Clinical Application of the Sinusoidal Harmonic Acceleration Test

Abstract

Eighty nine cases of peripheral vestibular lesions were examined by the sinusoidal harmonic acceleration test, SHA, and the results were compared with caloric test abnomalities. The average phase lag of SHA decreased in the rotation to the lowest frequency (0.01 Hz), resulting in a typical “peripheral type” curve. Even the patients with a normal caloric response showed a significant decrease in the phase lag at the lowest frequency. In the rotation to 0.02 Hz, the phase lag tended to decrease according to the degree of the caloric canal paresis. The above findings indicate that SHA is more sensitive in detection of peripheral lesions than the conventional caloric test. Furthermore, SHA to 0.02 Hz appears to be useful for diagnosing more extensive vestibular lesions.