Electronystagmography in a patient with a peripheral vestibular disorder.

A 49-year-old woman came to the office with a long history of dizziness. The dizziness began 20 years earlier while she was 6 months pregnant. She said she experienced a lightheaded feeling, difficulty concentrating, difficulty walking, and diaphoresis. Her condition became worse after she delivered her child, and her dizziness persisted for 18 months. Even after the dizziness subsided, she still experienced the lightheaded feeling and had difficulty walking. She said that during the previous 5 years, she had experienced seven spells of vertigo, which were marked by a spinning feeling, nausea, and vomiting. These spells generally lasted for 3 days and were alleviated to some degree by hydroxyzine. Her two most recent spells had occurred just 4 days apart. She said alprazolam had helped somewhat (she had been taking this medication for the previous 13 years).

The woman reported that she had had hearing loss in her left ear since she was 11 years old. In addition, during the previous 10 to 12 months, she had had tinnitus in the same ear. The tinnitus was constant and did not change during her dizzy spells.

Electronystagmography revealed no spontaneous, positional, or neck torsion nystagmus. Her alternate binaural bithermal test showed a 29% reduced vestibular response (RVR) in the left and a 0% directional preponderance. The warm response in the left ear was also reduced. Her simultaneous binaural bithermal test revealed a type 2 response, RVR left, which indicated that the left ear was the source of her dizziness.