Sensory Training for Visual Motion Sickness

This is a preliminary study to determine the reliability and validity of new tests of orientation and balance, as well as to test the effects of a new treatment for visually induced dizziness. Tests involve determining vertical alignment. The treatment is task-based and involves focusing attention on internal body sensations to help improve the sense of upright. Testing is done twice before and twice after treatment, which is provided twice-weekly during a three-week period between testing. The total time participants are involved in the study is approximately six weeks.

Falls are a major concern for people living in countries all over the world. Tens of millions of people who fall are seriously injured and hundreds of thousands of people who fall die every year. People who are dizzy are far more likely to fall. The investigators are particularly interested in working with people who have dizziness that is caused by watching motion or looking at complex patterns (e.g. checkerboard patterns, walking through grocery store aisles, riding in vehicles, or watching movies).

This type of dizziness or vertigo is typically described as motion sickness or, more specifically, visually-induced dizziness. This problem affects adults who are healthy and adults who have a variety of health conditions. No diagnostic tests for this condition exist at this time and the treatments currently being used may result in worsening dizziness for some patients.

New tests were created for orientation and balance, as well as a new treatment for visually-induced dizziness. This is a preliminary study of the reliability and validity of the tests we developed, as well as whether the new treatment created results in reduced dizziness, improved balance, and changes in daily functioning.

It is not known whether the new tests of orientation and balance are better, worse, or the same as existing tests in the ability to detect problems, nor is it known if the new treatment technique is any better, worse, or the same as existing treatments for dizziness and imbalance. It is hypothesized that the new tests will be accurate and able to detect problems in impaired adults. Additionally, that the treatment will result in less dizziness, better balance, and reduced risk of falling.

The plan is to enroll a total of 30 people in this study, 15 who are healthy and 15 who have visually-induced dizziness due to a vestibular (inner ear) problem. Each participant will complete several questionnaires and tests of balance performance before and after undergoing the treatment. Participants attend 8 visits over 6 weeks. Each study visit lasts approximately 60 minutes.

During visits 1 and 2, which is a double baseline phase, the reliability and validity of the new testing procedures will be assessed. All participants will then enter the treatment phase (visits 2 through 7) and will attend twice-weekly appointments for three consecutive weeks. Following the treatment phase, participants will be re-assessed twice, immediately after (visit 7) and one week after (visit 8) completing treatment. During this phase, the short-term effectiveness of the treatment will be assessed.

Participants will complete questionnaires that measure the intensity of visually-induced dizziness, perceived handicap due to dizziness, and the impact of dizziness on daily functioning. Performance measures include the ability to determine what is upright based on the internal sense of gravity (verticality), standing upright, and walking-related balance tasks. The verticality tests are performed while the participant is secured in a harness and are either standing upright or tilted to the left or to the right. The testing task is to determine upright based on using internal body sensations. The standing balance test is performed on a platform that measures balance. The verticality tests and the standing balance test are experimental.

The treatment is task-based and is performed while the participant is supported in a harness and wearing virtual reality goggles. During the treatment, participants are either standing upright or tilted to the left or to the right. The treatment involves focusing attention on internal body sensations to help determine whether an image that is presented in an otherwise black virtual environment is aligned with gravity. Other visual and sound cues will be eliminated to prevent the use of these cues from influencing decisions about what is upright. As the participant becomes more successful at determining what is upright, the difficulty of the treatment task is gradually increased.

Participants symptoms will be monitored throughout the testing and treatment. Participants are given regular rest breaks and may request to rest at any time. Participation is voluntary and may be discontinued at any time.

The investigators anticipate only mild and infrequent side effects related to testing and treatment. The results of this study may influence how orientation and balance are assessed and how visually-induced dizziness is treated.

Eligibility Criteria:
Healthy Participants:

Inclusion Criteria: Participants must

* have normal self-reported cognitive function
* speak English fluently
* weigh less than 225 pounds and be less than 6'4"
* be able to support their body weight in an upright posture for 15 minutes at a time
* be able to follow the guidelines regarding permitted and prohibited additional treatments outlined in this protocol

Exclusion Criteria: Participants must not

* be pregnant or planning to become pregnant while in "on study" status
* have best-corrected visual acuity \> 20/70
* have a self-reported, uncompensated, binocular vision abnormality, such as strabismus, amblyopia, or diplopia
* have peripheral neuropathy
* have a self-reported history of frequent syncope (\>1/month)

Participants with Visually-induced Dizziness:

Inclusion Criteria: Participants must

* have self-reported symptoms of visually-induced dizziness
* have normal self-reported cognitive function
* speak English fluently
* weigh less than 225 pounds and be less than 6'4"
* be able to support their body weight in an upright posture for 15 minutes at a time
* be able to follow the guidelines regarding permitted and prohibited additional treatments outlined in this protocol

Exclusion Criteria: Participants must not

* be participating in vestibular and balance rehabilitation therapy and/or be pregnant or planning to become pregnant while in "on study" status
* have best-corrected visual acuity \> 20/70
* have a self-reported, uncompensated, binocular vision abnormality, such as strabismus, amblyopia, or diplopia
* have peripheral neuropathy, and/or 5) have a self-reported history of frequent syncope (\>1/month)