Head impulse test abnormalities and influence on gait speed and falls in older individuals.

Objective: To assess the prevalence of vestibular dysfunction in older adults using the head impulse test (HIT) and to assess the independent influence of HIT abnormalities on gait speed and fall risk in older individuals.
Study Design: Cross-sectional study.
Setting: Tertiary care academic medical center.
Patients: Fifty community-dwelling individuals age 70 and older.
Interventions: HIT (abnormal HIT defined as right or left HIT abnormality), visual acuity, monofilament testing, and grip strength.
Main Outcome Measures: Gait speed on a 4-meter walk and a history of falls (including number of falls) in the last 1 and 5 years.
Results: The participants' mean age was 77 years (range, 70-95 yr); 52% were female subjects. Fifty percent of participants had an abnormal HIT. An abnormal HIT was significantly associated with a 0.23 m/s reduction in gait speed (p = 0.042), 0.44 more falls in the last 1 year (p = 0.047), and a 5-fold increase in the odds of falling in the last 5 years (p = 0.024) in multivariate analyses adjusted for age, sex, and other balance and fall risk factors.
Conclusion: We observed that half of the community-dwelling older individuals in our study had evidence of vestibular dysfunction, which was significantly associated with gait speed and fall risk in adjusted analyses. Screening for vestibular impairment using the simple HIT and directing targeted vestibular therapy may be important to reduce gait impairment and fall risk in older individuals.