Vestibular Evoked Myogenic Potential (VEMP) Test-Retest Reliability in Children

Objective—Vestibular evoked myogenic potentials (VEMPs) are short-latency muscle potentials measured from the neck (cervical VEMP; cVEMP) or under the eyes (ocular VEMP; oVEMP), which provide information regarding function of the saccule and utricle, respectively. VEMPs are reliable when performed in adults; however, reliability of VEMPs in children is unknown. Therefore, the purpose of the study was to determine the test-retest reliability of c- and oVEMP testing in normal control children. Study Design—Prospective. Setting—Hospital. Patients—Ten adults, 14 adolescent children and 13 young children with normal hearing. Interventions—c- and oVEMP testing were completed across two test sessions in response to air-conduction 500 Hz tone-burst and impulse hammer stimuli. Additionally, oVEMP was completed using eyes-open and eyes-closed conditions. Main Outcome Measures—Intraclass correlation coefficients were calculated to determine the reliability of c- and oVEMP outcomes. Results—When using air-conduction stimuli, c- and oVEMP amplitudes are reliable across test sessions in normal control children and adults. With impulse hammer stimuli, cVEMP amplitudes showed high reliability; however, oVEMP amplitudes showed low reliability in both eyes-open and eyes-closed conditions. Comparison between eyes-open and eyes-closed oVEMP conditions revealed shorter latencies and higher peak-to-peak amplitudes in the eyes-open condition. Conclusions—In this small cohort of normal control children, cVEMPs are reliable using air-conduction and impulse hammer stimuli and oVEMPs are reliable using air-conduction stimuli in the eyes-open condition. oVEMP in eyes-closed conditions were less reliable compared to eyes-open conditions and resulted in a large number of absent responses

Unilateral centrifugation: Effects of age, translation method and vestibular disease on ocular torsion and SVV

Background. Unilateral centrifugation testing is an assessment of unilateral utricular function in which the rotary chair is laterally translated so the axis of rotation is through one utricle. Outcome parameters are the Subjective Visual Vertical (SVV) and ocular torsion. Purpose. The purpose of the study was to examine: (a) how two different methods of lateral translation affect SVV, ocular torsion, and symptoms of nausea in a normal population; (b) the physiologic output of the utricle by comparing magnitude differences in SVV and ocular torsion as the degree of centrifugal stimulation changes in a normal population; (c) the effects of age on SVV and ocular torsion in a normal population and; (d) utricular function in individuals with a significant caloric weakness. Study sample. Thirty one normal controls and five individuals with unilateral vestibular hypofunction participated in the study. Normal participants were characterized by having normal hearing sensitivity, no history of neurologic or balance/dizziness involvement and negative results on a direct office vestibular examination. Unilateral vestibular hypofunction was defined as an asymmetry \u3e 30% on caloric testing. Intervention. Unilateral centrifugation was completed at 300°/sec using various lateral translation distances. Data collection and analysis. Non-parametric statistics were used for data analyses. Correlation analyses were completed with Spearman’s correlation. Within subjects’ comparisons were completed using Wilcoxon. Between subjects’ comparisons were completed using Mann Whitney U. Results. There was no significant difference in ocular torsion, SVV, or level of nausea between methods of lateral translation. Systematic changes in ocular torsion and SVV occurred with changes in degree of centrifugal stimulation throughout the study. There was no significant difference in ocular torsion or SVV between age groups. One subject with unilateral vestibular hypofunction demonstrated a significantly different regression slope. Conclusion. Either method of lateral translation effectively assesses unilateral utricular function. Age does not appear to have a significant effect on outcome parameters during unilateral centrifugation. Further investigation in diagnosing utricular dysfunction in specific patient populations is needed

Gender-based comorbidity in benign paroxysmal positional vertigo.

It has been noted that benign paroxysmal positional vertigo (BPPV) may be associated with certain disorders and medical procedures. However, most studies to date were done in Europe, and epidemiological data on the United States (US) population are scarce. Gender-based information is even rarer. Furthermore, it is difficult to assess the relative prevalence of each type of association based solely on literature data, because different comorbidities were reported by various groups from different countries using different patient populations and possibly different inclusion/exclusion criteria. In this study, we surveyed and analyzed a large adult BPPV population (n = 1,360 surveyed, 227 completed, most of which were recurrent BPPV cases) from Omaha, NE, US, and its vicinity, all diagnosed at Boys Town National Research Hospital (BTNRH) over the past decade using established and consistent diagnostic criteria. In addition, we performed a retrospective analysis of patients' diagnostic records (n = 1,377, with 1,360 adults and 17 children). The following comorbidities were found to be significantly more prevalent in the BPPV population when compared to the age- and gender-matched general population: ear/hearing problems, head injury, thyroid problems, allergies, high cholesterol, headaches, and numbness/paralysis. There were gender differences in the comorbidities. In addition, familial predisposition was fairly common among the participants. Thus, the data confirm some previously reported comorbidities, identify new ones (hearing loss, thyroid problems, high cholesterol, and numbness/paralysis), and suggest possible predisposing and triggering factors and events for BPPV

Age and gender distribution of BPPV survey participants (n = 227 total) (A), BPPV cases diagnosed at BTNRH in 2002–2011 (n = 1,377 total) (B), and Nebraska population in year 2010 (n = 1,826,341 total) [73] (C). Recurrent cases are counted only once (the first occurrence).

<p>Age and gender distribution of BPPV survey participants (n = 227 total) (A), BPPV cases diagnosed at BTNRH in 2002–2011 (n = 1,377 total) (B), and Nebraska population in year 2010 (n = 1,826,341 total) <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0105546#pone.0105546-USCensus1" target="_blank">[73]</a> (C). Recurrent cases are counted only once (the first occurrence).</p

Incidents and conditions immediately preceding the first BPPV symptoms.

<p>Only those who answered “yes” or “no” were included in the total or subtotal to obtain the percentages. Those who answered “does not apply” or “do not know/remember” were not included in the presented percentages.</p><p>Incidents and conditions immediately preceding the first BPPV symptoms.</p

Family history of BPPV.

<p>Family history of BPPV.</p