Caloric test findings in a patient with recurrent disequilibrium. (Vestibulology Clinic).

A 38-year-old man first came to the office with a complaint of two episodes of dizziness. The first, which had occurred 2 years earlier, was characterized by a lack of balance while walking or standing. He also reported a lightheaded component to his symptoms. He was prescribed lorazepam, which provided some mild benefit. Findings on magnetic resonance imaging were negative. His dizziness persisted for 6 weeks, then disappeared.

The second episode had occurred 2 weeks prior to his first office visit. The patient had noticed the dizziness upon awakening. Once he was out of bed, he noted a problem with his balance and a feeling of lightheadedness. He was restarted on lorazepam but, again, the benefit was minimal. His symptoms were most intense when he was standing and walking; they were not present when he was lying down, and they were only minor when he was seated and moving his head. Although his dizziness was not severe, it was intrusive and distracting. The patient had no subjective hearing loss, tinnitus, or aural fullness. His family history was positive for hearing loss and tinnitus. He performed the sharpened tandem Romberg's test with difficulty.

The patient went on vacation, and when he returned to the office for testing, he reported that his symptoms had disappeared while he had been away, only to recur to a lesser degree when he returned to work. While under the effects of lorazepam and hydroxyzine HCl (for chronic pruritus), the patient underwent electronystagmography, which revealed no spontaneous or positional nystagmus. Alternate binaural bithermal testing elicited hyperactive responses (>25[degrees]/sec) to the cool stimulus in both ears and to the warm stimulus in the left ear. According to Jongkees' formula, the patient had no reduced vestibular response or directional preponderance (DP). Simultaneous binaural bithermal testing yielded a type 3 response with a left-beating nystagmus. A type 3 response defines DP and is abnormal. Some of these findings, especially the hyperactive responses to caloric stimulation, might have reflected the effects of his drug therapy. Nevertheless, combined with his history, they suggested the presence of a peripheral vestibular disorder.

From Neurotologic Associates, P.C., New York City.