Ocular Movement Examination in Peripheral Vestibular Disorders as a Tool to Improve Diagnosis: A Literature Review

Abstract

Background and Objectives: This study reviews the current literature on ocular movements, specifically focusing on nystagmus associated with peripheral vestibular disorders, to enhance diagnostic accuracy. The evaluation of ocular movements, particularly nystagmus, provides essential insights into the function and dysfunction of the vestibular system, helping clinicians distinguish between peripheral and central causes of vertigo and imbalance. Materials and Methods: A comprehensive search of PubMed was conducted using key terms such as "ocular movements", "nystagmus", "vestibular nystagmus", and "peripheral vestibular disorders". Results: The search yielded 2739 titles, and after a rigorous selection process, 52 articles were reviewed in full. Discussion: The review highlights different classifications and types of nystagmus, including physiological and pathological forms, and their diagnostic relevance in vestibular disorders such as benign paroxysmal positional vertigo (BPPV), vestibular neuritis, and Meniere's disease. Diagnostic techniques like video/electro-oculography are emphasized for their role in assessing vestibular function and identifying abnormalities. The study underscores the importance of detailed ocular examination in the diagnosis of peripheral vestibular disorders and proposes an algorithm to aid this process. Conclusions: While not a systematic review, this study highlights the importance of detailed ocular examination in diagnosing peripheral vestibular disorders and presents an algorithm to facilitate this process. It also emphasizes the need for continued research and advancements in vestibular medicine to further understand ocular movements and their clinical significance, ultimately contributing to improved patient outcomes.

Keywords: nystagmus; ocular movements; peripheral vestibular nystagmus; vestibular disorder.

Figure 1

Flow diagram for the literature review on ocular movements induced by peripheral vestibular disorders as a tool to improve diagnosis.

Figure 2

Video-oculography graph showing a horizontal-torsional nystagmus with the fast phase beating to the left in a patient with acute right peripheral vestibulopathy. The right eye movement is represented by a line colored in red and the left eye in blue. The dots represent the nystagmus secuses. The upper graph is for the horizontal and the lower one is for the vertical movements of the eyes. The torsional movement is decomposed in two directions.

Figure 3

VNG graph. Caloric testing of a patient with acute unilateral vestibulopathy showing right caloric areflexia with left directional preponderance. The different colored dots represent nystagmus obtained following the warm and cold irrigation of each ear. Note that the right ear irrigation does not produce caloric nystagmus. The patient has a constant left beating represented in green unaffected by the caloric stimulation of the right ear.

Figure 4

Rotational sinusoidal pendular test assessing the slow phase velocity of the per-rotational nystagmus compared to the rotary chair velocity. The report includes the measurement of the gain, the phase, and the symmetry. The red eye is represented in red, the left eye is represented in blue. The lines are representations of the eye movements and the dots represent the slow phase velocity.

Figure 5

Algorithm for diagnosing vestibular disorders based on the nystagmus characteristics.