Diazepam tolerance effects on vestibular function testing, part II: vestibulo-ocular reflex parameters during rotational testing.
Author(s): Blau PA, Schwade N, Roland P
Affiliation(s): Dept of Otorhinolaryngology, University of Texas Southwestern Medical Center at Dallas, TX 75390-8876, USA.
Publication date & source: 2005-09, Ann Otol Rhinol Laryngol., 114(9):722-9.
Publication type: Clinical Trial; Randomized Controlled Trial
OBJECTIVES: The purpose of this prospective study was to determine whether clinical doses of diazepam (DZ; 10 mg/d) administered for 14 days result in tolerance as measured by the sinuosidal harmonic acceleration (SHA) rotational test. It has been shown that repeated dosing with DZ leads to accumulation and tolerance in outcome measures that assess memory, sedation, and psychomotor tasks. METHODS: In a double-blinded, repeated-measures design, 30 normal male subjects who ranged in age from 20 to 36 years were randomly assigned to a placebo group or a DZ group and participated in 6 SHA rotational sessions over a 2-week period. Analysis of drug-placebo differences in percent change from baseline was performed with a 1-way analysis of variance. RESULTS: Vestibulo-ocular reflex gain and phase frequencies at 0.01, 0.02, 0.04, and 0.08 Hz were significant (p < .05) for treatment group. No significant effect was observed for gain and phase frequency at 0.16 Hz--a finding that indicates selective effects on different central nervous system mechanisms. There was no statistical significance for time. CONCLUSIONS: Clinically, the DZ subjects' scores remained within the normal ranges for vestibulo-ocular phase and gain, suggesting that patients in whom drug cessation is problematic may not have to discontinue DZ before testing with the SHA rotational system.