The Impact of Sleep Deprivation on Video Head Impulse Test Results.

Objective: To investigate the association between sleep deprivation and vestibular dysfunction by Video Head Impulse Test (vHIT).

Methods: This prospective clinical trial explores the impact of acute sleep deprivation on the vestibular-ocular reflex (VOR) in medical residents. The study involved healthy physicians from diverse medical disciplines.

Bilateral vestibulopathy as the initial presentation of CANVAS.

Cerebellar ataxia with neuropathy and vestibular areflexia syndrome (CANVAS) is a slowly progressing autosomal recessive ataxic disorder linked to an abnormal biallelic intronic (most commonly) AAGGG repeat expansion in the replication factor complex subunit 1 (RFC1). While the clinical diagnosis is relatively straightforward when the three components of the disorder are present, it becomes challenging when only one of the triad (cerebellar ataxia, neuropathy or vestibular areflexia) manifests. Isolated cases of Bilateral Vestibulopathy (BVP) or vestibular areflexia that later developed the other components of CANVAS have not been documented.

Barriers and Facilitators of Vestibular Rehabilitation: Patients and Physiotherapists' Perspectives.

Background And Purpose: Poor adherence to vestibular rehabilitation protocols is a known barrier to optimal care. Vestibular clinicians' comprehensive understanding of the barriers and facilitators to vestibular home exercise programs (VHEP) is a key element to achieving optimal care in the context of vestibular rehabilitation. The aims of this study are as follows: (1) to identify primary barriers and facilitators to VHEP from the perspective of patients with vestibular dysfunction and vestibular physical therapists (PTs); and (2) to provide strategies for clinicians to improve adherence and outcomes of VHEP.

[EVALUATION OF THE DIZZY PATIENT - FROM THE VESTIBULAR IMPAIRMENT TO THE PATIENT'S FUNCTIONAL ABILITY].

The vestibular system - the sixth sense - allows humans to preserve balance, stable vision, and body orientation in space. This system performs a continuous integration of the activity of the vestibular end-organ in the inner ear, the sense of sight, and the proprioceptive sense. Damage to the components of the vestibular system causes dizziness, imbalance, and poor orientation in space.

[SLEEP HABIT MODIFICATION AS A POSSIBLE PREVENTION OF RECURRENT BENIGN PAROXYSMAL POSITIONAL VERTIGO].

Background: Benign paroxysmal positional vertigo (BPPV) is effectively treated with a variety of repositioning maneuvers but one-third to one-half of patients experience recurrence, usually within 2 years after the first attack.

Objectives: The aim of this study was to investigate possible prevention of recurrent BPPV by sleep habit modification.

Methods: Patients diagnosed with posterior semicircular canal BPPV (p-BPPV) were asked their preferred lying side during nocturnal sleep.

Binocular Alignment Changes Between Sitting and Supine Positions in Patients with Dizziness.

Vertical and torsional ocular misalignment can occur from mild traumatic brain injury or inner ear pathology, which may vary depending on head position. Here, we evaluate differences in a behavioral measure of binocular alignment in both upright and supine head position. Ocular perception of vertical and torsional alignment was measured using the torsional and vertical alignment nulling (TAN, VAN) task in N = 52 veterans with dizziness (N = 38 with traumatic brain injury), N = 41 civilians with vestibular schwannoma resection (UVD), and N = 33 healthy controls for both positions.

The Instrumented Timed "Up & Go" Test Distinguishes Turning Characteristics in Vestibular Hypofunction.

Objective: Deficits in vestibular function increase the risk for falls while turning. However, the clinical assessment of turning in patients with vestibular dysfunction is lacking, and evidence is limited that identifies the effectiveness of vestibular physical therapy in improving turning performance. The purpose of this study was to quantify walking and turning performance during the instrumented Timed "Up & Go" (TUG) test using body-worn inertial measurement units (IMUs).

Posture, Gait, Quality of Life, and Hearing with a Vestibular Implant.

Background: Bilateral vestibular hypofunction is associated with chronic disequilibrium, postural instability, and unsteady gait owing to failure of vestibular reflexes that stabilize the eyes, head, and body. A vestibular implant may be effective in alleviating symptoms.

Methods: Persons who had had ototoxic (7 participants) or idiopathic (1 participant) bilateral vestibular hypofunction for 2 to 23 years underwent unilateral implantation of a prosthesis that electrically stimulates the three semicircular canal branches of the vestibular nerve.

Improvement After Vestibular Rehabilitation Not Explained by Improved Passive VOR Gain.

Gaze stability exercises are a critical component of vestibular rehabilitation for individuals with vestibular hypofunction and many studies reveal the rehabilitation improves functional performance. However, few studies have examined the vestibular physiologic mechanisms (semicircular canal; otolith) responsible for such recovery after patients with vestibular hypofunction complete gaze and gait stability exercises. The purpose of this study was to compare behavioral outcome measures (i.

Continuous vestibular implant stimulation partially restores eye-stabilizing reflexes.

BACKGROUNDBilateral loss of vestibular (inner ear inertial) sensation causes chronically blurred vision during head movement, postural instability, and increased fall risk. Individuals who fail to compensate despite rehabilitation therapy have no adequate treatment options. Analogous to hearing restoration via cochlear implants, prosthetic electrical stimulation of vestibular nerve branches to encode head motion has garnered interest as a potential treatment, but prior studies in humans have not included continuous long-term stimulation or 3D binocular vestibulo-ocular reflex (VOR) oculography, without which one cannot determine whether an implant selectively stimulates the implanted ear's 3 semicircular canals.

Vestibular Testing-Rotary Chair and Dynamic Visual Acuity Tests.

The human vestibular system is exquisitely sensitive to detect linear and rotational head acceleration signals, processed in the brainstem and subsequently relayed to the extraocular motor neurons to generate a compensatory eye rotation. This vestibulo-ocular reflex (VOR) ensures clear and stable vision during head rotation, enabling humans to keep gaze on their desired target. In this chapter, we describe the rotary chair - one physiologic measure of the VOR, and the dynamic visual acuity (DVA) test - one behavioral measure of the VOR.

Using Inertial Sensors to Quantify Postural Sway and Gait Performance during the Tandem Walking Test.

Vestibular dysfunction typically manifests as postural instability and gait irregularities, in part due to inaccuracies in processing spatial afference. In this study, we have instrumented the tandem walking test with multiple inertial sensors to easily and precisely investigate novel variables that can distinguish abnormal postural and gait control in patients with unilateral vestibular hypofunction. Ten healthy adults and five patients with unilateral vestibular hypofunction were assessed with the tandem walking test during eyes open and eyes closed conditions.

VOR adaptation training and retention in a patient with profound bilateral vestibular hypofunction.

A novel training method known as incremental VOR adaptation (IVA) can improve the vestibulo-ocular reflex (VOR) gain for both active and passive head rotation by coupling active head rotations with a laser-projected target that moves in the opposite direction of the head at a fraction of the head velocity. A 51-year-old male with bilateral vestibular hypofunction participated in a research protocol using a portable IVA device for 645 days. Passive VOR gains improved 179% to 600%; standing posture and gait also improved.

Veterans have greater variability in their perception of binocular alignment.

Introduction: A significant population of our wounded veterans suffer long-term functional consequences of visual deficit, disorientation, dizziness, and an impaired ability to read. These symptoms may be related to damage within the otolith pathways that contribute to ocular alignment. The purpose of this study was to compare perception of vertical and torsional ocular alignment between veterans and healthy controls in an upright and supine test position.

Exposure to an extreme environment comes at a sensorimotor cost.

Long duration space flight is known to induce severe modifications in the sensorimotor and musculoskeletal systems. While in-flight strategies including physical fitness have been used to prevent the loss of bone and muscle mass using appropriate rehabilitative countermeasures, less attention has been put forth in the design of technologies that can quickly and effectively assess sensorimotor function during missions in space. The aims of the present study were therefore (1) to develop a Portable Sensorimotor Assessment Platform (PSAP) to enable a crewmember to independently and quickly assess his/her sensorimotor function during the NASA's Extreme Environment Mission Operations (NEEMO) and (2) to investigate changes in performance of static posture, tandem gait, and lower limb ataxia due to exposure in an extreme environment.

Simultaneous and opposing horizontal VOR adaptation in humans suggests functionally independent neural circuits.

The healthy vestibulo-ocular reflex (VOR) ensures that images remain on the fovea of the retina during head rotation to maintain stable vision. VOR behavior can be measured as a summation of linear and nonlinear properties although it is unknown whether asymmetric VOR adaptation can be performed synchronously in humans. The purpose of the present study is twofold.

The inter-observer reliability and agreement of lateral balance recovery responses in older and younger adults.

The purpose of this study was to evaluate the inter-observer reliability and agreement of balance recovery responses, step and multiple-steps thresholds, and kinematic parameters of stepping responses. Older and younger adults were exposed to 36 progressively challenging right and left unannounced surface translations during quiet standing. Subjects were instructed to "react naturally".

A Tool to Quantify the Functional Impact of Oscillopsia.

Background: Individuals with bilateral vestibular hypofunction (BVH) often report symptoms of oscillopsia during walking. Existing assessments of oscillopsia are limited to descriptions of severity and symptom frequency, neither of which provides a description of functional limitations attributed to oscillopsia. A novel questionnaire, the Oscillopsia Functional Impact scale (OFI) was developed to describe the impact of oscillopsia on daily life activities.

Perturbation exercises during treadmill walking improve pelvic and trunk motion in older adults-A randomized control trial.

Background: Most falls among older adults occur while walking. Pelvic and trunk motions are required to maintain stability during walking. We aimed to explore whether training that incorporates unexpected loss of balance during walking that evokes balance recovery reactions will improve pelvic, thorax, and trunk kinematics at different walking speeds.

Gait Coordination Deteriorates in Independent Old-Old Adults.

Human gait is symmetric and bilaterally coordinated in young healthy persons. In this study, we aimed to explore the differences in bilateral coordination of gait as measured by the phase coordination index (PCI), gait asymmetry, and stride time variability of gait between four age groups. A total of 44 older adults were recruited: nine young-old (age 70-74 years), 26 old (age 75-84 years), nine old-old (>85 years and older), and 13 young adults (age 20-30 years).

Central not peripheral vestibular processing impairs gait coordination.

Gait coordination is generated by neuronal inter-connections between central pattern generators in the spinal cord governed by cortical areas. Malfunction of central vestibular processing areas generates vestibular symptoms in the absence of an identifiable peripheral vestibular system lesion. Walking in the dark enforces a coordinated afference primarily from the vestibular and somatosensory systems.

Old adult fallers display reduced flexibility of arm and trunk movements when challenged with different walking speeds.

Specific patterns of pelvic and thorax motions are required to maintain stability during walking. This cross-sectional study explored older-adults' gait kinematics and their kinematic adaptations to different walking speeds, with the purpose of identifying mechanisms that might be related to increased risk for falls. Fifty-eight older adults from self-care residential facilities walked on a treadmill, whose velocity was systematically increased with increments of 0.

Unexpected perturbations training improves balance control and voluntary stepping times in older adults - a double blind randomized control trial.

Background: Falls are common among elderly, most of them occur while slipping or tripping during walking. We aimed to explore whether a training program that incorporates unexpected loss of balance during walking able to improve risk factors for falls.

Methods: In a double-blind randomized controlled trial 53 community dwelling older adults (age 80.

Application of the clinical version of the narrow path walking test to identify elderly fallers.

Introduction: Falling during walking is a common problem among the older population. Hence, the challenge facing clinicians is identifying who is at risk of falling during walking, for providing an effective intervention to reduce that risk. We aimed to assess whether the clinical version of the narrow path walking test (NPWT) could identify older adults who are reported falls.