The Effect of Otolith Dysfunction and Its Rehabilitation in Vestibular Diseases

The Effect and Rehabilitation of Otolith Dysfunction in Vestibular Diseases: A Randomized Comparison of Cawthorne-Cooksey Exercises, 2D Visual Habituation, and 3D/Virtual Reality Visual Habituation

This randomized controlled study compared the clinical and electrophysiological effectiveness of three vestibular rehabilitation approaches in patients with unilateral peripheral vestibular disease accompanied by otolith dysfunction: (1) traditional Cawthorne-Cooksey exercises (CCE), (2) two-dimensional (2D) otolith-targeted visual habituation, and (3) three-dimensional/virtual reality (3D/VR) otolith-targeted visual habituation. Forty-five patients aged 18-60 years were randomized into three groups and followed for 6 weeks. The Dizziness Handicap Inventory (DHI) was used as the primary clinical outcome, and cervical and ocular Vestibular Evoked Myogenic Potentials (cVEMP and oVEMP) were used as objective electrophysiological measures. Patients were monitored remotely using the Moodle learning management system.

Study Overview

• Status: Completed
• Conditions: Rehabilitation; Vestibular Hypofunction; Vestibulopathy; Vestibular Exercises; Vestibular Assessment; Unilateral Vestibular Deficit
• Intervention / Treatment: Behavioral: Cawthorne-Cooksey Exercises; Behavioral: 2D Visual Habituation; Device: 3D/Virtual Reality Visual Habituation

Detailed Description

Vestibular rehabilitation is a cornerstone of management in peripheral vestibular hypofunction. While conventional protocols such as the Cawthorne-Cooksey exercises focus largely on vestibulo-ocular reflex adaptation, otolith organs (utricle and saccule) are often underaddressed despite their critical role in spatial orientation and postural stability. Visual habituation protocols delivering wide-field optokinetic stimuli in the horizontal and vertical planes may target otolith-related symptoms more directly.

In this trial, 45 patients with chronic unilateral peripheral vestibular hypofunction (>3 months post-attack) and VEMP asymmetry >40% were randomized into three groups: CCE (n=16), 2D visual habituation (n=13), and 3D/VR visual habituation (n=16). Each group performed assigned exercises three times daily for 6 weeks, supported by the Moodle e-learning platform. Outcomes were assessed pre- and post-intervention using DHI and cVEMP/oVEMP latency, amplitude, and interaural asymmetry ratio (IAR).

• Study Type: Interventional
• Enrollment (Actual): 45
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Turkey (Türkiye)
  • Istanbul
    • Istanbul, Istanbul, Turkey (Türkiye), 34810
      • İstanbul Medipol University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

Diagnosed unilateral peripheral vestibular disease No identified hearing loss (symmetric hearing) VEMP interaural asymmetry >40% At least 3 months post-acute attack (chronic phase) No ocular disorders No cervical/physical problems No history of psychological or neurological disorders No regular use of alcohol or vestibular suppressant medications Non-fluctuating vestibular symptoms

Exclusion Criteria:

Additional balance disorder pathology beyond unilateral peripheral vestibular disease BPPV repositioning maneuver within the last 30 days Asymmetric or moderate-to-severe hearing loss Motion sickness Active BPPV symptoms in history

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Cawthorne-Cooksey Exercises (CCE); Traditional vestibular rehabilitation protocol consisting of progressive eye, head, and body movements (saccade and VOR exercises, balance exercises) performed three times daily for 6 weeks, with hierarchical difficulty progression across weeks 1-2, 3-4, and 5-6.	Behavioral: Cawthorne-Cooksey Exercises; A classical vestibular rehabilitation protocol promoting central vestibular compensation through habituation and adaptation mechanisms. The 6-week protocol consists of hierarchical eye, head, and body movements progressing across three phases: Weeks 1-2 in sitting position (saccade and VOR exercises, single-leg standing, head shaking with eyes closed); Weeks 3-4 in standing position (saccades and VOR while standing, walking on mat, sit-to-stand exercises); Weeks 5-6 dynamic phase (saccades and VOR while walking, walking with head shaking, single-leg standing on soft surface). Exercises were performed three times daily (morning, noon, evening). Progression was individualized based on symptom provocation. Patients received initial in-clinic training and were followed remotely via the Moodle e-learning platform with weekly video-based exercise modules.
Experimental: 2D Visual Habituation; Otolith-targeted visual habituation using 2D wide-field optokinetic flow videos in horizontal and vertical planes. Patients viewed videos on a screen positioned at eye level at 1 meter distance, three times daily (morning/noon/evening), approximately 15-20 minutes per session, for 6 weeks.	Behavioral: 2D Visual Habituation; A digital visual habituation protocol targeting otolith organs through wide-field 2D optokinetic visual flow stimuli. Pre-recorded videos generating horizontal-plane and vertical-plane motion perception (vection) were used to promote otolith re-weighting and habituation. Participants viewed videos seated in front of a screen at eye level, 1 meter away. Each session lasted 15-20 minutes and was performed three times daily (morning, noon, evening) for 6 weeks. Both horizontal and vertical optokinetic stimuli were delivered per session. Stimulus duration, speed, and complexity were gradually increased according to individual symptom tolerance. Sessions were paused if marked nausea or severe dizziness developed. Patients accessed videos through dedicated Moodle e-learning platform modules via smartphone or computer, ensuring standardized delivery and adherence monitoring.
Experimental: 3D/Virtual Reality Visual Habituation; Otolith-targeted visual habituation delivered via VR headset (VR Shinecon G04ea) presenting 3D wide-field optokinetic flow in horizontal and vertical planes. Same dosing as 2D arm: three times daily, 15-20 minutes per session, for 6 weeks.	Device: 3D/Virtual Reality Visual Habituation; An immersive virtual reality (VR) visual habituation protocol targeting otolith organs through 3D wide-field optokinetic stimuli. The horizontal- and vertical-plane motion stimuli used in the 2D protocol were adapted for VR delivery using Movavi Video Editor 360 software and presented via a head-mounted display (VR Shinecon G04ea, Scinecon, China). Participants were immersed in 3D visual flow scenarios generating motion perception (vection), providing a more naturalistic stimulus than screen-based delivery. Sessions lasted 15-20 minutes and were performed three times daily for 6 weeks. Stimulus intensity and complexity were progressively increased according to tolerance. Short breaks were provided to minimize cybersickness. The Moodle platform supported protocol delivery and remote adherence monitoring. The protocol targeted otolith-related symptoms through systematic desensitization and sensory re-weighting.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Mean change in Dizziness Handicap Inventory (DHI) total score	The Dizziness Handicap Inventory (DHI) is a 25-item self-report questionnaire measuring perceived dizziness-related handicap. Each item is scored as "Yes" (4 points), "Sometimes" (2 points), or "No" (0 points). The total score is calculated by summing all 25 items and ranges from 0 to 100, where 0 indicates no perceived handicap and 100 indicates maximum perceived handicap. Higher scores represent greater dizziness-related disability. The outcome is reported as the mean change in total DHI score, calculated as post-intervention total score minus baseline total score for each participant.	Baseline and 6 weeks post-intervention
Mean change in cervical Vestibular Evoked Myogenic Potential (cVEMP) P13 wave latency	Cervical Vestibular Evoked Myogenic Potential (cVEMP) P13 wave latency is an objective electrophysiological measure of saccular and inferior vestibular nerve function. Recordings were obtained using the Interacoustics Eclipse platform with 500 Hz tone-burst stimuli at 100 dB SPL delivered monaurally through insert earphones. Surface EMG electrodes were placed over the sternocleidomastoid muscle, with the ground electrode at the vertex and reference electrode at the sternum. The latency of the first positive peak (P13) was measured from stimulus onset to peak in milliseconds. The outcome is reported as the mean change in P13 latency, calculated as post-intervention latency minus baseline latency for each participant.	Baseline and 6 weeks post-intervention
Mean change in cervical Vestibular Evoked Myogenic Potential (cVEMP) N23 wave latency	Cervical Vestibular Evoked Myogenic Potential (cVEMP) N23 wave latency is an objective electrophysiological measure of saccular and inferior vestibular nerve function. Recordings were obtained using the Interacoustics Eclipse platform with 500 Hz tone-burst stimuli at 100 dB SPL delivered monaurally through insert earphones. Surface EMG electrodes were placed over the sternocleidomastoid muscle. The latency of the negative peak (N23) following the P13 peak was measured from stimulus onset to peak in milliseconds. The outcome is reported as the mean change in N23 latency, calculated as post-intervention latency minus baseline latency for each participant.	Baseline and 6 weeks post-intervention
Mean change in ocular Vestibular Evoked Myogenic Potential (oVEMP) N10 wave latency	Ocular Vestibular Evoked Myogenic Potential (oVEMP) N10 wave latency is an objective electrophysiological measure of utricular and superior vestibular nerve function. Recordings were obtained using the Interacoustics Eclipse platform with monaural acoustic stimuli delivered through insert earphones. Surface electrodes were placed below the contralateral eye over the inferior oblique muscle, with reference electrodes 2 cm below the active electrodes and ground at the vertex. Participants maintained an upward gaze at a fixed visual target during recording. The latency of the first negative peak (N10) was measured from stimulus onset to peak in milliseconds. The outcome is reported as the mean change in N10 latency, calculated as post-intervention latency minus baseline latency for each participant.	Baseline and 6 weeks post-intervention
Mean change in ocular Vestibular Evoked Myogenic Potential (oVEMP) P15 wave latency	Ocular Vestibular Evoked Myogenic Potential (oVEMP) P15 wave latency is an objective electrophysiological measure of utricular and superior vestibular nerve function. Recordings were obtained using the Interacoustics Eclipse platform with monaural acoustic stimuli delivered through insert earphones. Surface electrodes were placed over the inferior oblique muscle below the contralateral eye, with participants maintaining an upward gaze at a fixed visual target. The latency of the positive peak (P15) following the N10 peak was measured from stimulus onset to peak in milliseconds. The outcome is reported as the mean change in P15 latency, calculated as post-intervention latency minus baseline latency for each participant.	Baseline and 6 weeks post-intervention

Secondary Outcome Measures

Outcome Measure	Time Frame
Change in cVEMP peak-to-peak amplitude from baseline to 6 weeks	Baseline and 6 weeks post-intervention
Change in oVEMP peak-to-peak amplitude from baseline to 6 weeks	Baseline and 6 weeks post-intervention
Change in cVEMP interaural asymmetry ratio (IAR) from baseline to 6 weeks	Baseline and 6 weeks post-intervention
Change in oVEMP interaural asymmetry ratio (IAR) from baseline to 6 weeks	Baseline and 6 weeks post-intervention

Collaborators and Investigators

• Sponsor: Medipol University
• Collaborators: Istanbul Medeniyet University

Publications and helpful links

General Publications

• Smolka W, Smolka K, Markowski J, Pilch J, Piotrowska-Seweryn A, Zwierzchowska A. The efficacy of vestibular rehabilitation in patients with chronic unilateral vestibular dysfunction. Int J Occup Med Environ Health. 2020 Apr 30;33(3):273-282. doi: 10.13075/ijomeh.1896.01330. Epub 2020 Mar 26.
• Chen PY, Hsieh WL, Wei SH, Kao CL. Interactive wiimote gaze stabilization exercise training system for patients with vestibular hypofunction. J Neuroeng Rehabil. 2012 Oct 9;9:77. doi: 10.1186/1743-0003-9-77.
• Lacour M, Helmchen C, Vidal PP. Vestibular compensation: the neuro-otologist's best friend. J Neurol. 2016 Apr;263 Suppl 1:S54-64. doi: 10.1007/s00415-015-7903-4. Epub 2016 Apr 15.
• Dutia MB. Mechanisms of vestibular compensation: recent advances. Curr Opin Otolaryngol Head Neck Surg. 2010 Oct;18(5):420-4. doi: 10.1097/MOO.0b013e32833de71f.
• Fujimoto C, Suzuki S, Kinoshita M, Egami N, Sugasawa K, Iwasaki S. Clinical features of otolith organ-specific vestibular dysfunction. Clin Neurophysiol. 2018 Jan;129(1):238-245. doi: 10.1016/j.clinph.2017.11.006. Epub 2017 Nov 21.
• Baloh RW, Kerber KA. Clinical Neurophysiology of the Vestibular System. p.480, 4th ed. Oxford: Oxford University Press, 2010
• Van De Graaff KM. Senses of hearing and balance. p.516-30. In: Human Anatomy. 6th ed. The McGraw-Hill Companies Publishing, 2001
• Dickman JD. The vestibular system. p.320-333 In: Fundamental Neuroscience for Basic and Clinical Applications. 5th ed. Elsevier Inc, 2018.
• Öndağ N. Periferik vestibüler sistem hastalıklarında uyarılmış vestibüler myojenik potansiyeller (VEMP). Gazi Üniversitesi, 2008.
• Öztürk ŞT. The Effect and Rehabilitation of Otolith Dysfunction in Vestibular Diseases [doctoral thesis]. Istanbul: Istanbul Medipol University; 2026.

Study record dates

Study Major Dates

• Study Start (Actual): March 1, 2025
• Primary Completion (Actual): December 24, 2025
• Study Completion (Actual): March 24, 2026

Study Registration Dates

• First Submitted: November 14, 2025
• First Submitted That Met QC Criteria: May 18, 2026
• First Posted (Actual): May 26, 2026

Study Record Updates

• Last Update Posted (Actual): May 26, 2026
• Last Update Submitted That Met QC Criteria: May 18, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: Virtual reality; Vestibular rehabilitation; VEMP; Dizziness Handicap Inventory; cVEMP; Otolith dysfunction; Visual habituation; oVEMP; Cawthorne-Cooksey exercises
• Other Study ID Numbers: stozturk1; 1063 (21.12.2023) (Other Identifier: Istanbul Medipol University No)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No