The vestibular system controls the sense of balance and maintains the posture of the body in space. A very simple analogy would be: without the vestibular system intact, one will be unable to do move around without stumbling like a drunkard, let alone hold yoga postures. The vestibular system consists of structures located outside and inside the brain. Specifically, these structures are the inner ear, the vestibulocochlear nerve, vestibular nuclei in brainstem, and the cerebellum. Several other structures in the brain transmit these vestibular signals and allow the brain to perceive vestibular sense. Disruption of any of these structures will result in vestibular disease.
Vestibular disease can be caused by inner ear disease, cerebrovascular disease (stroke), transient ischemic attack (TIA), meningoencephalitis (brain inflammation or infection), structural abnormalities, hypertension, hypothyroidism, hemorrhage, intoxication, side effects from medications, and cancer. Some vestibular disease may be diagnosed as ͞idiopathic vestibular disease͟ when no underlying cause is found.
One of the main challenges is to determine if the vestibular disease is outside the brain (peripheral vestibular disease) or inside the brain (central vestibular disease). Occasionally, the neurologic examination is frustrating at best. This puts important emphasis on advanced imaging either with computed tomography (CT) or magnetic resonance imaging (MRI). A cerebrospinal fluid (CSF) tap may be performed. Finally, the culmination of clinical signs, neurologic examination, imaging results, and CSF analysis are used to reach the diagnosis and a directed treatment plan for the presumptive disease is instituted.