Visual vertigo: Vertigo of oculomotor origin

Area of Science:

• Neuroscience
• Ophthalmology
• Vestibular System

Background:

• The traditional view attributes vertigo solely to vestibular dysfunction, following Róbert Bárány's hypothesis on the vestibulo-ocular reflex (VOR).
• Contradictory findings and cases of vertigo with absent inner ear structures challenge the exclusive vestibular origin of vertigo.
• Visually induced vertigo is common, often presenting with only mild inner ear abnormalities, suggesting a significant visual-vestibular interaction.

Purpose of the Study:

• To review the mechanisms of accurate binocular viewing and its role in maintaining balance.
• To explore the influence of the oculomotor system and external ocular muscle (EOM) proprioception on vertigo.
• To propose an alternative approach to understanding vertigo mechanisms beyond the vestibular system.

Main Methods:

• Review of literature on the oculomotor system, binocular vision, and proprioception.
• Analysis of the relationship between visual information processing and balance control.
• Examination of the role of EOM proprioception in motor efferents and whole-body responses.

Main Results:

• Accurate binocular viewing relies on a complex oculomotor system and EOM proprioception.
• EOM proprioception appears to influence the body's motor efferents, impacting balance.
• Oculomotor system errors, including EOM fatigue, can trigger vertigo symptoms.

Conclusions:

• Vertigo may arise from oculomotor system dysfunction, not exclusively vestibular issues.
• The proprioceptive senses of EOMs play a crucial role in maintaining balance and can contribute to vertigo.
• Understanding oculomotor influences offers a new perspective on the mechanisms of vertigo, particularly in visually induced cases.