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Neuro-Ophthalmological Findings in Patients with Posterior Circulation Stroke
Published in Vivek Lal, A Clinical Approach to Neuro-Ophthalmic Disorders, 2023
Skew deviation is characterized by vertical misalignment of the two eyes not caused by paralysis of a single muscle or nerve. The oblique relationship is maintained through all fields of gaze. When the tegmental lesion is in the caudal pons, the ipsilateral eye usually lies below the contralateral eye, while in the rostral pons and midbrain, the ipsilateral eye usually rests above the contralateral eye. Some patients with lesions in the rostral pons involving the paramedian tegmentum in a region near the MLF have had an ipsilateral paresis of abduction accompanied at times by nystagmus of the adducting contralateral eye. Patients with lesions in the pons may have ptosis, often more severe than expected with a Horner's syndrome. The explanation for the ptosis is uncertain but it may relate to the accompanying hemiparesis or facial weakness.17
Vertigo
Published in Philip B. Gorelick, Fernando D. Testai, Graeme J. Hankey, Joanna M. Wardlaw, Hankey's Clinical Neurology, 2020
Christopher C. Glisson, Jorge C. Kattah
Patients with vestibular neuritis present with acute vertigo associated with nausea, vomiting, and motion intolerance. They may also manifest truncal imbalance, with a tendency to fall in the ipsilesional direction. The h-HIS is positive; skew deviation should be regarded as rare. The clinician must ensure that a detailed neurologic examination is complete to rule out pseudoneuritis, as manifested by signs of brainstem or cerebellar stroke, which could be a risk for further neurologic deterioration.
The natural history of brainstem ocular motility disorders due to vascular pathology
Published in Jan-Tjeerd de Faber, 28th European Strabismological Association Meeting, 2020
Skew deviation is an acquired vertical misalignment of the visual axes caused by a disturbance of supranuclear function. (Brandt & Dieterich 1993, Keane 1975). The deviation is more common in unilateral lesions than bilateral lesions and the eye ipsilateral to the lesion is usually the hypotropic eye. Diplopia is often present but no particular extraocular muscle is involved. A comitant skew deviation was noted in one patient in this series. Nystagmus was noted in three patients and included upbeat, downbeat and gaze evoked waveforms. Gaze evoked nystagmus was more prevalent and can be seen during and following recovery of gaze palsies but also with damage to the neural integrators of horizontal and vertical gaze.
Evaluation and Management of Symptomatic Vertical Strabismus and Diplopia
Published in Journal of Binocular Vision and Ocular Motility, 2022
Joseph W. Fong, Laurie A. Hahn-Parrott, R. Michael Siatkowski
Vertical misalignment of the visual axes following damage to the supranuclear control areas for ocular movement is termed the Magendie-Hertwig syndrome or skew deviation.11 In skew deviation, damage may occur anywhere along the utriculo-ocular pathway, from the inner ear to the brainstem. The hypertropic eye is usually incyclotorted, but other patterns of skew deviation may occur depending on exactly where the lesion is.12 Of these, a skew deviation that mimics ipsilateral inferior rectus paresis is most common.13 Strabismus due to skew deviation may or may not get noticeably larger in contralateral gaze or ipsilateral head tilt and generally has incyclotorsion of the hypertropic eye. In comparison, a fourth nerve palsy should get noticeably larger in contralateral gaze and ipsilateral head tilt (unless there has been a spread of comitance) and generally produces excyclotorsion of the hypertropic eye. Skew deviation, however, can produce a comitant vertical strabismus with variable amounts of torsion.
Skew Deviation
Published in Journal of Binocular Vision and Ocular Motility, 2022
Skew deviation is a vertical ocular misalignment caused by disruption of vestibular input to the interstitial nucleus of Cajal (INC), involving the brainstem, the cerebellum and/or the thalamus. First described clinically, its variety of presentations and array of accompanying signs and symptoms made it difficult to characterize with certainty, and this, coupled with a lack of pathophysiologic knowledge, relegated it to a diagnosis of exclusion.1,2 In the past 20 years, work to define the function and pathway of the vestibular system1,3,4 has allowed us to clearly identify skew, use its presence or absence in specific settings to aid differentiation of central versus peripheral disruptions of the vestibular system5 and to predict the location of lesions when other signs are present. Ongoing research works to define the role of the vestibular sensory organs in higher order perception involving cognition and input from more than one sensory modality.6
Measuring acquired ocular torsion with optical coherence tomography
Published in Clinical and Experimental Optometry, 2021
Christopher J Borgman, Jessica A Haynes
Skew deviation is a vertical ocular deviation caused by a supranuclear lesion of the pre‐motor input centres of the posterior fossa.2,4,6 Skew deviation can mimic a trochlear nerve palsy on the Parks‐Bielchowsky three‐step test.2 The key differentiating feature of skew deviations is incyclotorsion of the hyperdeviated eye, compared to excyclotorsion of the hyperdeviated eye in trochlear nerve palsies.2-4,6 Excyclotorsion of the hypodeviated eye can also accompany the incyclotorsion of the hyperdeviated eye in skew deviation.2,4,6 Skew deviations are typically more worrisome than isolated trochlear nerve palsies, as skew deviation strongly suggests a posterior fossa lesion (that is, stroke, demyelination, or tumour) that requires neuroimaging.2,4,6 Therefore, measuring the direction of acquired ocular torsion of the hyperdeviated eye (that is, incyclotorsion versus excyclotorsion) is very important in vertical deviations so as to accurately diagnose or rule out skew deviations.2,6 Another useful consideration for differentiating skew and trochlear nerve palsies is the upright‐supine test, where > 50 per cent improvement of the vertical deviation in the supine position strongly suggests skew deviation rather than trochlear nerve palsy.2,6