Vestibular findings in a patient with a 1-month history of disequilibrium.

A 67-year-old woman presented with a 1-month history of disequilibrium. While walking, she would suddenly become "unbalanced" for up to 2 minutes. These episodes would occur spontaneously at least once a day. They would also occur when she moved from a sitting to a standing position. Her imbalance felt more intense when other people were moving around her. The first spell was more severe than subsequent spells. The patient reported no personal or family history of hearing loss or tinnitus. She did not complain of aural fullness, and there was no history of dizziness in her family.

On clinical examination, the patient exhibited tenderness over the left nuchal area, and she had difficulty performing the sharpened Romberg's test. Her audiology results were normal.

Electronystagmography (ENG) elicited no spontaneous or positional nystagmus; there was ocular fixation suppression of calorically induced nystagmus. Results of the alternate binaural bithermal (ABB) test were normal with respect to individual caloric responses, reduced vestibular response, and directional preponderance. The simultaneous binaural bithermal (SBB) test did not induce any nystagmus that was consistent with equal input into the brainstem. This finding, coupled with the results of the ABB test, represented a normal test result.

ENG had failed to identify any vestibular abnormality in this patient. Based on his experience, the author had expected to see an abnormal response to the SBB test, but did not. Considering that the duration of the patient's symptoms had been so brief, it is possible that a vestibular abnormality had not yet evolved to the point that it was detectable by ENG. It is also possible that the factor that triggered each episode reverted to normal when symptoms abated.

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