Testing of vestibular function: an adjunct in the assessment of chronic fatigue syndrome.

Patients with chronic fatigue syndrome (CFS) often complain of dysequilibrium that is nonspecific. The basis of this complaint is unknown but may be related to vestibular system abnormalities, in that an association between inner-ear deficits and infectious mononucleosis has been established in the medical literature. An overview of quantitative vestibular function testing is given, including vestibulo-ocular and vestibulospinal tests. The basic principles of caloric and rotational testing are provided, including the interaction between vision and the vestibular system. Moving-platform posturography is described. Preliminary results from quantitative vestibular function testing of a small group of individuals with CFS are provided.