Jacobson, Gary P.

Objective.: The Dizziness Handicap Inventory (DHI) is a 25-item self-report questionnaire developed to measure the disabling and handicapping impact of dizziness. The present investigation was conducted in an effort to re-assess the factor structure of the DHI. Study Design.: Retrospective study. Setting.: Tertiary care center. Patients.: Subjects were 1,991 patients who were evaluated in the Mayo Clinic-Rochester Vestibular and Balance Laboratory. Main Outcome Measures.: Exploratory factor analysis: an exploratory bifactor analysis (EFA) with bifactor rotation was used to analyze a random sample of 999 patients. Analyses were used to determine the dominance of the general factor (i.e., total score) relative to the group factor (i.e., subscales). Confirmatory factor analysis: a confirmatory bifactor graded response model was fit with appropriate item-to-group relationships that was discovered by our exploratory analyses. To validate the bifactor model that was identified with the exploratory analyses, a bifactor model with three grouping factors (i.e., Physical manifestations, Catastrophic impact of dizziness, and the Emotional impact of dizziness) were fit to a different random sample of 992 patients using the new item-to-group factor specifications. Results.: In the confirmatory analyses, all items had a positive factor loading on the general factor. There were 14 items that loaded on the general factor only. The rest of the items (n = 11) loaded on both the general factor and one of three group factors. Conclusions.: Conclusions of the study revealed several findings: 1) reporting the result as a total score (i.e., a single general factor) is warranted, and, 2) there is statistical support for the existence of three subscales representing: the Physical manifestations, Catastrophic impact, and Emotional impact of dizziness and vertigo.

Objectives The objectives of this study were (a) to investigate the optimal tone burst duration when recording the cervical vestibular evoked myogenic potential (cVEMP) and the ocular vestibular evoked myogenic potential (oVEMP) and (b) to determine whether monopolar recording influences the latency or amplitude of the cVEMP or the oVEMP. Method Fifteen subjects ( M = 27.7 years, SD = 6.73 years) participated in this study. The participants had no prior history of otological or neurological disease. Both oVEMPs and cVEMPs were recorded at a fixed stimulus level for stimulus durations of 2, 5, 10, and 25 ms. For both cVEMP and oVEMP, responses were obtained using a traditional differential recording montage and a monopolar recording montage. Results The cVEMP and the oVEMP had the greatest amplitude in the 2-ms stimulus condition. There was a statistically significant decrease in amplitude for durations greater than 2 ms. Monopolar and bipolar cVEMP and oVEMP latencies and amplitudes were not significantly different. Conclusion As stimulus duration increased beyond 2 ms, the amplitude of the response decreased for both the cVEMP and the oVEMP. There was no significant change in latency with increasing stimulus duration for either response. These results suggested the optimal stimulus duration for both the oVEMP and cVEMP is 2 ms, and there is no apparent advantage of using a bipolar recording technique.

Objectives: Dizziness, vertigo, and unsteadiness are common complaints of patients who present to primary care providers. These patients often are referred to otology for assessment and management. Unfortunately, there are a small number of specialists to manage these patients. However, there are several dizziness disorders that can be successfully managed by primary care providers if the disorder is properly identified. To assist in the identification of several of the most common dizziness disorders, we developed the dizziness symptom profile (DSP). The DSP is a self-report questionnaire designed to generate one or more differential diagnoses that can be combined with the patient’s case history and physical examination. Design: This report describes three investigations. Investigations 1 and 2 (i.e., exploratory and confirmatory investigations, N = 514) describe the development of the DSP. Investigation 3 (N = 195) is a validation study that describes the level of agreement between the DSP completed by the patient, and, the differential diagnosis of the otologist. Results: The final version of the DSP consists of 31 items. Preliminary findings suggest that the DSP is in agreement with the differential diagnoses of ear specialists for Meniere’s disease (100% agreement), vestibular migraine (95% agreement), and benign paroxysmal positional vertigo (82% agreement). Conclusions: Early results suggest that DSP may be useful in the creation of differential diagnoses for dizzy patients that can be evaluated and managed locally. This has the potential to reduce the burden on primary care providers and reduce delays in the diagnosis of common dizziness and vertigo disorders.

ObjectiveThe purpose of this study was to describe the variability and test–retest reliability of a commercially available subjective visual vertical (SVV) system known as Virtual SVV (Interacoustics). In addition, the study aimed to compare the reliability of the Virtual system with a previously established bucket test of SVV.Study DesignFifteen participants with normal hearing, normal middle ear function, and normal utricular function were included in the study. Each participant underwent static SVV testing using both the Virtual system and the bucket test. Subjects completed 2 testing sessions to determine test–retest reliability. For each test, data were collected with the head at 0°, tilted 45° to the right, and tilted 45° to the left.SettingThis study was conducted in a balance function laboratory embedded in a large, tertiary care otology clinic.ResultsThe mean SVV values obtained with the Virtual system were within 1°–2° from 0 with the head positioned at 0°, which is in agreement with many other studies of SVV with the head at 0° (Akin & Murnane, 2009; Halmagyi & Curthoys, 1999; Zwergal, Rettinger, Frenzel, Dieterich, & Strupp, 2009). Using the intraclass correlation coefficient, test–retest reliability of the Virtual system was excellent in the 45° left position and fair to good in the 45° right and 0° position. Test–retest reliability of the bucket test was poor in all head positions.ConclusionsThe Virtual system is a more reliable measure of static SVV than the bucket test. Therefore, the Virtual system could be utilized as a screening device for utricular dysfunction in busy clinical settings.