Unilateral Internuclear Ophthalmoplegia Research Articles

Unilateral Internuclear Ophthalmoplegia in a 14-year-old Female

Purpose: Internuclear ophthalmoplegia (INO) is an eye movement disorder caused by a lesion of the medial longitudinal fasciculus. It typically manifests bilaterally and is commonly caused by multiple sclerosis. We report a case of pediatric unilateral INO, which is rare in the pediatric population.Case summary: A 14-year-old female, with a history of traumatic head injury 9 days previously, presented with diplopia, nausea and vomiting for the past 5 days. Her ophthalmic examination revealed severely impaired adduction of the right eye and abduction nystagmus in the left eye. Orbital computed tomography showed no evidence of orbital wall fracture or muscle impingement. However, an magnetic resonance imaging of her brain demonstrated an infarct in the right paramedian midbrain, leading to a diagnosis of unilateral INO. Diplopia and impaired adduction of the right eye resolved completely 7 weeks after the trauma.Conclusions: Demyelinating diseases, such as multiple sclerosis, account for most of the pediatric INO cases. Although most of these cases are bilateral, this reports highlights a pediatric case of unilateral INO following head injury, which is an uncommon occurrence in this age group.

Unilateral Internuclear Ophthalmoplegia and Upbeat Nystagmus Due to a Rapidly Enlarging Cavernous Malformation and Associated Developmental Venous Anomaly.

Unilateral Internuclear Ophthalmoplegia and Upbeat Nystagmus Due to a Rapidly Enlarging Cavernous Malformation and Associated Developmental Venous Anomaly.

Conservative and Surgical Management of Unilateral and Bilateral Internuclear Ophthalmoplegia (INO)-A Retrospective Analysis.

To report the outcomes of the natural progression and ophthalmic treatment of patients reviewed in a tertiary hospital trust with unilateral or bilateral internuclear ophthalmoplegia. A retrospective case note analysis was performed and 33 patients diagnosed with unilateral or bilateral internuclear ophthalmoplegia (INO) were identified. The diagnosis, aetiology, presence of diplopia, ophthalmic management options and progression were recorded and analysed. This included both conservative and surgical management. The most common aetiologies of INO within this cohort were stroke/ischaemic (69.7%) and multiple sclerosis (MS) (30.3%). Unilateral INO was more prevalent than bilateral INO, with 20 cases (60.6%) compared to 13 cases (39.4%), respectively. A higher proportion of unilateral INO were attributed to stroke (90%) whilst a higher proportion of bilateral INO were attributed to MS (61.5%). The most prescribed management at primary assessment was occlusion (45.5%) and prisms (24.2%). Some patients required no orthoptic intervention (30.3%). Two patients had surgical management of strabismus secondary to bilateral INO. Occlusion was the most common form of management for symptomatic relief of diplopia. Patients who presented at the first visit with no symptoms were unlikely to need any orthoptic intervention. Of the two patients who went on to require surgical intervention, restoration of binocular single vision (BSV) was achieved post-operatively with the use of a Fresnel prism. However, the differences in both surgical technique and number of surgeries required make this difficult to generalise. Additional research is needed to further explore the surgical management of INO.

Case of multiple sclerosis presenting as unilateral internuclear ophthalmoplegia

A 30-year-old female presented with complaints of decreased vision and diplopia since 1 week along with headache and gait disturbances. Examination revealed medial restriction of ocular movements in the right with left abducting nystagmus suggestive of right-sided internuclear ophthalmoplegia and right-sided facial palsy. The patient was admitted under neurology as a suspected case of demyelinating disorder. Magnetic resonance imaging with gadolinium contrast revealed features suggestive of probably multiple sclerosis (MS). The patient was given 5 days of high-dose intravenous steroids following which the patient showed improvement and was discharged on multivitamins. Subsequent follow-up showed significant improvement in symptoms, visual acuity, and ocular movements. Hereby presenting a rare case of MS presenting as unilateral internuclear ophthalmoplegia.

Unilateral Internuclear Ophthalmoplegia Following Minor Head Injury

A lesion in the medial longitudinal fasciculus (MLF) causes internuclear ophthalmoplegia (INO). Many intracranial lesions, such as multiple sclerosis or vascular disorders may be associated with INO; however, INO is a rare complication of minor head injury. The mechanism underlying injury to the MLF may be shear force on the brain stem during head trauma. The shear force can tear or stretch the fibers of the MLF and can also lead to compromise or rupture of the perforating branches of the basilar artery. We present an unusual case of unilateral INO after minor head injury in a patient with a small site of hemorrhage in the midline of the pontomesencephalic junction, confirmed by brain magnetic resonance imaging using susceptibility-weighted imaging.

Atypical presentation of multiple sclerosis – A few points to ponder

The article by Dr. Aishwarya Angadi has brilliantly highlighted how multiple sclerosis can present as unilateral internuclear ophthalmoplegia. The author has meticulously examined the patient and presented it along with the detailed neurological findings. Early detection of multiple sclerosis can go a long way in reducing the morbidity of the disease through timely treatment and intervention. From an academic point of view, there are a few points that I would like to contribute. Since the patient complained of visual blurring, subclinical optic neuritis should have been ruled out with a visually evoked potential test.[1] In the cerebrospinal fluid study, the number of oligoclonal bands is significant for the prognosis of multiple sclerosis.[2] In a case of multiple sclerosis, NeuroMyelitis Optica Immunoglobulin G (NMOIgG) and anti-Myelin Oligodendrocyte Glycoprotein (anti-MOG) antibody should be tested.[345] Lesions on Magnetic Resonance Imaging (MRI) should fulfil McDonald's criteria to qualify as those of multiple sclerosis. MRI orbit is relevant in this case. Also, MRI brainstem should show lesions in the medial longitudinal fasciculus to explain the internuclear ophthalmoplegia. As this patient was positive for Anti Neutrophil Cytoplasmic Antibodies (ANCA), autoimmune vasculitis should also be ruled out. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.

A Case Report of Primary Position Downbeating Nystagmus in Association with a Unilateral Internuclear Ophthalmoplegia (INO) Secondary to a Dorsal Midbrain Infarction. (4937)

A Case Report of Primary Position Downbeating Nystagmus in Association with a Unilateral Internuclear Ophthalmoplegia (INO) Secondary to a Dorsal Midbrain Infarction. (4937)

Author response: Impaired vestibular responses in internuclear ophthalmoplegia: Association and dissociation.

I thank Dr. Johnston for her interest in our article and helpful comments on the mechanisms of impaired vestibulo-ocular reflex (VOR) during head impulses in patients with isolated unilateral internuclear ophthalmoplegia (INO).1

Editors' note: Impaired vestibular responses in internuclear ophthalmoplegia: Association and dissociation

In “Impaired vestibular responses in internuclear ophthalmoplegia: Association and dissociation,” Choi et al. determined that the medial longitudinal fasciculus (MLF) serves as the main passage for the high-acceleration vestibulo-ocular reflex (VOR) from the contralateral posterior canal. They also concluded that the associations and dissociations of the vestibular dysfunction indicate variable combinations of damage to the vestibular fibers ascending or descending in the MLF in strokes causing isolated unilateral internuclear ophthalmoplegia (INO). Dr. Johnston raises concerns regarding these conclusions. Based on her experience, horizontal VOR latencies are normal in patients with INO, implying integrity of direct VOR. She explained that undamaged fibers in MLF or extrafascicular pathways can still initiate the VOR without delay. Dr. Kim, senior author of the study, points out, in Dr. Johnston's study, that the VOR was recorded only in the eye on the lesion side by adopting lower velocity and acceleration of head motion and did not specify the lesion extent or INO as an isolated finding. He also adds that her suggestion does not explain the preservation of the head impulse VOR for the ipsilesional anterior canal in the presence of impairments for other canals, and impaired VOR gains in the eye on the contralesional side in patients with strictly isolated unilateral INO. These findings support separate brainstem pathways for posterior and anterior canal projections pertaining to high acceleration stimuli. In “Impaired vestibular responses in internuclear ophthalmoplegia: Association and dissociation,” Choi et al. determined that the medial longitudinal fasciculus (MLF) serves as the main passage for the high-acceleration vestibulo-ocular reflex (VOR) from the contralateral posterior canal. They also concluded that the associations and dissociations of the vestibular dysfunction indicate variable combinations of damage to the vestibular fibers ascending or descending in the MLF in strokes causing isolated unilateral internuclear ophthalmoplegia (INO).

Unilateral Internuclear Ophthalmoplegia Due to Microvascular Pontine Infarction

Internuclear Ophthalmoplegia (INO) is a clinical syndrome which develops due to a lesion in the medial longitudinal fasciculus (MLF). It is a horizontal gaze disorder characterized by impaired adduction of eye on the side of the lesion of medial longitudinal fasciculus with dissociated nystagmus of the opposite abducting eye. This lesion is mostly caused by multiple sclerosis (usually bilateral lesion), stroke and tumours. A case with unilateral internuclear ophthalmoplegia due to vascular lesion was admitted in Anwer Khan Modern Medical College & Hospital on 27/05/2017.Anwer Khan Modern Medical College Journal Vol. 9, No. 1: Jan 2018, P 71-74

Impaired vestibular responses in internuclear ophthalmoplegia: Association and dissociation.

To determine the role of the medial longitudinal fasciculus (MLF) in conveying vestibular signals. In 10 patients with isolated acute unilateral internuclear ophthalmoplegia (INO) due to an acute stroke, we performed comprehensive vestibular evaluation using video-oculography, head impulse tests with a magnetic search coil technique, bithermal caloric tests, tests for the ocular tilt reaction, and measurements of subjective visual vertical and cervical and ocular vestibular evoked myogenic potentials (VEMPs). The head impulse gain of the vestibulo-ocular reflex (VOR) was decreased invariably for the contralesional posterior canal (PC) (n = 9; 90%) and usually for the ipsilesional horizontal canal (n = 5; 50%). At least one component of contraversive ocular tilt reaction (n = 9) or contraversive tilt of the subjective visual vertical (n = 7) were common along with ipsitorsional nystagmus (n = 5). Cervical or ocular VEMPs were abnormal in 5 patients. The MLF serves as the main passage for the high-acceleration VOR from the contralateral PC. The associations and dissociations of the vestibular dysfunction in our patients indicate variable combinations of damage to the vestibular fibers ascending or descending in the MLF even in strokes causing isolated unilateral INO.

Preferential Impairment of the Contralesional Posterior Semicircular Canal in Internuclear Ophthalmoplegia.

The vertical vestibulo-ocular reflex (VOR) may be impaired in internuclear ophthalmoplegia (INO) as the medial longitudinal fasciculus (MLF) conveys VOR-signals from the vertical semicircular canals. It has been proposed that signals from the contralesional posterior semicircular canal (PSC) are exclusively transmitted through the MLF, while for the contralesional anterior canal other pathways exist. Here, we aimed to characterize dysfunction in individual canals in INO-patients using the video-head-impulse test (vHIT) and to test the hypothesis of dissociated vertical canal impairment in INO. Video-head-impulse testing and magnetic resonance imaging were obtained in 21 consecutive patients with unilateral (n = 16) or bilateral (n = 5) INO and 42 controls. VOR-gains and compensatory catch-up saccades were analyzed and the overall function (normal vs. impaired) of each semicircular canal was rated. In unilateral INO, largest VOR-gain reductions were noted in the contralesional PSC (0.55 ± 0.11 vs. 0.89 ± 0.08, p < 0.001), while in bilateral INO both posterior (0.43 ± 0.11 vs. 0.89 ± 0.08, p < 0.001) and anterior (0.58 ± 0.19 vs. 0.88 ± 0.09, p < 0.001) canals showed marked drops. Small, but significant VOR-gain reductions were also found in the other canals in unilateral and bilateral INO-patients. Impairment of overall canal function was restricted to the contralesional posterior canal in 60% of unilateral INO-patients, while isolated involvement of the posterior canal was rare in bilateral INO-patients (20%). Reviewers correctly identified the INO-pattern in 15/21 (71%) patients and in all controls (sensitivity = 84.2% [95%-CI = 0.59.5-95.8]; specificity = 95.5% [95%-CI = 83.3-99.2]). Using a vHIT based overall rating of canal function, the correct INO-pattern could be identified with high accuracy. The predominant and often selective impairment of the contralesional posterior canal in unilateral INO further supports the role of the MLF in transmitting posterior canal signals. In patients with acute dizziness and abnormal vHIT-results, central pathologies such as INO should be considered as well, especially when the posterior canal is involved.

Vestibulo-ocular reflex deficits with medial longitudinal fasciculus lesions

The medial longitudinal fasciculus (MLF) is the final common pathway for all conjugate adducting horizontal eye movements, as well as for the vertical-torsional vestibulo-ocular reflex (VOR). MLF lesion causes adduction paresis of ipsilesional (adducting) eye with dissociated nystagmus of contralesional (abducting) eye-the well-known clinical syndrome of internuclear ophthalmoplegia (INO). We measured the VOR stimulation and also any catch-up saccades, from individual semicircular canal (SCC) evoked by the head impulse test (HIT), using head and binocular 3-dimensional scleral search coils in 27 multiple sclerosis (MS) patients, 8 with unilateral, 19 with bilateral INO. In unilateral INO, VOR gain (normal >0.90) from ipsilesional lateral SCC stimulation was 0.48 for the adducting eye and 0.81 for the abducting eye; 0.61 from contralesional anterior SCC stimulation and only 0.29 from contralesional posterior SCC stimulation. In bilateral INO, there were VOR gain deficits from all six SCCs: lateral SCC gains were asymmetrically reduced to 0.45 in the adducting eye and 0.66 in the abducting eye; anterior SCC gain was 0.48 and posterior SCC gain was only 0.19. Horizontal VOR versional dysconjugacy between adducting and abducting eyes at 0.66 was less severe than horizontal catch-up saccade versional dysconjugacy (0.44); normal >0.80. Unexpected partial preservation of horizontal VOR with greater catch-up saccade impairment from the adducting than abducting eye suggests that the ascending tract of Deiters(ATD), an extra-MLF pathway, also mediates the horizontal VOR, but not adducting horizontal saccades. Vertical VOR deficits will produce vertical oscillopsia with any vertical head movement and measurement of the vertical VOR could help with the diagnosis and quantitative evaluation of MLF lesions in suspected MS. Horizontal VOR deficits and catch-up saccade versional dysconjugacy in INO will cause gaze instability and horizontal oscillopsia during active horizontal head movements.

Gaze palsy and exotropia in internuclear ophthalmoplegia

Background and purposeUnilateral gaze palsy associated with internuclear ophthalmoplegia (INO), i.e., one-and-a-half syndrome, is well known. Exotropia can also be associated with INO, but it has been reported only rarely. We sought to determine the frequencies and courses of gaze palsy and exotropia in INO. MethodsPatients hospitalized with acute-onset INO during the period January 2009 through December 2013 were identified from our clinical registry. Associated gaze palsy and exotropia were evaluated in the identified patients. ResultsTwenty-five patients with unilateral INO and 7 patients with bilateral INO were included in this study. Of the 25 patients with unilateral INO, 4 (16.0.0%) had ipsilateral gaze palsy (one-and-a-half syndrome), 8 (32.0%) had exotropia (non-paralytic pontine exotropia), and 6 (24.0%) had both ipsilateral gaze palsy and exotropia (paralytic pontine exotropia). Six (85.7%) of the 7 patients with bilateral INO had exotropia. The gaze palsy persisted more than 1week in 40.0% of patients, whereas the exotropia disappeared within 1week in 92.9% of patients when the INO was unilateral. ConclusionExotropia is not uncommon in the acute stage of INO. However, it is often overlooked because of its short duration.

Internuclear Ophthalmoplegia in Pontomesencephalic Stroke as the First Manifestation of Takayasu Arteritis

Takayasu arteritis (TA) is a chronic inflammatory disease affecting the aorta and its main branches. Patients generally present with symptoms such as fever, myalgia, limb claudication, carotid vessel tenderness, hypertension, and asymmetric pulses. Neurological manifestations are present in a small percentage of patients, with stroke occurring in about 10% of cases. Stroke, occurring as the very first presentation of the disease, is however unusual. We present an atypical case of unilateral internuclear ophthalmoplegia (INO) due to acute pontomesencephalic stroke in the absence of cerebral angiographic abnormality, in a 36-year-old woman as the initial presenting feature of TA. The patient had angiographic evidence of bilateral subclavian artery stenosis but no abnormality in the cerebral vessels, thus pointing toward a possible embolic origin from inflamed vessels. Though other unusual neurological manifestations have been reported, INO as the first manifestation has not been found in medical literature so far.

Bedside tested ocular motor disorders in multiple sclerosis patients.

Background/Aims. Ocular motor disorders (OMDs) are a common feature of multiple sclerosis (MS). In clinical practice, if not reported by patients, OMDs are often underdiagnosed and their prevalence is underestimated. Methods. We studied 163 patients (125 women, 76.7%, 38 men, 23.3%; median age 45.0 years; median disease duration 10 years; median EDSS 3.5) with definite MS (n = 150, 92%) or clinically isolated syndrome (n = 13, 8%) who underwent a thorough clinical examination of eye movements. Data on localization of previous relapses, MS subtype, and MRI findings were collected and analyzed. Results. Overall, 111/163 (68.1%) patients showed at least one abnormality of eye movement. Most frequent OMDs were impaired smooth pursuit (42.3%), saccadic dysmetria (41.7%), unilateral internuclear ophthalmoplegia (14.7%), slowing of saccades (14.7%), skew deviation (13.5%), and gaze evoked nystagmus (13.5%). Patients with OMDs had more severe disability (P = 0.0005) and showed more frequently infratentorial MRI lesions (P = 0.004). Localization of previous relapses was not associated with presence of OMDs. Conclusion. OMDs are frequent in patients with stable (no relapses) MS. A precise bedside examination of eye motility can disclose abnormalities that imply the presence of subclinical MS lesions and may have a substantial impact on definition of the diagnosis and on management of MS patients.

Ocular vestibular evoked myogenic potentials to head tap and cervical vestibular evoked myogenic potentials to air-conducted sounds in isolated internuclear ophthalmoplegia

ObjectiveThe central pathways responsible for ocular vestibular evoked myogenic potentials (VEMPs) to forehead tapping remain to be determined. This study aimed to determine whether the medial longitudinal fasciculus (MLF) carries the signals for ocular VEMPs (oVEMPs) in response to this mode of stimulation. MethodsTwelve patients with isolated unilateral internuclear ophthalmoplegia (INO) due to brainstem infarction underwent evaluation of the ocular tilt reaction (ocular torsion and skew deviation), tilt of the subjective visual vertical (SVV), cervical VEMPs (cVEMPs) in response to tone burst sound, and oVEMPs induced by tapping the forehead. ResultsEight (67%) patients showed abnormal oVEMPs that included no wave formation (n=4) and decreased amplitude (n=3) in the lesion side, and bilaterally absent responses in the remaining patient. Furthermore, the patients showed diminished oVEMPs responses in the lesion side compared with normal side (6.0±5.6 vs. 11.7±5.5μV, paired t-test, p=0.001) and increased IADamp(%) of the oVEMPs compared with normal controls (43.6±41.2 vs. 9.1±6.2, t-test, p=0.018). In contrast, cVEMPs were abnormal in only three (25%) patients, decreased (n=2) or no response in the lesion side. Eleven (92%) patients showed contraversive ocular tilt reaction or SVV tilt. ConclusionPatients with INO frequently show impaired formation of ipsilesional oVEMPs in response to forehead tapping. The occasional abnormality and decreased amplitude of ipsilesional cVEMPs also suggest a modulatory pathway for the inhibitory sacculocollic reflex descending in the MLF. SignificanceThis study suggests that the MLF contains the fibers for the otolith-ocular reflex from the contralateral ear.

Internuclear ophthalmoplegia caused by an isolated ischemic lesion affecting the medial longitudinal fascicle

WCN 2013 No: 950 Topic: 3 — Stroke Internuclear ophthalmoplegia caused by an isolated ischemic lesion affecting the medial longitudinal fascicle T. Rab, I. Vastagh, V. Varadi, K. Szőke, G. Bozsik, G. Varallyay, G. Rudas, D. Bereczki. Department of Neurology, Semmelweis University Faculty of Medicine, Hungary; MRA Research Center, Semmelweis University, Budapest, Hungary Background: Internuclear ophthalmoplegia (INO) frequently appears in multiple sclerosis, but is rare as an isolated sign in stroke. Objective: To present clinical and imaging data of 3 cases of ischemic stroke with unior bilateral INO. Patients and methods: Two patients with unilateral and another one with bilateral INOwere investigated by a 3 Tesla Philips Achieva scanner. Results: A 66-year-old female and a 62-year-old male were admitted with acute right sided and an 80-year-old male with bilateral INO. Diffusion weighted MRI scans (DWI) confirmed restricted water diffusion in the medial longitudinal fascicle (MLF) in all cases. Unilateral INO was associated with unilateral MLF lesion whereas in the patient with bilateral signs the MLF was also affected on both sides. Hypertension was present in all three patients. Two patients had hyperlipidemia, one had diabetes, and one was a heavy smoker. The patient with bilateral INO had malignant melanoma which could also have caused prothrombotic state. Antiplatelets (aspirin or clopidogrel) were administered in all patients. The clinical signs were resolved in the patient with bilateral INO after two months. Patients with unilateral INO also improved during the first month after their stroke and their follow-up is ongoing. Conclusion: INO due to a small infarct affecting the MLF may cause unior bilateral signs. As Fisher proved, signs can be bilateral if the terminal branch of a paramedian artery divides and these vessels supply the MLF on both sides. Such small arteries are not visible however even for a 3 Tesla MRI. doi:10.1016/j.jns.2013.07.735 Abstract — WCN 2013 No: 949 Topic: 3 — Stroke Assessment on preadmission treatment of cardioembolic stroke patient in Malaysian hospital WCN 2013 No: 949 Topic: 3 — Stroke Assessment on preadmission treatment of cardioembolic stroke patient in Malaysian hospital N.N. Sidek, Z. Abdul Aziz, I. Looi, P.H. Chee, H. Md. Rafia. Pharmacy Department, Hospital SultanahNur Zahirah, Kuala Terengganu, Malaysia; Neurology Department, Hospital Sultanah Nur Zahirah, Kuala Terengganu, Malaysia; Medical Department, Hospital Seberang Jaya, Seberang Perai, Malaysia; Medical Department, Hospital Kepala Batas, Kepala Batas, Malaysia; Neurology Department, Hospital Kuala Lumpur, Kuala Lumpur, Malaysia Background: Atrial fibrillation (AF) increases the degree of stroke risk up to five times and doubled the overall mortality rate. Hence, anticoagulant as stroke primary prevention is vital. Objectives: We aim to assess the preadmission treatment received by the cardioembolic stroke patients, and review the mortality rate according to pre-treatment received. Method: This prospective study has been carried out from 1st Jan 2010 to 31st December 2012 by 11 Malaysian hospitals. Data have been collected by using Malaysian National Stroke Registry (NSR) case report form which then will be transferred to web application. For analysis, data was extracted and analyzed by using PASW 18. Results: There were 126 cardioembolic stroke patients registered to NSR with mean age of 65.97 ± 12.72 years old. Of all, only 45 patients were on Warfarin with 13 (10.3%) of them were within therapeutic and 32 patients (25.4%) received subtherapeutic Warfarin. 3.2% of patients received dual antiplatelet therapy, 26.2% on single antiplatelet therapy and 34.9% of patient did not received any treatment. The mortality rate was significantly high in no treatment group (34.1%) as compared to Warfarin (13.3%) and antiplatelet group (16.2%) with p value of 0.038. However, the mortality rate between Warfarin therapeutic (7.7%) with sub-therapeutic group (15.6%) and between single antiplatelet (18.7%) with dual antiplatelet were not significantly different. Conclusion: Our findings warrant greater effort to prevent stroke in AF patients, thus high mortality outcome which was significantly associated with treatment received prior to stroke event. doi:10.1016/j.jns.2013.07.736 Abstract — WCN 2013 No: 937 Topic: 3 — Stroke Establishing the aetiology of stroke in a young cohort WCN 2013 No: 937 Topic: 3 — Stroke Establishing the aetiology of stroke in a young cohort R. O'Connor, I. Noone, S. O'Riordan, N. Tubridy, C. Mc Guigan. Department of Neurology, St Vincent's University Hospital,

Ocular tilt reaction, internuclear ophthalmoplegia, and torsional nystagmus following mitral commissurotomy

Ocular tilt reaction, a type of skew deviation, and unilateral internuclear ophthalmoplegia with torsional nystagmus resulting from an ischemic event may result from unilateral disruption of otolithic pathways in the medial longitudinal fasciculus. A subset of skew deviations is known to simulate superior oblique palsy; however, none have been reported with a coexisting internuclear ophthalmoplegia. The present report documents the rare occurrence of an ocular tiltreaction simulating a left superior oblique palsy from involvement of left medial longitudinal fasciculus at the level of interstitial nucleus of Cajal.

Transposition Surgery for Internuclear Ophthalmoplegia

To report outcomes of an extraocular muscle transposition procedure for surgical correction of internuclear ophthalmoplegia. Records of patients operated on between January 1999 and May 2011 were reviewed to identify patients treated with an extraocular muscle transposition procedure for internuclear ophthalmoplegia. Indications for this procedure included a known unilateral or bilateral internuclear ophthalmoplegia with a large-angle exotropia, a moderate adduction limitation, and a large-angle exodeviation in primary position. All patients underwent orthoptic evaluation preoperatively and postoperatively. Examination included assessment of subjective complaints, visual acuity, deviation in diagnostic positions of gaze, and limitation of ocular motility. Five patients were identified. The mean reduction in exodeviation at distance after surgery was 59 ± 25 prism diopters, giving a mean percent reduction in exodeviation of 99.6% ± 0.1%. Four of five patients achieved primary position orthotropia at distance; the remaining patient had 2 prism diopters of exodeviation. One patient who had a residual exodeviation after the initial transposition procedure did not have accompanying ipsilateral lateral rectus recession, but achieved orthotropia with a subsequent ipsilateral lateral rectus recession. Transposition surgery is an effective option for surgical treatment of patients with internuclear ophthalmoplegia with exodeviation and diplopia when combined with ipsilateral lateral rectus recession.