Wall-Eyed Monocular Internuclear Ophthalmoplegia (WEMINO) and Millard-Gubler Syndromes in a Patient with Isolated Pontine Infarction: Topographic, Oculomotor, and Radiological Analysis of Two Very Uncommon Conditions

Abstract

The syndromes of wall-eyed monocular internuclear ophthalmoplegia and Millard-Gubler are very rare clinical complexes commonly caused by pontine infarction, hemorrhage, or tumors that compromise the paramedian tegmentum, medial longitudinal fascicle, and the basis pontis. We present the case of a 58-year-old female with an isolated pontine infarction characterized by acute vertigo, sudden horizontal diplopia due to ipsilateral internuclear ophthalmoplegia with exotropia, facial palsy and contralateral hemiparesis. This report analyzes, theorizes, and emphasizes the correlation between these atypical neurological findings, the pontine anatomy, and magnetic resonance imaging; encouraging the clinician to make expeditious diagnoses using the bedside skills and a high-quality oculomotor clinical examination. The phenotype and simultaneity of both syndromes makes this case a didactic exercise for the topo-diagnosis based on the neurology of eye movements, the intrinsic physiology of the pons, and the pathways that emerge or project towards it.

Keywords: Exotropia; Internuclear ophthalmoplegia; Millard-Gubler syndrome; Pontine infarction; WEMINO.

Fig. 1

a In the primary position, left hypertropia (skew deviation) and partial exotropia are observed. A mild left lagophthalmos is also evident. b Rightwards, the left eye is limited for a complete adduction. c Leftwards, no deficit is noticed. d, e Vertical misalignment is increased looking upward and downward without limitation or paresis, though.

Fig. 2

a T2-weighted axial MRI slice T2 showing a parasagittal hyperintense image through the pons, encompassing the topography of the facial colliculus, medial lemniscus, and the corticospinal and corticobulbar tracts. b T2-weighted sagittal section showing the floor of the fourth ventricle and a hyperintensity that extends from the facial colliculus (tectum) to the ventral pons. c T2-weighted coronal cut across the central portion of the pons. It shows areas of infarction (hyperintense image) of the left medial pontine component corresponding with the anteromedial pontine artery territory.

Fig. 3

Cross-section diagram of the middle-lower pons. The area shaded in red represents the extension of the patient's infarct. On the opposite side, the labels highlight the involved anatomical structures. Adapted with permission from Marshall Strother (user:mcstrother) and Patrick J. Lynch, medical illustrator (CC BY 3.0 https://creativecommons.org/licenses/by/3.0/; https://commons.wikimedia.org/wiki/File:Lower_pons_horizontal_KB.svg).