ENG in a patient with Meniere's syndrome and evidence of vestibular recruitment.

A 27-year-old woman came to the office with a 3-month history of tinnitus in the left ear. She described it as a constant buzzing sound that fluctuated in loudness and became worse when she talked on the telephone. She thought that the tinnitus might have been present prior to a dizzy spell that she had experienced 4 months earlier. That spell of rotary vertigo had occurred on awakening and had lasted 3 hours. The dizziness was accompanied by nausea, vomiting, and diaphoresis.

Two weeks prior to her office visit, she had experienced a similar spell, which began at 11 p.m. and lasted until 3:30 a.m. During the spell, her tinnitus became louder, and later that day she felt weak. Since then, when she walked along the streets, she found it necessary to concentrate on her walking. She reported no hearing loss or aural fullness.

The only notable finding on clinical examination was difficulty performing the sharpened tandem Romberg's test with the left foot forward. Findings on magnetic resonance imaging were negative, and auditory brainstem-evoked potentials were normal.

The patient did not return to the office for 4 months. When she did, she reported that she had experienced three or four additional dizzy spells; the tinnitus became louder with each successive spell. Electronystagmography revealed a hyperactive cool response in the left ear and a warm-water response that was lower in the left ear than it was in the right. No significant reduced vestibular response or directional preponderance was noted. The simultaneous binaural bithermal test showed a type 3 left-beating nystagmus.

Audiometry revealed that the patient had a moderate, almost flat, sensorineural hearing loss in the left ear and mild low- and high-tone decline in the right ear. Speech testing in the left ear showed a threshold appropriate for the pure tones, with well-preserved speech discrimination. The right ear had an appropriate threshold for the pure tones, but some impairment in speech discrimination was evident (52% at 50 dB and 72% at 60 dB). Tympanometry findings were normal in both ears, and the acoustic stapedial reflex thresholds were cochlear in sensation level in the left ear and normal in the right ear. There was no reflex decay.

The patient's response to the alternate stimulus in the left car was inconsistent, which is not unusual early in Meniere's syndrome. In such cases, the cool response indicates a form of vestibular recruitment and the warm response is low. In Meniere's syndrome, the warm water caloric response in the affected ear is frequently (but not always) the first affected. The type 3 response to the simultaneous binaural bithermal test indicated that this patient had a vestibular system abnormality, although the results had no localizing value. This response could possibly indicate bilateral disease in view of the audiometric results in the asymptomatic right ear.