Diplopia from skew deviation in unilateral peripheral vestibular lesions

Area of Science:

• Neuroscience
• Ophthalmology
• Vestibular System Research

Background:

• Vertical diplopia due to skew deviation is typically associated with brainstem lesions.
• Peripheral vestibular lesions can also manifest with skew deviation, often overlooked.
• The Ocular Tilt Reaction (OTR) encompasses head tilt, eye cyclotorsion, skew deviation, and altered vertical perception.

Purpose of the Study:

• To investigate the occurrence and characteristics of skew deviation in patients with acute unilateral peripheral vestibular deficits.
• To analyze the temporal evolution of skew deviation and associated Ocular Tilt Reaction (OTR) components.
• To clarify the role of peripheral vestibular lesions in causing skew deviation.

Main Methods:

• Clinical evaluation of patients with acute unilateral peripheral vestibular loss (surgical or idiopathic).
• Measurement of skew deviation using the Hess-Weiss test.
• Assessment of static visual vertical using vertical frame and Maddox rod techniques.
• Ocular fundus photography to quantify cyclotorsion.

Main Results:

• Skew deviation with ipsilateral hypotropia and conjugated cyclotorsion was observed in patients with acute unilateral peripheral vestibular loss.
• Tilt of the static visual vertical was noted on the side of the affected ear.
• Skew deviation resolved within days, while cyclotorsion and visual vertical tilt persisted for weeks to months.

Conclusions:

• Skew deviation is a significant component of the Ocular Tilt Reaction (OTR) in acute peripheral vestibular lesions.
• Both surgical and non-surgical peripheral vestibular deficits can trigger OTR manifestations, including skew deviation.
• Understanding OTR in peripheral vestibular disorders is crucial for accurate diagnosis and management of associated visual disturbances.