Non-Paralytic Pontine Exotropia as a Predominant Sign of Brainstem Infarction - A Case Report

The association of internuclear ophthalmoplegia (INO) with exotropia in the contralateral eye is a rare finding, known as non-paralytic pontine exotropia (NPPE). We report a case of an 80-year-old woman with acute onset of diplopia on admission who presented with left eye exotropia with left-beating nystagmus whilst fixating with the right eye and inability to adduct the right eye on left gaze. Brain magnetic resonance imaging showed two small areas of vertebrobasilar territory ischaemic stroke, one beneath the inferior portion of the aqueduct and another in the right occipital lobe. Our case highlights an interesting clinical manifestation of brainstem infarction that, along with ocular motility examination, allowed us to review its pathophysiology, including the influence of the contralateral paramedian pontine reticular formation stimulation in the mechanism of contralateral exotropia in NPPE. The fast clinical resolution of these cases can explain the scarcity of NPPE reports.

Progressive Supranuclear Palsy with Wall-Eyed Bilateral Internuclear Ophthalmoplegia Syndrome: Authors' Second Case

Wall-eyed bilateral internuclear ophthalmoplegia (WEBINO) syndrome has previously been reported in only 2 patients with progressive supranuclear palsy (PSP). Herein, we report a third case of WEBINO syndrome with PSP. The patient was an 81-year-old man who had experienced gradually increasing gait disturbance and occasional falls since the age of 78 years. At 80 years of age, he presented with cognitive impairment, parkinsonism, and oculomotor abnormalities. The oculomotor abnormalities consisted of vertical gaze palsy and loss of eye convergence. Brain magnetic resonance imaging demonstrated marked atrophy of the midbrain. He was diagnosed with PSP. At the age of 81 years, he presented with alternating extropia in his forward gaze and adduction paresis and outward nystagmus of the abducted eye in his horizontal gaze, both of which were compatible with WEBINO syndrome. Previously, we reported the first case of PSP with WEBINO syndrome, and another group recently reported a second case. In light of the previous cases and the present case, WEBINO syndrome in PSP should not be considered extremely rare. Furthermore, WEBINO syndrome has not been reported in other neurodegenerative disorders, which suggests that it might be a useful and specific diagnostic finding in PSP.

Gaze palsy and exotropia in internuclear ophthalmoplegia

BACKGROUND AND PURPOSE

Unilateral 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.

METHODS

Patients 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.

RESULTS

Twenty-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 1 week in 40.0% of patients, whereas the exotropia disappeared within 1 week in 92.9% of patients when the INO was unilateral.

CONCLUSION

Exotropia is not uncommon in the acute stage of INO. However, it is often overlooked because of its short duration.

[Webino syndrome caused by meningovascular syphilis. A rare entity with an unexpected cause]

CASE REPORT

The patient is a 57-year-old obese and hypertensive male. His chief complaints were double vision and dizziness, with mild exodeviation in both eyes in primary gaze position in the ocular motility examination, but more predominant in the left eye. The exotropia was noticeably more evident on the attempted upgaze. On horizontal gaze, the abducting eye deviated fully, but the adducting eye did not cross the midline. Nystagmus in the abducting eye and convergence impairment were found. Pupil size and testing were normal. Ataxia and areflexia were also present. Bilateral internuclear ophthalmoplegia was suspected and imaging and laboratory tests were performed. The CAT scan showed a right occipital hypo-attenuated lesion. In the MRI scan, a mesencephalic subacute ischemic lesion was found, involving the medial rectus sub-nuclei. Blood and cerebrospinal fluid test for syphilis were positive.

DISCUSSION

Bilateral internuclear ophthalmoplegia is a very uncommon -and difficult to diagnose- condition. In the reported case the lesion involved the medial rectus sub-nuclei. This fact could explain the exotropia in the primary gaze position, and supports that is not possible to exclude the involvement of the medial rectus sub-nuclei in the webino syndrome. The rapid identification of the pathology contributed to the better prognosis of the patient.

Wall-eyed bilateral internuclear ophthalmoplegia in a patient with progressive supranuclear palsy

Wall-eyed bilateral internuclear ophthalmoplegia (WEBINO) is a rare disorder consisting of a bilateral adduction deficit and primary gaze position exotropia. Associated with bilateral medial longitudinal fasciculus lesions, it has been mostly reported in patients with multiple sclerosis and brainstem stroke. A 72-year-old man with characteristic clinical features of progressive supranuclear palsy (PSP) later developed WEBINO. Brain MRI revealed atrophy of the midbrain tegmentum. Caloric irrigation revealed intact horizontal eye movements in both eyes. We believe this to be the first report of WEBINO in PSP. The preservation of vestibulo-ocular horizontal eye movements supports the notion that the WEBINO in this condition was caused by a supranuclear rather than a nuclear lesion and suggests the possibility that even in other causes of WEBINO, the lesion is supranuclear and not in the medial rectus subnucleus as is often suggested.

Wall-Eyed Bilateral Internuclear Ophthalmoplegia From Lesions at Different Levels in the Brainstem

Wall-eyed bilateral internuclear ophthalmoplegia (WEBINO) is a rarely reported syndrome. There is dispute about whether WEBINO is caused by a pontine or a midbrain lesion and whether the medial rectus subnuclei are implicated. In a study of the clinical and imaging features of four patients with WEBINO, we found that that three of four lesions involved the midbrain but not necessarily the medial rectus subnuclei.

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.

Eye deviation in patients with one-and-a-half syndrome

To understand malalignments of the visual axes in one-and-a-half syndrome, we measured eye positions in 4 patients with this syndrome under two conditions: with Frenzel goggles to prevent eye fixation and without Frenzel goggles. When fixation was prevented with the Frenzel goggles, all patients showed mild outward deviation in both eyes. Removal of the Frenzel goggles elicited adduction of the eye ipsilateral to the side of the lesion for fixation, with greater outward deviation of the contralateral eye (acute stage), or adduction of both eyes to midposition for biocular fixation (convalescent stage). In 3 patients whose outward eye deviation with Frenzel goggles was greater on the ipsilateral side, a transition from one-and-a-half syndrome to ipsilateral internuclear ophthalmoplegia was noted, whereas a transition to ipsilateral gaze palsy was seen in the one patient whose deviation was greater on the contralateral side. These findings suggest that in one-and-a-half syndrome patients, the eyes tend to be in divergent positions when fixation is prevented; ipsilateral eye deviation may result from medial longitudinal fasciculus involvement, and contralateral eye deviation may result from paramedian pontine reticular formation involvement. Viewing a target may lead to a secondary deviation or adaptation of eye positions for fixation.

Acquired binocular horizontal diplopia

Binocular horizontal diplopia is an important symptom that may foretell or help localize and characterize various neurologic and neuromuscular disorders. An appropriate evaluation requires a careful and complete neuro-ophthalmic history and examination. This review focuses on the differential diagnosis of binocular horizontal diplopia.