Identification of postural stability and self-perceived handicap in adults with and without chronic unilateral vestibular hypofunction

Significance: Unilateral vestibular hypofunction (UVH) is common amongst adults. In UVH, the initial physiological symptoms typically subside due to central nervous system mechanisms; however, functional challenges can persist and impact patients’ quality of life. Thereby, greater knowledge is needed to identify the functional consequences patients with chronic UVH exhibit to reduce patient fall risk and resolve symptoms. Purpose: This dissertation consists of two specific aims: 1) To identify postural stability differences in patients with/without chronic UVH during dynamic walking tasks and 2) To investigate the relationship between self-perceived handicap scores, postural stability outcomes, and degree of vestibular severity in patients with chronic UVH. Methodology: A total of 50 subjects were recruited (25 with UVH and 25 aged-matched controls). All subjects performed the Dynamic Gait Index (DGI) by walking on an electronic walkway, GaitRITE. Ambulation time (s), cadence (steps/min), step length (cm), stance time (s), and percentage of gait spent in double support (%) were collected via GaitRITE and analyzed for all subjects. Data were compared using a 2 X 6 analysis of variance. To address the second aim, subjects were asked to complete the Dizziness Handicap Inventory (DHI) as a measurement of self-reported handicap. Data were analyzed using non-parametric paired sampled t-test and Spearman’s Rank correlations with Holm alpha-correction. Results: Results indicated significant differences in all gait outcomes between control and UVH subjects for all DGI conditions analyzed (p < 0.05). In addition, significant (p < 0.05) correlations were seen between gait outcomes and DHI scores; however, this was only observed in DGI conditions of walking with horizontal and vertical head turns. A positive correlation was also detected between higher percentage of asymmetry and increased DHI scores in UVH subjects (p < 0.05). Conclusions: Postural stability while ambulating and self-perceived handicap differences do exist in adults with and without UVH. It is apparent that complex tasks of dynamic walking, especially with upper head and trunk movements, are difficult for adults with chronic UVH and may contribute to increased handicap during activities of daily living. Thus, dynamic walking tasks may be utilized by clinicians to aid in their differential diagnosis and decision for secondary referral of dizzy patients.