Caloric testing in a patient with disequilibrium and nausea. (Vestibulology clinic).

A 57-year-old man came to the office with a 3-month history of dizziness, which began after he had undergone a colonoscopy. He also began to experience bitemporal and nuchal headaches, which resolved when he removed his eyeglasses or reclined. Each episode of balance disturbance lasted approximately 3 days. Thereafter, he said he felt "off." His symptoms became more intense when he moved his head back and forth. During the 3 days leading up to his visit, his balance problems were accompanied by associated nausea. The patient reported no subjective hearing loss, tinnitus, or aural fullness. His family history was positive for dizziness, diabetes, and heart disease.

A clinical neurotologic examination with a 2,048-Hz tuning fork revealed a reduction in hearing in the right ear. The patient had difficulty performing the sharpened tandem Romberg test (moreso with the right foot forward), and he exhibited bilateral nuchal tenderness. Findings on magnetic resonance imaging (FLAIR algorithm) obtained 2 days prior to the clinical examination were negative.

Electronystagmographic testing detected nystagmus in the left neck torsion position; the nystagmus was less intense but still present in the left lateral position. Alternate binaural bithermal testing evoked a nystagmic response and indicated a significant right-beating directional preponderance (DP), but no significant reduced vestibular response (RVR). Simultaneous binaural bithermal testing revealed a clear RVR on the right.

In this patient, the DP on the alternate binaural bithermal stimulus revealed an abnormality, but it had no localizing value. The simultaneous binaural bithermal, however, did localize the abnormality to the right ear or vestibular nerve. The nystagmus on the warm simultaneous binaural bithermal test evoked the most intense nystagmus of all the caloric stimuli.