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Background: The otoliths act as gravito-inertial force sensors and contribute to the perception of spatial orientation. The perception of gravitational vertical can be assessed by asking a subject to adjust a light bar to the vertical. Prior to clinical use of the SVV (subjective visual vertical) test, normative data and test-retest reliability must be established. Purpose: To obtain normative data and d etermine the test-retest reliability for the SVV test performed in static and dynamic test conditions. Research Design: A descriptive design was used to obtain normative data. Study Sample: Twenty-four young adults with no history of neurological disease, middle-ear pathology, open or closed head injury, cervical injury, or audiovestibular disorder participated in the study. Data Collection and Analysis: The SVV angle was measured in the static position and in three dynamic conditions: (1) on-axis clockwise (CW) rotation, (2) off-axis CW rotation of right ear, and (3) off-axis CW rotation of left ear. Results: In young healthy individuals, the SVV was Conclusions: The normative data obtained in this study may be useful in identifying patients with chronic utricular dysfunction. We recommend the use of difference angles (on-axis SVV ‐ off-axis SVV) to remove baseline bias and decrease the variability of the SVV angles for the off-axis conditions.

Objective: The purpose of this study was to investigate the effects of noise exposure on the cervical vestibular evoked myogenic potential (cVEMP) in individuals with asymmetric noise-induced sensorineural hearing loss (NIHL). Design: A cross-sectional observational study was used to compare cVEMP characteristics in 43 individuals with a history of noise exposure greater in one ear (e.g., the left ear of a right-handed rifle shooter) and asymmetric sensorineural hearing loss consistent with the history of noise exposure and in 14 age-matched controls. The characteristics of hearing loss were examined further for the noise-exposed participants with abnormal cVEMPs and the noise-exposed participants with normal cVEMPs. Results: Thirty-three percent of the noise-exposed participants had abnormal cVEMPs, whereas cVEMPs were present and symmetrical in 100% of the age-matched controls, and cVEMP threshold was greater in the noise-exposed group than in the control group. Abnormal cVEMPs occurred most often in the ears with poorer hearing (or greater NIHL), and the noise-exposed participants who had abnormal cVEMPs had poorer high-frequency pure-tone thresholds (greater NIHL) and greater interaural high-frequency pure-tone threshold differences than the noise-exposed participants with normal cVEMPs. Conclusions: These findings are consistent with previous studies that suggest that the sacculocollic pathway may be susceptible to noise-related damage. There is emerging evidence that the severity of NIHL is associated with the presence or absence of cVEMPs.

Objective: The objective of the present study was to evaluate the performance of the monothermal caloric screening test in a large sample of patients. Design: A retrospective analysis of the medical records of 1002 consecutive patients who had undergone vestibular assessment at the Mayo Clinic during the years 1989 and 1990 was conducted. Patients with incomplete alternate binaural bithermal (ABB) caloric testing, congenital or periodic alternating nystagmus, or bilateral vestibular loss were excluded from the study. Clinical decision theory analyses (relative operating characteristic curves) were used to determine the accuracy with which the monothermal warm (MWST) and monothermal cool (MCST) caloric screening tests predicted the results of the ABB caloric test. Cumulative distributions were constructed as a function of the cutoff points for monothermal interear difference (IED) to select the cutoff point associated with any combination of true-positive and false-positive rates. Results: Both MWST and MCST performed well above chance level. The test performance for the MWST was significantly better than that of the MCST for three of the four ABB gold standards. A 10% IED cutoff point for the MWST yielded a false-negative rate of either 1% (UW ≥25%) or 3% (UW ≥20%). The use of a 10% IED (UW ≥25%) for the MWST would have resulted in a 40% reduction (N = 294) in the number of ABB caloric tests performed on patients without a unilateral weakness. Conclusions: The results of this study indicated that the MWST decreases test time without sacrificing the sensitivity of the ABB caloric test.

Cervical vestibular-evoked myogenic potentials (cVEMPs) are recorded from the sternocleidomastoid muscle using air conduction or bone conduction acoustic stimuli, skull taps, or transmastoid current. The diagnostic usefulness of the cVEMP has been examined for various peripheral and central vestibulopathies. Recent reports indicate that it is possible to record short-latency ocular vestibular-evoked myogenic potentials (oVEMPs) from surface electrodes below the eyes in response to air conduction and bone conduction stimuli. Both methods provide diagnostic information about otolith function. This article provides an overview of each method and highlights the similarities and differences. Several cases are presented to illustrate the relation between the results for cVEMPs and oVEMPs in patients with well-defined audiovestibular disorders.

Background: The Mountain Home Veterans Affairs (VA) Medical Center has been diagnosing and treating veterans with benign paroxysmal positional vertigo (BPPV) for almost 2 decades. The clinic protocol includes a 2-week follow-up visit to determine the treatment outcome of the canalith repositioning treatment (CRT). To date, the characteristics of BPPV and treatment efficacy have not been reported in a cohort of veterans with BPPV. Purpose: To determine the prevalence and characteristics of veterans diagnosed with BPPV in a Veterans Affairs Medical Center Audiology Clinic and to examine treatment outcomes. Research Design: Retrospective chart review. Study Sample: A total of 102 veterans who tested positive for BPPV in the Vestibular Clinic at the Mountain Home VA Medical Center from March 2010 to August 2011. Results: In 102 veterans who were diagnosed with BPPV, the posterior semicircular canal was most often involved (75%), motion-provoked vertigo was the most common symptom (84%), and the majority (43%) were diagnosed with BPPV in their sixth decade. The prevalence of BPPV in the Audiology Vestibular Clinic was 15.6%. Forty-one percent of veterans reported a symptom onset within 12 months of treatment for BPPV; however, 36% reported their symptoms began > 36 months prior to treatment. CRT was effective (negative Dix–Hallpike/roll test) in most veterans (86%) following 1 treatment appointment (M = 1.6), but more than half reported incomplete symptom resolution (residual dizziness) at the follow-up appointment. Eighteen percent of veterans experienced a recurrence (M = 1.8 years; SD = 1.7 years). Conclusions: The characteristics and treatment outcomes of BPPV in our veteran cohort was similar to what has been reported in the general population. Future work should focus on improving the timeliness of evaluation and treatment of BPPV and examining the time course and management of residual dizziness.

Adults with hearing loss typically experience difficulty understanding speech and report increased mental effort or listening effort (Pichora-Fuller et al. 2016). Over time, or in difficult listening conditions, listening effort can cause stress and mental fatigue, contributing to negative psychosocial consequences (e.g., social withdrawal) or limited/discontinued hearing-aid use (Eckert, et al., 2016; Pichora-Fuller, 2007). Additionally, the amount of listening effort required to recognize speech varies by individual and by listening condition (Pichora-Fuller, Kramer, Eckert, et al., 2016). Therefore, having a way to measure and account for listening effort in individual hearing aid fittings and aural rehabilitation plans may improve satisfaction and eventual hearing aid retention in those with hearing loss. Few objective measures are available to reliably predict listening effort in real world environments and many effort-related measures do not consider the specific neural systems that underlie listening effort (Zekveld et al., 2010; Smith et al. 2016; McMahon et al. 2016). The purpose of this study is to evaluate an electroencephalogram (EEG)-based method for quantifying listening effort based on the power of the cortical EEG response. Spectral power estimates within different EEG frequency domains that represent the activity of attention-related neural systems were calculated and included: (1) low-frequency alpha (8-10 Hz; LFA) power that has been associated with increased working memory task demands (Klimesch, 1999); (2) high-frequency alpha (10-13 Hz; HFA) power that has been associated with semantic memory and cognitive demands (Klimesch, 1999); and (3) theta (4-7 Hz) power that has been associated with encoding information (Klimesch, 1999) and increased listening effort (Wisniewski et al., 2015). The EEG data was collected during administration of the Words-In-Noise test (WIN; Wilson et al., 2003) and the Word Auditory Recognition and Recall Measure (WARRM; Smith et al., 2016) that induce listening effort due to low signal-to-noise ratio and due to auditory working memory demand, respectively. The results of correlations among EEG power in the three frequency ranges, WIN performance, WAARM performance, and self-report measures of listening effort will be presented. These results will be supported by independent component source analysis of EEG frequencies for regions of interest predicted to contribute to listening effort, including the frontal midline, auditory cortex, and parietal lobe. The EEG measures are expected to collectively explain task performance and self-reported listening effort.

Medial tibial stress syndrome (MTSS) is a stress and overuse injury that presents as pain on the medial aspect of the lower two-thirds of the tibia. It is most often caused by repetitive actions on hard surfaces such as running, marching, and dancing. Individuals most affected by MTSS are runners, members of the military, dancers, and athletes that play soccer, volleyball and basketball. While MTSS has a relatively standard presentation of pain on the medial aspect of the tibia, it can occasionally be mistaken for other injuries such as stress fractures or compartment syndrome. If a diagnosis is unsure, methods such as x-ray, bone-scan, and MRI can be utilized to better obtain the correct diagnosis. A variety of treatments exist for MTSS including, ice, massage, muscle strengthening, and rest. A combination of these various techniques is most often what is employed. In this study, the effectiveness of a set of resistance ankle exercises in combination with ice and massage was tested and compared to that of ice and massage alone. The hypothesis was that athletes receiving the exercises as part of their treatment, in addition to the icing and massaging, would have a greater decrease in pain from MTSS than athletes just receiving ice and massage as treatment. The exercises would strengthen the muscles of the lower leg that, when weak, can contribute to the development of MTSS. Results indicated that the exercises yielded a more significant decrease in pain from MTSS than ice and massage alone.

Musicians are a high-risk occupational group for musculoskeletal disorders. Often manifesting in muscle tension, pain and paresthesia, musculoskeletal disorders can drastically affect comfort, mentality and endurance while performing. This study sought to examine the effects of electromyography (EMG) biofeedback training in reducing musculoskeletal symptoms in music performance. The subjects were university-level violinists and cellists. Over a period of 2-4 weeks, all participants underwent EMG biofeedback training while performing their instrument using audio feedback. No significant results were found, but patterns of decreased muscle tension and increased performance comfort and endurance were observed.

The purpose of this investigation was to examine selected biochemical mechanisms known to influence contractility and energy metabolism in the myocardium, with particular emphasis placed on the regulatory role of protein phosphorylation in the ventricular myocardium. The investigation was conducted in three phases; initially the cardiac contraction cycle was examined to determine whether reported fluctuations in myocardial cAMP levels were associated with other biochemical events known to be cAMP-dependent. The second phase involved the determination of specific kinase activities and endogenous substrates in a highly purified cardiac sarcolemmal preparation. In the final phase, ventricular myocytes were utilized to examine the ability of adenosinergic and muscarinic agonists to influence the isoproterenol-induced increases in protein phosphorylation. Studies in the first phase examined cyclic AMP levels and selected kinase activities in hearts frozen at various stages of the cardiac cycle. An automated clamping device, capable of freezing a perfused rat heart in less than 50 msec, was utilized to separate the cardiac cycle into various phases. Three different timing schemes were employed to divide the cycle into 2 to 4 segments. These different timing schemes revealed no significant differences in cAMP during the cardiac cycle. Myocardial cAMP values ranged from 2.5 to 4.1 pmol/min/mg protein in all phases. However, in one scheme there was a tendency for cAMP to be elevated in early systole, with minimal values occurring diastole. There were also no significant differences seen for either glycogen phosphorylase or cAMP-dependent protein kinase (PKA) activity between various phases of the cardiac cycle. Since no significant fluctuations were observed in the levels of cAMP or the activities of PKA or glycogen phosphorylase during a single cardiac contraction cycle, it would appear that these agents do not exert their effects on cardiac function on a beat to beat basis. The second phase of study examined the nature and function of individual protein kinases in the myocardium. Using a highly purified cardiac sarcolemmal preparation, kinase specific, synthetic substrates were employed to quantify the activities of cAMP-dependent (PKA), calcium/calmodulin-dependent (PKCM), calcium/phospholipid-dependent (PKC) and cGMP-dependent (PKG) protein kinases. Additionally, endogenous protein substrates were examined in this preparation to provide possible insight as to the function of these kinases in the heart. The activities of PKA, PKG, PKCM, and PKC in nmol 32P/min/μg protein were as follows: PKA, 1606; PKG, 35.7; PKCM, 353; and PKC, 13.2. Three endogenous protein substrates of apparent molecular weights of 15kD, 28kD and 92kD were phosphorylated. While no endogenous protein phosphorylation was detectable as a result of cG-PK activity, all of the substrates were phosphorylated, to varying degrees, by both PKA and CACM-PK. PKC phosphorylated only the 15kD substrate. Even though several endogenous kinases are evident in the sarcolemmal preparation, cAMP-dependent protein kinase demonstrates the greatest degree of activity. This kinase also appeared to be the most abundant; however, there is some concern as to the source of these kinases in the membrane preparation since endothelial membranes as well as cardiac membranes appeared to be present. Evidence for endothelial contamination was provided by the finding that the membrane preparation contained appreciable amounts of angiotensin converting enzyme (ACE) activity, an enzyme felt to reside in the vascular endothelium. Since studies with this preparation could not exclude contribution of nonmuscle cell membranes a model consisting solely of dispersed ventricular myocytes was developed. The third phase of these studies examined protein phosphorylation in primary cultures of ventricular myocytes. Specifically, these studies examined protein phosphorylation induced by exposure to isoproterenol (ISO), a catecholamine known to effect changes in the phosphorylation state of proteins in the heart by means of a β-adrenergic-mediated/cAMP-dependent mechanism was examined. Additionally, the effects of phenylisopropy-ladenosine (PIA) and carbamyl choline chloride (CARB) were examined with regard to their anti-adrenergic role(s) in this process. Adherent, collagenase-dispersed, radiolabelled (32p) ventricular myocytes exposed to ISO demonstrated a dose and time dependent increase in 32p incorporation into several endogenous protein substrates. When the myocytes were exposed (60 sec) to either PIA or CARB prior to the exposure to ISO, ISO-induced 32p incorporation into protein substrates of apparent molecular weight of 6kD, 31kD and 155kD was reduced up to 67% when compared to the effects of ISO alone. Additionally, both PIA and CARB attenuated the ISO-induced increase in PKA activity in the myocyte, yet only CARB was seen to produce an inhibitory effect on the ISO-induced increase in cAMP levels in the myocytes. The effects of CARB were dose-dependent and inhibited the effects of ISO on 32p incorporation at all doses tested. PIA elicited biphasic effects: lower PIA concentrations were inhibitory in nature, while higher concentrations of PIA appeared to potentiate the increase in 32p incorporation induced by ISO. Based on electrophoretic mobilities (SDS/PAGE) of the 6kD and the 155kD substrates, these substrates have been tentatively identified as the monomeric form of the sarcoplasmic reticulum-associated protein, phospholamban, and the contractile filament-associated protein, C protein, respectively. The 31kD substrate has been identified, by means of immunoblot, as the contractile filament-associated protein, troponin I. The role of protein phosphorylation in the myocardium involves complex, inter-related mechanisms that encompass extracellular, transmembranal and cytoplasmic elements in the heart. It is well understood that certain mechanisms of the contraction cycle known to vary on a beat to beat basis, such as myosin ATPase, involve changes in protein phosphorylation. However, the nature of the various kinases and substrates examined in this study appear to influence longer-term events of myocardial contractility. Mechanisms coupled with hormone action, modulation of second messenger-dependent components, and factors associated with changes in contractility seen with aging and disease are more likely to exhibit changes similar to those described herein. A better understanding of the underlying biochemistry may provide greater insight into the importance of these metabolic changes.