Richard A. Roberts

Prevalence of vestibulopathy in benign paroxysmal positional vertigo patients with and without prior otologic history Prevalencia de vestibulopatía en pacientes con vértigo postural paroxístico benigno (BPPV), con y sin historia previa de patología otológica

The purpose of this study was to determine the prevalence of reduced or absent labyrinthine reactivity (vestibulopathy) in two groups of participants with posterior canal BPPV. One group had prior diagnosis of otologic disease (positive history group). No one in the second group had ever been diagnosed with otologic disease (negative history group). Caloric responses were retrospectively analyzed for the two groups. Patients with a positive history exhibited a greater prevalence of vestibulopathy than patients with a negative history. The positive history group, on average, also exhibited a larger unilateral weakness than those patients in the negative history group. We conclude that patients with BPPV and a history of otologic disease are more likely to present with vestibulopathy, than patients with BPPV and no history of otologic disease. This finding supports the benefit of complete vestibular evaluation in patients with BPPV to ensure comprehensive and successful treatment outcome.

An adaptive clinical test of temporal resolution: Within-channel and across-channel gap detection

Abstract Objective: Several methods exist to measure temporal resolution in a clinical setting. The Adaptive Tests of Temporal Resolution (ATTR©) are unique in that they incorporate an adaptive psychophysical procedure to present stimuli via computer sound card. The purpose of this study was to determine if ATTR gap detection thresholds (GDTs) were stable across presentation levels (80 dB SPL, listener-selected level) and sound cards (high-end, inexpensive). Design: GDTs were measured using three conditions of the ATTR: broad-band noise within-channel (BBN-WC), narrowband noise within-channel (NBN-WC), and narrowband noise across-channel (NBN-AC). Analysis of the acoustical properties of ATTR stimuli was made by measuring the electrical signals produced by each sound card. Study Sample: Participants were 30 young adults with normal hearing. Results: The ATTR GDTs did not differ between presentation levels for all three stimulus conditions. Also, neither ATTR stimuli nor ATTR GDTs differed between sound cards for all conditions. Conclusions: The ATTR may be used in a clinical setting with a relatively inexpensive sound card and listener-selected levels. Normative performance values for each ATTR condition are provided. Sumario Objetivo: Existen varios métodos en la clínica para medir la resolución temporal. La prueba adaptativa para la resolución temporal (ATTR@) es u´nica en el sentido en que incorpora un procedimiento psico-físico para presentar estímulos por medio de una tarjeta de sonidos de una computadora. El propósito de este estudio fue determinar si los umbrales de detección de brechas (GDT) de la ATTR eran estables en diferentes niveles de presentación (80 dB SPL, nivel seleccionado por el oyente) y con diferentes tarjetas de sonido (hig-end, barata). Diseño: Los GDT fueron medidos en tres condiciones de ATTR: banda ancha, ruido en el canal (BBN-WC), ruido de banda angosta en el canal (NBN-WC) y ruido de banda angosta a través del canal (NBN-AC). El análisis de las propiedades acústicas de los estímulos de ATTR fue realizado midiendo las señales eléctricas producidas por cada tarjeta de sonido. Muestra: Los participantes fueron 30 adultos jóvenes con audición normal. Resultados: Los GDT ATTR no difirieron en los niveles de presentación en las tres condiciones de estímulo. Además, ni los estímulos de ATTR ni los GDT ATTR difirieron en con las diferentes tarjetas de sonido en todas las condiciones. Conclusiones: Los ATTR pueden ser utilizados en condiciones clínicas con una tarjeta de sonido relativamente barata y a niveles seleccionados por el oyente. Se proporcionan los valores normativos de desempeño para cada condición de ATTR.

An adaptive clinical test of temporal resolution: Age effects

Abstract Objective: Children with auditory processing disorder, as well as older adults with and without hearing loss, often report difficulty understanding speech in the presence of noise. There is evidence that deficient temporal resolution contributes to this difficulty. The purpose of this study was to establish within-channel (WC) and across-channel (AC) gap detection thresholds (GDTs) for participants ages 7 to 84 years. Design: GDTs were measured using narrow-band noise markers for two conditions of the Adaptive Tests of Temporal Resolution (ATTR): WC and AC. Study Sample: Participants were 29 children (ages 7-12 years) with normal hearing, 30 younger adults (ages 22-41 years) with normal hearing, and 60 older adults (ages 50 to 84 years) with varying hearing sensitivity. Results: GDTs are smallest and least variable for younger adults with normal hearing and are largest and most variable for the youngest children (ages 7-8 years). The GDTs of the other groups fell between those of the younger adults and youngest children. Group differences were more apparent for AC than WC conditions. Conclusions: WC and AC gap detection ability changes across the lifespan. The ATTR is an efficient tool for the assessment of temporal resolution at both ends of the lifespan. Sumario Objetivo: Los niños con trastornos en el procesamiento auditivo, así como los adultos con o sin hipoacusia, frecuentemente reportan dificultades para entender el lenguaje en presencia de ruido. Existe evidencia que las deficiencias en la resolución temporal contribuyen a esta dificultad. El propósito de este estudio fue establecer los umbrales de detección de brechas (GDT) dentro de los canales (WC) y a través de los canales (AC) para los participantes con edades entre 7 y 84 años. Diseño: Los GDT se midieron usando marcadores de ruido de banda estrecha para dos condiciones con la Prueba Adaptativa de Resolución Temporal (ATTR): WC y AC. Muestra: Los participantes fueron 29 niños (edades de 7 a 12 años) con audición normal, 30 adultos jóvenes (edades 22 a 41 años) con audición normal y 60 adultos mayores (edades de 50 a 84 años) con diferentes niveles de audición. Resultados: Los GDT son más pequeños y menos variables en los adultos jóvenes con audición normal, y más grandes y variables para en los niños pequeños (edades 7 a 8 años). Los GDT de los otros grupos se ubicaron entre los de los adultos jóvenes y los niños. Las diferencias grupales fueron más aparentes en la condición AC que en la WC. Conclusiones: La habilidad en la detección de brecha WC y AC cambia durante la vida. El ATTR es una herramienta eficiente para la evaluación de la resolución temporal en ambos extremos de la vida.

Differentiation of migrainous positional vertigo (MPV) from horizontal canal benign paroxysmal positional vertigo (HC-BPPV).

This article presents an approach to differentiation of migrainous positional vertigo (MPV) from horizontal canal benign paroxysmal positional vertigo (HC-BPPV). Such an approach is essential because of the difference in intervention between the two disorders in question. Results from evaluation of the case study presented here revealed a persistent ageotropic positional nystagmus consistent with MPV or a cupulolithiasis variant of HC-BPPV. The patient was treated with liberatory maneuvers to remove possible otoconial debris from the horizontal canal in an attempt, in turn, to provide further diagnostic information. There was no change in symptoms following treatment for HC-BPPV. This case was diagnosed subsequently as MPV, and the patient was referred for medical intervention. Treatment has been successful for 22 months. Incorporation of HC-BPPV treatment, therefore, may provide useful information in the differential diagnosis of MPV and the cupulolithiasis variant of HC-BPPV.

Computerized dynamic visual acuity with volitional head movement in patients with vestibular dysfunction.

Objectives: Patients with uncompensated vestibular dysfunction frequently report blurred vision during head movement, a symptom termed oscillopsia. One way to measure the functional deficit associated with an impaired vestibulo-ocular reflex is by comparing visual acuity from a baseline condition in which there is no head movement to visual acuity obtained during a dynamic condition with head movement. A previously described test incorporated a treadmill upon which patients walked during assessment of visual acuity. The objective of the current investigation was to evaluate an alternative method of assessing dynamic visual acuity that uses volitional head movement instead of walking on a treadmill. Methods: Fifteen participants with normal vestibular function and 16 participants with impaired vestibular function were enrolled. All participants performed the visual acuity task under baseline conditions with no movement and also under dynamic conditions that included 1) walking on a treadmill and 2) volitionally moving their head in the vertical plane. Results: No difference in performance was observed between the treadmill task and the volitional head movement task. Participants with impaired vestibular function performed more poorly under the dynamic conditions than did participants with normal vestibular function. Conclusions: The results suggest that the volitional head movement paradigm may be useful in identification of patients with functional deficits of the vestibulo-ocular reflex.

Effects of hearing loss on echo thresholds.

Objective The purpose of this investigation was to determine the effects of hearing loss on the perception of echoes. Design Echo thresholds were measured for eight listeners with normal hearing and nine listeners with impaired hearing. Pairs of 4-msec noise bursts were presented to each listener with onset-to-onset delays ranging from 2 to 16 msec. Echo thresholds were obtained at signal presentation levels of 10, 20, 30, 40, and 50 dB SL. Results Results revealed differences between the psychometric functions of the two subject groups. Psychometric functions of the subjects with impaired hearing indicated higher echo thresholds than for the subjects with normal hearing. In addition, echo thresholds at 10 dB SL were significantly higher than echo thresholds measured at 40 dB SL for both subject groups. Conclusion Listeners with impaired hearing exhibit higher echo thresholds than listeners with normal hearing. The higher echo thresholds for listeners with impaired hearing may account, at least in part, for difficulty on tasks such as localization in everyday listening environments.

Utility Measures of Health-Related Quality of Life in Patients Treated for Benign Paroxysmal Positional Vertigo

Objectives: Comparing the effects of different disorders and interventions on health-related quality of life (HRQoL) is important for healthcare policy and accountability. There are two basic approaches to measure HRQoL: questionnaires derived from psychometrics and preference-based measures or utilities derived from econometrics. While disease-specific HRQoL questionnaires, such as the Dizziness Handicap Inventory (DHI), are important because they focus on the impact of a specific problem and its treatments (i.e., vestibular disorders), economic comparisons of the impacts of diseases/disorders and their treatments are typically based on utility assessment. The utility measures for audiology application (UMAA) were developed to measure utilities for various audiologic conditions using a standard computer. The purpose of this study was to determine if the UMAA provides stable, valid, and sensitive utility measures of the effects of benign paroxysmal positional vertigo (BPPV) and its treatment on HRQoL. It was hypothesized that utilities, as measured by the UMAA, would indicate improvement in HRQoL post-treatment for BPPV comparable to a disease-specific health status measure (DHI). Design: The UMAA incorporates three techniques to measure utility: rating scale, standard gamble, and time tradeoff. A utility is a cardinal measure of strength of preference and is measured on a continuum basis from 0.0 (incapacitating dizziness) to 1.0 (no dizziness). Fifty-two adults with BPPV of the posterior semicircular canal completed the UMAA and DHI before treatment and again post-treatment. A subgroup of 15 participants completed the UMAA on two occasions before treatment to assess test-retest stability and to establish critical difference values. Results: Results from this investigation demonstrate that utilities as measured through the UMAA are stable, valid, and comparable to the DHI. Post-treatment utilities were also significantly higher than pretreatment utilities, indicating that the utilities, as measured through the UMAA, are sensitive to improvement in HRQoL after BPPV treatment. Conclusions: Utilities as measured through the UMAA seem sensitive to changes in HRQoL after treatment of BPPV. Since the UMAA can be used to measure patient preference (i.e., utility), it may be useful for comparison of specific audiologic conditions, such as BPPV, to nonaudiologic conditions, such as cardiovascular disease and kidney disease.

Effects of reverberation on fusion of lead and lag noise burst stimuli

The purpose of this investigation was to determine the effects of reverberation on the precedence effect by obtaining thresholds for perception of leading and lagging noise burst stimuli as separate auditory events. In Experiment 1, lag burst thresholds for 4-ms noise bursts were measured in a simulated reverberant and anechoic environment for nine subjects with normal hearing at presentation levels of 10, 20, and 30 dB SL. Results indicated that lag burst thresholds obtained in the reverberant environment were higher than those obtained in the anechoic environment, with no effect of sensation level. In Experiment 2, three new stimulus conditions, two monaural and one binaural control, were employed. For one monaural condition, the stimuli were equal in level and for the other, the leading stimulus was more intense than the lagging stimulus. For the binaural control condition, the stimuli were presented from a perceived spatial location of 0 degrees azimuth. In the monaural and binaural control conditions, lag burst thresholds were lower than those obtained in the reverberant environment of Experiment 1. There was no difference between lag burst thresholds obtained in either environment for the monaural and binaural control conditions compared to the anechoic condition of Experiment 1. Results of Experiment 2 indicate that the higher lag burst thresholds observed in Experiment 1 are not fully explained by a peripheral masking effect.

Teaching Patient-Centered Counseling Skills for Assessment, Diagnosis, and Management of Benign Paroxysmal Positional Vertigo

Audiologists are an integral part of the management of those with dizziness and vestibular disorders. However, little research has been performed on counseling approaches for patients who present with dizziness as a primary concern. Accordingly, it is important that audiology students are provided with didactic and experiential learning opportunities for the assessment, diagnosis, and management of this population. Benign paroxysmal positional vertigo is the most common vestibular disorder among adults. Doctor of Audiology students, at a minimum, should be provided with learning opportunities for counseling patients with this particular disorder. Implementation of patient-centered counseling is applied across various parts of the patient encounter from initial intake to treatment and patient education. The purpose of this article is to present the available evidence and to apply widely accepted theories and techniques to counseling those with benign paroxysmal positional vertigo. Didactic resources and experiential learning activities are provided for use in coursework or as a supplement to clinical education.

Anterior Canal benign paroxysmal positional Vertigo following surgical Management of superior canal dehiscence

OBJECTIVE Benign paroxysmal positional vertigo (BPPV) is a common post-surgical finding in patients managed for superior semicircular canal dehiscence (SSCD). The posterior semicircular canal has been reported as the involved canal in the majority of cases of post-surgical BPPV, with only two cases reported of lateral canal involvement. The objective of this report is to present a case in which an anterior semicircular canal BPPV response was identified in a patient following surgical management for SSCD. METHOD This case report presents an adult with residual dizziness following surgical management of SSCD and vestibular rehabilitation therapy (VRT). During subsequent evaluation of vestibular function, a transient and torsional, down-beating nystagmus was provoked along with vertigo during Dix-Hallpike positioning to the right. This was consistent with BPPV affecting the left superior (anterior) semicircular canal. RESULTS The patient was treated with a repositioning maneuver to manage anterior semicircular canal BPPV and no nystagmus response was recorded with post-repositioning Dix-Hallpike test. Review of radiographic images, obtained prior to vestibular function testing, showed a hyperintensity in the area of the left anterior semicircular canal ampulla. It was felt this was likely a bone chip from the SSCD repair that was pushing against the ampulla with further mobile debris within the canal. CONCLUSION It is reported that BPPV is a common complication in patients surgically managed for SSCD. Posterior semicircular canal BPPV is reported most often, with a couple of cases of lateral semicircular canal BPPV also reported. As far as we are aware, the current case represents the first report of anterior semicircular canal BPPV in this type of patient.