Compensation of Vestibular Function and Plasticity of Vestibular Nucleus after Unilateral Cochleostomy

Figure 3

Sinusoidal harmonic acceleration (SHA) test results after cochleostomy. Before cochleostomy, gain in the SHA test was within the normal range, that is, within two standard deviations of the mean, for all rotation frequencies. However, at 6 hours after cochleostomy, the gain had decreased significantly (a1). After 6, 10, and 20 days, the gain tended to deteriorate with time (b1). Concerning symmetry, the values were within the normal range at all frequencies before cochleostomy; at 6 hours after cochleostomy, the asymmetry significantly deviated toward the side operated on at low frequencies (a2); the deviation recovered slightly after 1 and 3 days but still did not reach the normal range (0.08 Hz) (a2). After 6, 10, and 20 days, the asymmetry recovered and values were within the normal range (b2). White areas indicate normal range, light gray shadow indicates mean ± 1 SD, and dark gray shadow indicates mean ± 2 SD. .