Recovery of Visual Acuity in People With Vestibular Deficits

This study has been completed.
Sponsor:
Collaborator:
Information provided by (Responsible Party):
Susan Herdman, Emory University
ClinicalTrials.gov Identifier:
NCT00411216
First received: December 12, 2006
Last updated: June 24, 2014
Last verified: June 2014
  Purpose

The purpose of this study is to determine whether exercises relieve the symptoms of dizziness and imbalance in people with vestibular deficits and improves the ability to see clearly during head movements. We hypothesize that the performance of specific adaptation and substitution exercises will result in an improvement in visual acuity during head movements while those patients performing placebo exercises will show no improvement.


Condition Intervention
Vestibular Neuronitis
Vestibular Neuronitis, Bilateral
Vestibular Schwannoma
Other: Control exercises
Other: gaze stabilization exercises

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Masking: Single Blind (Subject)
Primary Purpose: Treatment
Official Title: Recovery of Visual Acuity in Vestibular Deficits

Resource links provided by NLM:


Further study details as provided by Emory University:

Primary Outcome Measures:
  • Change in Visual Acuity During Head Movement From Baseline to Discharge [ Time Frame: pre-intervention and at discharge ] [ Designated as safety issue: No ]

    visual acuity is measured using a computerized system first with the head stationary and then with the head moving in yaw plane. Head velocity is measured using a rate sensor and optotype is displayed only when head velocity is between 120 and 180 degrees per second.

    The change in visual acuity was calculated from subtracting the discharge measurement from the baseline measurement (pre-intervention).


  • Subjective Complaints: (All Pre- and Post-intervention): [ Time Frame: pre-intervention, 2 weeks, 4 weeks and at discharge ] [ Designated as safety issue: No ]
    questionnaire


Secondary Outcome Measures:
  • Vestibular Function: Caloric Test (Pre-intervention); Rotary Chair Test (Pre- and Post-intervention) [ Time Frame: caloric test: pre-intervention; rotary chair test pre- and post-intervention ] [ Designated as safety issue: No ]
    bithermal caloric test; step rotations at 60 and 240 degrees per second rotary chair tests

  • Disability Scale [ Time Frame: pre-intervention, 2 weeks, 4 weeks and at discharge ] [ Designated as safety issue: No ]
    questionnaire

  • Activities Specific Balance Confidence Scale [ Time Frame: pre-intervention, 2 weeks, 4 weeks and at discharge ] [ Designated as safety issue: No ]
    questionnaire

  • Symptoms Intensity for Dizziness, Oscillopsia, Disequilibrium [ Time Frame: pre-intervention, 2 weeks, 4 weeks and at discharge ] [ Designated as safety issue: No ]
    visual analoque scales

  • Balance and Gait [ Time Frame: pre-intervention, 2 weeks, 4 weeks and at discharge ] [ Designated as safety issue: Yes ]
    gait speed

  • Fall Risk (Dynamic Gait Index) [ Time Frame: pre-intervention, 2 weeks, 4 weeks and at discharge ] [ Designated as safety issue: Yes ]
    performance test

  • Eye Movements: Scleral Search Coil [ Time Frame: pre- and post-treatment ] [ Designated as safety issue: Yes ]
    eye movements are measured by having the participant sit within an electromagnetic field while wearing a scleral coil (like a contact lens but only in contact with the sclea, not the cornea); te coil moves with eye movement and distorts the electrimagnetic field


Enrollment: 23
Study Start Date: August 2000
Study Completion Date: December 2004
Primary Completion Date: December 2004 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: exercises for gaze stabilization
Experimental group performed vestibular adaptation and substitution exercises
Other: gaze stabilization exercises
adaptation and substitutin exercises encorporating retinal lsip and head movements
Placebo Comparator: Control exercises
Saccadic eye movements against a Ganzfeld to prevent retinal slip error signal; no head movements
Other: Control exercises
saccadic eye movements against a plain background; no head movements

Detailed Description:

Decrements in visual acuity during head movement in patients with vestibular hypofunction are potentially serious problems. This deficit could contribute to decreased activity level, avoidance of driving with resultant diminished independence and, ultimately, limited social interactions and increased isolation. Oscillopsia occurs because of inadequate vestibulo-ocular reflex (VOR) gain and suggests that compensation for the vestibular loss has not occurred. The purpose of this study was to examine the effect of an exercise intervention on visual acuity during head movement in patients with unilateral and bilateral vestibular hypofunction. We hypothesized that 1) patients performing vestibular exercises would have improved visual acuity during head movement compared to patients performing placebo exercises; 2) there would be no correlation between dynamic visual acuity (DVA) and the patients' subjective complaints of oscillopsia; and 3) improvement in DVA would be reflected by changes in residual vestibular function as indicated by an increase in VOR gain.

Patients are assigned randomly to either the vestibular exercise or placebo exercise group. The randomization schedule is generated using a computer program for 2-sample randomization. The sequence was not concealed from the investigator who obtained consent from the subjects and supervised the exercises (SJH). The group assignment (vestibular exercise or placebo exercise) was concealed from the participants and from the investigator who performed the outcome measures.

The vestibular exercise group practiced exercises that consisted of adaptation exercises and eye-head exercises to targets (Table 1), which were designed to improve gaze stability 16. They also performed gait and balance exercises. The placebo exercise group performed exercises designed to be 'vestibular-neutral'.

  Eligibility

Ages Eligible for Study:   18 Years to 80 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

  • Patient had to have either a unilateral vestibular or bilateral vestibular hypofunction defined as follows: Unilateral vestibular deficits were defined by a > 25% difference in slow phase eye velocity between right and left sides on either the caloric or rotary chair test. Bilateral vestibular deficits were defined included refixation saccades made in response to unpredictable head thrusts to the right and left, a gain < .1 on rotary chair step test and a peak slow phase eye movement of <5 degrees/sec during irrigation of each ear on bithermal water caloric testing
  • Healthy subjects with normal vestibular function test results
  • must be able to complete DVA test

Exclusion Criteria:

  • Patients with central lesions will be omitted from the study because vestibular adaptation or other compensatory mechanisms may be compromised and
  • Patients with visual acuity when the head is stationary of 20/60 or worse.
  • Patients on medication that suppress or facilitate vestibular function will not be excluded from the study but data will be analyzed to assess the effect of medication.
  • Patient who do not understand the purpose of the study and what it involves
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT00411216

Locations
United States, Georgia
Center for Rehabilitation Medicine, Emory University
Atlanta, Georgia, United States, 30322
Sponsors and Collaborators
Emory University
Investigators
Principal Investigator: Susan J Herdman, PhD Emory University
  More Information

Publications:
Additional publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
Responsible Party: Susan Herdman, Professor, Emory University
ClinicalTrials.gov Identifier: NCT00411216     History of Changes
Other Study ID Numbers: IRB00000336, R01DC003196
Study First Received: December 12, 2006
Results First Received: December 20, 2013
Last Updated: June 24, 2014
Health Authority: United States: Institutional Review Board

Keywords provided by Emory University:
vestibular rehabilitation
vestibular hypofunction

Additional relevant MeSH terms:
Guillain-Barre Syndrome
Neurilemmoma
Neuroma, Acoustic
Neuritis
Vestibular Neuronitis
Neuroendocrine Tumors
Neuroectodermal Tumors
Neoplasms, Germ Cell and Embryonal
Neoplasms by Histologic Type
Neoplasms
Neuroma
Nerve Sheath Neoplasms
Neoplasms, Nerve Tissue
Cranial Nerve Neoplasms
Peripheral Nervous System Neoplasms
Nervous System Neoplasms
Neoplasms by Site
Vestibulocochlear Nerve Diseases
Retrocochlear Diseases
Ear Diseases
Otorhinolaryngologic Diseases
Otorhinolaryngologic Neoplasms
Cranial Nerve Diseases
Nervous System Diseases
Polyradiculoneuropathy
Autoimmune Diseases of the Nervous System
Demyelinating Diseases
Peripheral Nervous System Diseases
Neuromuscular Diseases
Polyneuropathies

ClinicalTrials.gov processed this record on August 01, 2014