclockwise, when viewed with either eye alone. It was then rotated clockwise until she perceived it as being perfectly vertical and the angle of cyclodeviation was measured (Fig. 1). Five degrees of right excyclotorsion and five degrees of left incyclotorsion were present. The patient's visual fields were normal, except that the right blind spot was slightly infraplaced and the left one was supra-placed. Optic discs were normal and fundus photography (with the head maintained as straight as possible) clearly showed the right optic disc to be supra-placed and the left infra-placed compared to each macula (Fig. 2). Results of a neurologic examination were normal, including the absence of spontaneous nystagmus while wearing a +20.00 diopter lens over each eye, or induction of nystagmus during the Hallpike maneuver. Near vision remained normal during head shaking. Electronystagmography revealed normal saccades, pursuit, and optokinetic nystagmus. There was no nystagmus when the patient's eyes were closed and no directional preponderance was present on bithermal caloric testing. MRI was performed and revealed compression of the anterolateral medulla by a dolichoectatic left vertebral artery (Fig. 3). FIG. 1. The visual field ~and (arrows) lined up with one vertical edge of the door (left) was perceived by the patient to have a leftward tilt. When the wand was rotated approximately 5° clockwise (right), it was perceived as being spatially vertical. I ClIII NCIlYO-"I,hthalllllll, Vol. 7, No.1, 1987 /'-"" .' FI(i, 2. Fl.Il'l<!llsphotograph.ofthe -leneYe.dernon~tratihg.incYCiotorsjor'l<The macula, whifh wiltnorc 'mallyjineupwiththeiMerior tt1irdoLtheoptlcdisc;fs;seen tobe·supra-placecl(~rrmW).·., - ... -.' - - '-,.-.,.. ' '-. - .. -" '" '--. -" j. . ••," ;"; .,., - '. , . ·---- -'-,. ,,-, ," ,- . --- ,"'. " ' .. ' ,'- " ~,:';', .":::_:~':'::::,: ':~">':':', ::, - lJISCU~SI()~?·· - ......•............ '., _,,', ',' ;:~y.asth(>hia grav\siand•••n?!Yebf)5patients~ith ,!iag~()sed •••skewdeviationihaci.ol1j~{~tive ••••torsional .':ciip19Pi:il •.•of ••.5o•••••oLiIllore.iFou!·of-follr. p~tiertts . (lOP%)With15°iof cyclode.viatibh;,12of14 patients ··(S6%J""ith 10° of cyclodeviatiori,. andJ10f21 pac ti~.ri!s· {55.%)>>,.ith5°ofcY¢16de_Yiation-wel"e..a~are of-erivifolimenlaliilt with 'normalbiiiocll1ar' vieiVing.:.I)l()-patient:~~~~ve.U:·ha:dc)rdo;otaii sympt9n,:s With-monOCUlar viewing. -.> ". '..' Tne' t?~.sicmofi~acl1g!ob~ in ouS f)ati~rtt,however, ':Yas:syni!Jl.e.tricci] and therefoi~ no-WClooeviati6n was-elidtedon'the-double'~Mada6x:rod. test. Rela tiv~-ye~ftical tr~nsposi tion'6f" the optic disc comf?a!e~j:oe::a.chni?t:ula on -fundusf'~6fog~ ~aphy, aloflg\¥ithJhec()rt~spondingshiftofthe-._ .blind ~potonyisllal fiel(is, .corrohoratedtight .,/; ..counttO'r,:rQllil1gof/eath,globe: Cautl0n/sh()u1et be u:sed_.in.·interpretingfundus·photQgraph~aIldvi•.~ suaL fieldsinpredictingcic·u)ar.• counter-rolIil1g, , .•.. l"I()\Vt?ver,_ashead.tiltfrom·\Vhate·verreasonalone•••.·• ~ciy.I~adto •• false •• positiv(ri~~lt~.jhus. in ••Olupa- •. M. L. SLAVIN AND R. f. LoPINTO FIG. 3. Axial MRI (A and B, T1 weighted image; C, T2 weighted image) showing leftward displacement of medulla (black arrow) by an ectatic left vertebral artery (white arrow, arrowhead). Note the absence of signal from the vertebral artery (arrowhead) surrounded by strong signal from the cerebrospinal fluid on the T2 weighted image. tient, who had a right head tilt due to cervical arthritis, ocular tilt predicted by fundus photographs was out of proportion to the 5° tilt actually present. Monocular viewing with either eye through a horizontally placed Maddox rod was nondiagnostic in our case since the subtle cyclorotation of the short vertical line image with this method was not appreciated. A large vertical line (tangent screen wand at 15 feet) was easily noted \,' i } '1.'-;- to be tilted counterclockwise by 5° with either eye. Results of the latter two tests are not affected by head position and are thus valid indicators of ocular torsion. Symmetrical torsion of each globe, skew deviation, and head tilt have been ascribed to processes affecting an otolith or utricular nerve either in a destructive (5) or irritative (6) process. With a destructive process, head tilt toward the side of the ISOLATED ENVIRONMENTAL TILT 33 lesion, torsion of each globe toward the lesion (ocular counter-rolling) and skew deviation (lower eye toward the side of the lesion) are attributed to input from the functioning utricle. The latter triad is referred to as the ocular tilt reflex (7). Brainstem ischemia (specifically lateral medullary infarction) may cause transient cyclorotation as an early symptom (vide supra). In addition, stimulating the interstitial nucleus of Cajal (presumably involving otolith connections) in the monkey has been noted to produce an ocular tilt reaction (8). Interestingly, in our case, an ectatic vertebral artery was identified compressing the left medulla. Although a cause and effect relationship between this structural finding and the patient's visual symptoms and signs cannot be proved, several questions can still be raised. (a) Could compression of the lateral medulla by a dolichoectatic vessel be having an irritative effect on the left otolith connections that resulted in rightward ocular counter-rolling, one component of the ocular tilt reflex? (b) Could this irritative phenomenon be similar to the mechanism proposed to explain the syndrome of hemifacial spasm (9,10) and possibly trigeminal neuralgia (10)? (c) Are there separate neural connections subserving ocular counter-rolling alone (without accompanying skew deviation and head tilt) located in the medulla? Is the initial symptom of cycloro-tation in syndromes with brainstern ischemia secondary to involvement of these pathways? We hope, after collecting more data from similar cases, to be able to answer these questions. REFERENCES 1. Hornsten G. Wallenberg's syndrome. Part I. General symptomatology with special references to visual disturbances and imbalance. Acta Neurol Scand 1974;50:434-46. 2. Hornsten G. Wallenberg's syndrome. Part II, Oculomotor and oculostatic disturbances. Acta Neurol Scand 1974;50: 447-68. 3. Ropper AH. Illusion of tilting of the visual environment. J Clin Neuro-ophthalmoI1983;3:147-51. 4. Trobe JD. Cyclodeviation in acquired vertical strabismus. Arch OphthalmoI1984;102:717-20. 5. Halmagyi GM, Gresty MA, Gibson WPR. Ocular tilt reaction with peripheral vestibular lesion. Ann Neural 1979;6: 80-3. 6. Deecke L, Mergner T, Plester D. Tullio phenomenon with torsion of the eyes and subjective tilt of the visual surround. Ann NY Acad Sci 1981;374:650-5. 7. Rabinovitch H, Sharpe J, Sylvester T. The ocular tilt reaction. Arch OphthalmoI1977;95:1395-8. 8. Westheimer G, Blair SM. The ocular tilt reaction-a brainstem oculomotor routine. Invest Ophthalmol Vis Sci 1975;14: 833-9. 9. Jannetta PJ, Abbasy M, Maroon Je. Ramos FM, Albin MS. Etiology and definitive microsurgical treatment of hemifacial spasm. JNeurosurg 1977;47:321-8. 10. Jannetta PJ. Observations on the etiology of trigeminal neuralgia, hemifacial spasm, acoustic nerve dysfunction and glossopharyngeal neuralgia: Definitive microsurgical treatment and results in 117 patients. Neurochirurgia (Stuttg) 1977;20:145-54. I Clin Neuro-ophthalmol, Vol. 7, No.1, 1987 |
