Ocular Tilt Reaction Research Articles

Otolith dysfunction in vestibular neuritis

To prospectively follow patients with vestibular neuritis (VN), to compare the recovery pattern of canal and otolith dysfunction, and to determine which tests best predict symptom recovery. Between March 2006 and December 2006, 51 consecutive patients with unilateral VN were enrolled within 7 days of onset (average 3 days). Otolith function tests included ocular torsion (OT), subjective visual vertical (SVV), and vestibular evoked myogenic potential (VEMP), and canal function tests included head-shaking nystagmus (HSN), caloric stimulation, and head-thrust testing. Patients returned for two follow-up evaluations at approximately 1 week and 6 weeks after the initial evaluation. On the first examination, all patients had abnormal HSN, caloric, and head-thrust test results, and at least one otolith-related test abnormality: abnormal tilt of SVV (48/51, 94%), abnormal OT (42/51, 82%), or abnormal VEMPs (25/51, 49%). The degree of SVV tilts correlated with the degree of OT for one or both eyes (p < 0.05). Skew deviation was observed in 7 patients (14%), and a complete ocular tilt reaction was detected in only 2 patients. On follow-up, otolith test results returned to normal more rapidly than canal test results. The head-thrust test was the best predictor of symptom recovery. Eighty percent of patients who continued to report dizziness at the last follow-up visit had a positive head-thrust test result, whereas only 10% of patients who were not dizzy had a positive head-thrust test result. Otolith-related test abnormalities improve more rapidly than canal-related test abnormalities after vestibular neuritis. If patients have a positive head-thrust test result on follow-up, they are more likely to be dizzy.

Are signs of ocular tilt reaction in patients with cerebellar lesions mediated by the dentate nucleus?

A sensitive clinical sign of a vestibular tone imbalance in the roll plane is the ocular tilt reaction (OTR), a combination of skew deviation, ocular torsion and head and perceptual tilts such as tilts of the subjective visual vertical (SVV). Of these OTR components tilts of SVV are the most frequent. While these signs are regularly seen in patients with unilateral brainstem lesions, only a few case studies are available on their occurrence in patients with cerebellar lesions. Thus, the question arises whether cerebellar structures may be involved in contra- and/or ipsiversive tilts of the perceived vertical and other signs of OTR. We used lesion-mapping techniques in a total of 31 patients with acute cerebellar strokes, all showing at least a significant tilt of SVV. Twenty-three patients had a contraversive tilt of the SVV; they were compared with eight patients with ipsiversive tilts. MRI/CT lesion mapping revealed that in patients showing contraversive signs of OTR in general and contraversive SVV tilts in particular the dentate nucleus was the commonly damaged structure. In contrast, in ipsiversive signs of OTR, the dentate nucleus was spared and lesions were located in the biventer lobule, the middle cerebellar peduncle, the tonsil and the inferior semilunar lobule. These data suggest that the dentate nucleus is a critical anatomical structure within the cerebellum, belonging to a network involved in vestibular processing such as the perception of verticality. Therefore, a lesion of the dentate nucleus can lead to tilts of the SVV in the contraversive direction, i.e. a vestibular tone imbalance to the contralateral side, whereas cerebellar lesions excluding the dentate nucleus can induce a tone imbalance to the ipsilesional side.

3.7. Are signs of ocular tilt reaction in cerebellar lesions mediated by the dentate nucleus?

3.7. Are signs of ocular tilt reaction in cerebellar lesions mediated by the dentate nucleus?

Ocular tilt reaction

Entsprechend der räumlichen Anordnung der Bogengänge im Innenohr sowie der zentralen Verschaltung des vestibulo-okulären Reflexes (VOR) in 3 verschiedenen Raumebenen werden zentral vestibuläre Syndrome nach Brandt klinisch folgendermaßen eingeteilt: Störungen des VOR in der Horizontalebene führen zu horizontalem Nystagmus und horizontaler Blickdeviation, Störungen des VOR in der Vertikalebene zu vertikalem Nystagmus und vertikaler Blickdeviation, und Störungen des VOR in der Rollebene zu rotierendem Nystagmus und einer Ocular tilt reaction (OTR). Einen deutschen Ausdruck für diese Störung gibt es nicht. Die OTR, als klinisches Zeichen einer zentral-vestibulären Tonusdifferenz in der Roll-Ebene setzt sich aus folgenden vier Komponenten zusammen: Kopfneigung, Abweichung der subjektiven visuellen Vertikalen als sensitivstes Zeichen, Skew deviation (pränukleäre vertikale Schielstellung) und Zykloduktion (gleichsinnige Bulbusverrollung). Die OTR stellt ein häufiges Symptom bei Hirnstammläsionen dar und ist in der Regel mit weiteren zentralen Okulomotorikstörungen kombiniert.

Central Compensation of Central Vestibular Lesions

Background: Peripheral and central vestibular lesions cause a vestibular tone imbalance, that is centrally compensated. Whereas the central compensation of peripheral vestibular lesions has been studied in detail, little is known about central compensation of central lesions. The subjective visual vertical (SVV) – as a component of the ocular tilt reaction – is a useful psychophysical parameter to measure central compensation for two reasons: first, it deviates in most acute peripheral and central vestibular lesions and, second, it normalizes over time despite persisting vestibular deficits. Objective: To determine the time course and degree of central compensation of central vestibular lesions by measuring the deviation of the SVV and to compare these values with those of peripheral lesions in a retrospective study. Methods: 50 patients with Wallenberg's syndrome (as a model for a central vestibular lesion) and 39 patients with vestibular neuritis (as a model for an isolated peripheral vestibular lesion) were examined. SVV was determined during at least two points of time within the first month after symptom onset. Results: The mean displacement of SVV was 10.6° in Wallenberg's syndrome and 10.5° in vestibular neuritis within the first days after onset of symptoms. SVV deviation within the last days of the observation period was averaged at 4° in the former and 3.1° in the latter group. Wilcoxon's rank sum test for matched pairs revealed a significant decrease of the deviation over time in both groups. Although the regression had an exponential character in both groups, the statistical power of individually fitted regression curves (ANOVA) was too low to perform a statistical comparison. Conclusions: We demonstrated that central compensation of a central vestibular lesion has a degree and time course similar to that of a peripheral vestibular lesion. These data provide the basis for a prospective study, which will determine the SVV and ocular torsion over a period of three months.

Upbeat Nystagmus: Clinicoanatomical Correlations in 15 Patients

Background and PurposeThe mechanism of upbeat nystagmus is unknown and clinicoanatomical correlative studies in series of patients with upbeat nystagmus are limited.MethodsFifteen patients with upbeat nystagmus received full neuro-ophthalmological evaluation by the senior author. Nystagmus was observed using video Frenzel goggles and recorded with video-oculography. Brain lesions were documented with MRI.ResultsLesions responsible for nystagmus were found throughout the brainstem, mainly in the paramedian area: in the medulla (n=8), pons (n=3), pons and midbrain with or without cerebellar lesions (n=3), and midbrain and thalamus (n=1). Underlying diseases comprised cerebral infarction (n=10), multiple sclerosis (n=2), cerebral hemorrhage (n=1), Wernicke encephalopathy (n=1), and hydrocephalus (n=1). Upbeat nystagmus was mostly transient and showed occasional evolution during the acute phase. In one patient with a bilateral medial medullary infarction, the upbeat nystagmus changed into a hemiseesaw pattern with near complete resolution of the unilateral lesion. Gaze and positional changes usually affected both the intensity and direction of the nystagmus. A patient with a cervicomedullary lesion showed a reversal of upbeat into downbeat nystagmus by straight-head hanging and leftward head turning while in the supine position. Gaze-evoked nystagmus (n=7), ocular tilt reaction (n=7), and internuclear ophthalmoplegia (n=4) were also commonly associated with upbeat nystagmus.ConclusionsIn view of the responsible lesions and associated neuro-ophthalmological findings, upbeat nystagmus may be ascribed to damage to the pathways mediating the upward vestibulo-ocular reflex or the neural integrators involved in vertical gaze holding.

Medial medullary infarction: Abnormal ocular motor findings

In 20 consecutive patients with isolated medial medullary infarction, abnormal ocular motor findings included nystagmus (n = 8), ocular contrapulsion (n = 5), and contralesional ocular tilt reaction (n = 2). The nystagmus was ipsilesional (n = 4), gaze-evoked (n = 5), upbeating (n = 4), and hemiseesaw (n = 1). The ocular motor abnormalities may be explained by involvements of the nucleus prepositus hypoglossi, medial longitudinal fasciculus or efferent fibers from the vestibular nuclei, climbing fibers, and cells of the paramedian tracts.

Medial Vestibular Nucleus Lesions in Wallenberg's Syndrome Cause Decreased Activity of the Contralateral Vestibular Cortex

Three patients with the clinical diagnosis of Wallenberg's syndrome caused by acute unilateral ischemic infarctions, which included the vestibular nucleus in the medullary brain stem and afferent vestibular pathways, were examined by positron emission tomography (PET) during caloric vestibular stimulation. They all had typical signs of vestibular dysfunction such as transient rotatory vertigo with vomiting at the onset, ipsiversive body and ocular lateropulsion, and a complete ocular tilt reaction with tilts of the subjective visual vertical. Compared with healthy volunteers, who show activation in a network of temporoparietal vestibular areas within both hemispheres, especially in the posterior insula and retroinsular region that contains the human homologue of the parietoinsular vestibular cortex (PIVC) in monkeys, the activation pattern of the patients with Wallenberg's syndrome was typically changed. During caloric irrigation of the ear ipsilateral to the side of the lesion, they showed no or significantly reduced activation in the contralateral hemisphere, whereas the activation pattern in the ipsilateral hemisphere appeared "normal." These results are compatible with bilateral ascending vestibular pathways from the vestibular nuclei to the vestibular cortex. The novel finding in all three patients was that the activation patterns were compatible with the assumption that only the crossing fibers from the medial vestibular subnucleus to the contralateral medial longitudinal fascicle were affected, but the ipsilateral vestibular thalamocortical projections via the superior vestibular subnucleus were spared. Thus, the activation pattern in the PET study may reflect the vestibular tonic imbalance within the vestibular nuclei circuitry at the cortical level.

Wall-Eyed Monocular Internuclear Ophthalmoplegia (WEMINO) with Contraversive Ocular Tilt Reaction

Wall-eyed monocular internuclear ophthalmoplegia (WEMINO) with contraversive ocular tilt reaction has not been previously reported. A 71-year-old woman suddenly developed blurred vision. Examination revealed left internuclear ophthalmoplegia, left exotropia, right hypotropia, and rightward head tilt. Magnetic resonance imaging showed a tiny infarction at the area of the left medial longitudinal fasciculus in the upper pons. WEMINO with contraversive ocular tilt reaction may be caused by a paramedian pontine tegmental infarction that selectively involves the medial longitudinal fasciculus.

General vestibular testing

A dysfunction of the vestibular system is commonly characterized by a combination of phenomena involving perceptual, ocular motor, postural, and autonomic manifestations: vertigo/dizziness, nystagmus, ataxia, and nausea. These 4 manifestations correlate with different aspects of vestibular function and emanate from different sites within the central nervous system. The diagnosis of vestibular syndromes always requires interdisciplinary thinking. A detailed history allows early differentiation into 9 categories that serve as a practical guide for differential diagnosis: (1) dizziness and lightheadedness; (2) single or recurrent attacks of vertigo; (3) sustained vertigo; (4) positional/positioning vertigo; (5) oscillopsia; (6) vertigo associated with auditory dysfunction; (7) vertigo associated with brainstem or cerebellar symptoms; (8) vertigo associated with headache; and (9) dizziness or to-and-fro vertigo with postural imbalance. A careful and systematic neuro-ophthalmological and neuro-otological examination is also mandatory, especially to differentiate between central and peripheral vestibular disorders. Important signs are nystagmus, ocular tilt reaction, other central or peripheral ocular motor dysfunctions, or a unilateral or bilateral peripheral vestibular deficit. This deficit can be easily detected by the head-impulse test, the most relevant bedside test for the vestibulo-ocular reflex. Laboratory examinations are used to measure eye movements, to test semicircular canal, otolith, and spatial perceptional function and to determine postural control. It must, however, be kept in mind that all signs and ocular motor and vestibular findings have to be interpreted within the context of the patient's history and a complete neurological examination.

Posterior canal-type ocular tilt reaction caused by unilateral rostral midbrain hemorrhage

A 56-year-old man receiving treatment for hypertension experienced sudden-onset dizziness and was admitted to our hospital. Computed tomography of the brain revealed a small high-density lesion in the right rostral midbrain. Subsequent magnetic resonance imaging revealed a small hemorrhagic lesion in the same position. The patient complained of double vision affecting the right side when viewing a horizontal linear target. Vergence was intact, but vertical gaze was severely restricted downward and moderately restricted upward. Vestibulo-ocular reflex maneuvers did not alleviate the patient's vertical gaze palsy. By 40 days after the incident, his motility had recovered and he could begin to tilt his head to the left. Consecutive Hess tests demonstrated a skew deviation of right hypertropia, which continued for over two years. Funduscopic examination revealed left extorsion but no right intorsion. A diagnosis of posterior canal-type ocular tilt reaction (OTR) was made from these signs. The patient's course indicated that periaqueductal syndrome dominated in the acute stage whilst unilateral symptoms became more apparent in the chronic stage. The rostral interstitial nucleus of the medial longitudinal fasciculus and the posterior commissure were estimated to contain the main causative lesion for the acute symptoms, whereas the interstitial nucleus of Cajal (INC) was implicated in the chronic stage. Posterior canal-type OTR caused by unilateral INC lesion has been reported only rarely.

Ocular tilt reaction due to a mesencephalic lesion in juvenile polyarteritis nodosa

Purpose To describe a case of ocular tilt reaction caused by vasculitic lesions in the midbrain in a child with polyarteritis nodosa. Design Observational case report. Methods A 5-year-old girl with a chronic illness developed diplopia associated with a left head tilt, right hypertropia, torsional nystagmus, slowed vertical saccades and poor convergence. Fundoscopic examination demonstrated conjugate leftward torsion of the eyes consistent with a sustained ocular tilt reaction. Results Renal angiography confirmed polyarteritis nodosa and cerebral magnetic resonance imaging demonstrated mesencephalic pathology. Conclusions Polyarteritis nodosa is a difficult condition to diagnose in a child and can cause brainstem lesions. This rare case of ocular tilt reaction of midbrain origin highlights that a sustained head tilt in a child can be due to brainstem pathology, rather than a fourth nerve palsy.

The Ocular Tilt Reaction

A patient with ocular motility findings consistent with a right superior oblique palsy was found to have binocular ocular torsion and a head tilt that led to the diagnosis of an ocular tilt reaction. Magnetic resonance imaging disclosed a right pontine lesion presumably involving the descending tract from the interstitial nucleus of Cajal to the contralateral vestibular nucleus. This lesion is located more inferiorly than one would expect in a superior oblique palsy. Physicians should be aware that patients with a vertical deviation and a head tilt might have an ocular tilt reaction, as opposed to a superior oblique palsy.

Neurological evaluation of acute vertical diplopia

Acute vertical diplopia requires an immediate neurological evaluation. The preliminary differential diagnosis is based on a few basic questions, which can be answered by simple clinical tests. The neurologist determines whether the lesion affects the optic, ocular motor, or vestibular system, and confirms that the problem is neural. Otherwise the patient is referred to the ophthalmologist. A thorough neurological assessment then allows concluding whether the lesion is within the central nervous system or peripheral. Photographs of the ocular fundus on both sides help to distinguish between trochlear nerve palsy and ocular tilt reaction or skew torsion. For a finer differential diagnosis, focused MR-imaging is always needed. The diagnosis of an optic disorder should be considered if the vertical diplopia is clearly monocular. If vertical diplopia is binocular, the neurologist first searches for typical oculomotor (III) or trochlear nerve (IV) palsies. While III-palsy is mostly due to ischaemia (pupil typically spared) or compression (pupil typically affected) of the nerve, IV-palsy is mostly due to head trauma. III- and IV-palsies that go together with retroorbital pain should lead to a careful evaluation for neoplasm, thrombosis, and inflammation of the cavernous sinus. One can never be absolutely sure whether a typical III- or IV-palsy is due to a problem along the nerve or within the brainstem, except if other signs clearly indicate a lesion within the ipsilateral orbit or cavernous sinus. Thus neuro-imaging should always include MR-imaging of the midbrain to detect lesions in the nuclei and fascicles of the oculomotor and trochlear nerves. If a suspected III-palsy does not include all of the four corresponding extraocular muscles (superior, inferior, and medial recti; inferior oblique), one should also consider myasthenia gravis, which can mimic any neural extra-ocular muscle palsy. Wernicke's disease is always a valid differential diagnosis of binocular vertical diplopia, especially in the presence of pathological nystagmus and ataxia. If binocular vertical diplopia is associated with deficits of multiple cranial nerves, one should consider a demyelinating disease such as Miller-Fisher and Guillain-Barre syndrome. Skew deviation is a vertical misalignment of the two eyes resulting from disturbance of supranuclear inputs to the ocular motor neurons of the vertical-torsional eye muscles. If skew deviation goes together with ocular torsion towards the lower eye, so-called skew torsion, an imbalance in the vestibular system, mainly a unilateral lesion of pathways, which combine otolith and vertical semicircular canal signals, is likely. Skew torsion combined with head roll towards the lower eye forms the triad of ocular tilt reaction (OTR). Consistent with the anatomy of the graviceptive pathways, ipsiversive skew torsion (ipsilateral eye lower, and ipsilateral binocular torsion) and ipsilateral OTR (ipsiversive skew torsion, and ipsilateral head tilt) will occur as a result of unilateral peripheral or pontomedullary lesions below the pontine crossing of the graviceptive pathways. In contrast, a unilateral pontomesencephalic brainstem lesion leads to contraversive skew deviation (contralateral eye lower) and contralateral OTR (contraversive skew deviation, contralateral binocular torsion, and contralateral head tilt).

Skew deviation and inferior oblique palsy

PURPOSE: To describe ocular motility and neuro-ophthalmologic findings in six patients with an ocular tilt reaction (OTR) that mimicked an inferior oblique palsy (IOP). DESIGN: Observational Case Series. METHODS: Series of six patients presenting to tertiary care pediatric or neuro-ophthalmologist. RESULTS: Five patients had ocular motility and three-step test results suggesting an IOP; one patient had a suspected bilateral IOP. All six patients had excyclotorsion of the hypotropic eye, and four had incyclotorsion of the hypertropic eye. This is contrary to that expected with an IOP (incyclotorsion of the hypotropic eye). In addition, all six patients had other neurologic findings in the history or examination that were associated with neurologic insult rather than an isolated IOP. Two patients had surgery consisting of a superior rectus recession; this was successful in eliminating diplopia in both patients and in eliminating the vertical deviation and head posturing in one patient. CONCLUSION: While many vertical deviations that appear to be due to an inferior oblique palsy based on the results of the three-step test may be caused by inferior oblique weakness, skew deviation should also be considered in any patient with a history of head trauma, or other neurologic findings. The cyclotorsion observed in IOP is opposite that seen with OTR, and differentiates the two entities clinically. We postulate that these deviations are caused by damage to the otolithic projections that correspond to those from the ipsilateral posterior semicircular canal (on the side of the hypotropic eye).

Perceived vertical and lateropulsion: clinical syndromes, localization, and prognosis.

We present a clinical classification of central vestibular syndromes according to the three major planes of action of the vestibulo-ocular reflex: yaw, roll, and pitch. The plane-specific syndromes are determined by ocular motor, postural, and perceptual signs. Yaw plane signs are horizontal nystagmus, past pointing, rotational and lateral body falls, deviation of perceived straight-ahead to the left or right. Roll plane signs are torsional nystagmus, skew deviation, ocular torsion, tilts of head, body, and perceived vertical in a clockwise or counterclockwise direction. Pitch plane signs are upbeat/downbeat nystagmus, forward/backward tilts and falls, deviations of the perceived horizon. The thus defined vestibular syndromes allow a precise topographic analysis of brainstem lesions according to their level and side. Special emphasis is placed on the vestibular roll plane syndromes of ocular tilt reaction, lateropulsion in Wallenberg's syndrome, thalamic and cortical astasia and their association with roll plane tilt of perceived vertical. Recovery is based on a functionally significant central compensation of a vestibular tone imbalance, the mechanism of which is largely unknown. Physical therapy may facilitate this central compensation, but this has not yet been proven in prospective studies.

Ocular tilt reaction due to unilateral cerebellar lesion

We report two patients with an ocular tilt reaction (OTR) due to unilateral caudal cerebellar lesion. One patient had a caudal cerebellar hemorrhage, the other a posterior inferior cerebellar artery territory infarct. There was head tilt in both patients which had not been reported previously. These findings support the previous proposal that the mechanism of a tonic contraversive OTR with unilateral cerebellar lesion is an increased tonic resting activity in the ipsilesional vestibular nucleus due to a loss of inhibition from the lesioned nodulus.

Ocular Tilt Reaction with Vertical Eye Movement Palsy Caused by Localized Unilateral Midbrain Lesion

A 60-year-old man developed diplopia and experienced difficulty moving his eyes. Vertical movement of each eye, including vestibulo-ocular reflex and smooth pursuit, was extremely limited. Horizontal eye movements were normal. His head position was tilted toward his left. There was 10 prism diopters of exotropia and 10 prism diopters of right hypertropia. Fundus photographs revealed a clockwise torsion of both eyes. These signs indicate leftward ocular tilt reaction. Magnetic resonance imaging showed a small area of an increased signal intensity localized in the midbrain dorsomedial to the red nucleus on the right side. Based on recent experimental evidence, it may be assumed that the unilateral lesion involving the right interstitial nucleus of Cajal most probably caused leftward ocular tilt reaction in our patient.

Two types of ocular tilt reaction: the ‘ascending’ pontomedullary VOR-OTR and the ‘descending’ mesencephalic integrator-OTR

Ocular tilt reaction (OTR) is a fundamental pattern of eye-head coordination in roll and is elicited by unilateral lesions on the peripheral and central vestibular ‘graviceptive’ pathways from the otoliths and the vertical semicircular canals to the rostral midbrain integration center. We propose the following differentiation between two types of OTR: (1) the ‘ascending’ pontomedullary VOR-OTR with ipsilateral lesions of the vestibulo-ocular reflex pathways in roll, from the labyrinth to the vestibular nuclei. This type is characterized by disconjugate ocular torsion and occurs if anterior, posterior, or both semicircular canal and otolithic pathways are affected and (2) the ‘descending’ mesencephalic integrator-OTR with contralateral lesions of the rostral midbrain integration center (INC) for eye-head coordination in the roll plane. This type is characterized by conjugate ocular torsion. The ‘ascending, reflexive’ type (lateral medulla) of OTR simply reflects a tone imbalance of the VOR, whereas the ‘descending integration’ type (rostral midbrain tegmentum) integrates signals of eye-head velocity with those of holding position and involves cortical control of OTR during active locomotion. The frequent (pontomesencephalic) ‘skew torsion’ without head tilt results from contralateral lesions of crossing ascending ‘graviceptive’ pathways rostral to the downward branching of vestibulospinal connections. It does not cause head tilt, because vestibulospinal tracts are not involved at this site of the lesion.

Herpes zoster neuritis involving superior and inferior parts of the vestibular nerve causes ocular tilt reaction

A 43-year-old woman presented with peripheral facial nerve palsy, rotational vertigo, and hearing loss due to herpes zoster neuritis of the right seventh and eighth cranial nerves. Neuro-ophthalmologic examination showed a horizontal rotatory spontaneous nystagmus (fast phase) to the left and an ocular tilt reaction (OTR) to the right, a pattern of head tilt, skew deviation, ocular torsion, and tilt of perceived vertical. Ocular torsion was binocular but asymmetric with a predominant intorsion of the contralateral hypertropic eye (17° vs 7°). Since a complete OTR is rare in peripheral, but common in central vestibular disorders, involvement of the vestibular nucleus (due to a zoster meningoencephalitis) was first assumed. However, MRI scan (T1-weighted 2D-FLASH sequence) revealed contrast enhancement in both parts (pars superior and inferior) of the right vestibular nerve due to viral inflammation. The following conclusions can be drawn from the correlation of the neuro-ophthalmologic syndrome and MRI findings: (1) the horizontal component of spontaneous nystagmus is secondary to a horizontal semicircular canal paresis; (2) the rotatory component of the spontaneous nystagmus and the tonic OTR are secondary to a combined paresis of the anterior canal, the posterior canal, and the otoliths; and (3) the asymmetry of ocular torsion indicates incomplete loss of vestibular function with predominant involvement of the anterior semicircular canal.