• Activation of target sites on the functional MRI images during the vestibular response [ Time Frame: Not specific ] [ Designated as safety issue: No ]
  

• Differences in the fiber tracking of central nervous system specifically involved in the vestibular response [ Time Frame: Not specific ] [ Designated as safety issue: No ]
  

The incidence of vertigo has been reported to be as high as 1.5% in the general population and some reports suggest that more than 5% of adults experience some kind of vertigo each year. In 80% of affected individuals, this symptom resulted in a medical consultation, interruption of daily activities, or sick leave. Therefore, vertigo can have a significant impact on health and well being. Unfortunately, there is not yet any satisfactory objective method for diagnosis of vertigo. At present, the diagnosis usually depends on medical history, vestibular function tests, Dix-Hallpike positioning tests done in the office, and, to some extent imaging studies doen to look for such abnormalities such as acoustic tumor, brain tumor, and evidence of multiple sclerosis. A number of recent studies support the possibility of using functional MRI (fMRI), particularly a new diffusion tensor fiber tracking (DTT) technique, as a new tool for diagnosis of disorders that can cause vertigo. In this study, our hypothesis is that there is an alteration in the activity in neural pathways of patients with vertigo that can be detected by fMRI. To test this assumption, our objective in this study is to determine whether there is a difference between the fMRI images obtained in normal subjects versus those in patients with vertigo.