Bilateral Vestibular Dysfunction

Bilateral vestibular dysfunction (BVD) refers to hypofunction of the vestibular nerves or labyrinths on both sides. Patients with BVD present with dizziness, oscillopsia, and unsteadiness, mostly during locomotion, which worsen in darkness or on uneven ground. Although aminoglycoside ototoxicity, Meniere's disease, infection, and genetic disorders frequently cause BVD, the etiology remains undetermined in up to 50% of the patients. The diagnosis of BVD requires both symptoms and documentation of deficient vestibulo-ocular reflex function using head-impulse, bithermal caloric, and rotatory chair tests. Since various neurologic and systemic disorders may present with BVD, clinicians should be cautious not to overlook the symptoms and signs of central nervous system and systemic involvements. Vestibular rehabilitation, application of vibrotactile and auditory feedbacks, and vestibular prosthesis can aid the patients with BVD along with the correction of the underlying causes.

A Distinctive Platform System to Study the Effects of a Vestibular Prosthesis on Nonhuman Primate Postural Control

The purpose of this paper is to describe novel experiments and methodologies utilizing a distinctive balance platform system to investigate postural responses for moderate to severe vestibular loss and invasive vestibular prosthesis-assisted nonhuman primates (rhesus monkeys). For several millions of vestibular loss sufferers in the U.S., daily living is severely affected in that common everyday tasks, such as getting out of bed at night, maintaining balance on a moving bus, or walking on an uneven surface, may cause a loss of stability leading to falls and injury. Aside from loss of balance, blurred vision and vertigo (perceived spinning sensation) are also debilitating in vestibular-impaired individuals. Although the need for vestibular rehabilitative solutions is apparent, postural responses for a broad range of peripheral vestibular function, and for various stationary and moving support conditions, have not been systematically investigated. For the investigation of implants and prostheses that are being developed toward implementation in humans, nonhuman primates are a key component. The measurement system used in this research was unique. Our platform system facilitated the study of rhesus monkey posture for stationary support surface conditions (quiet stance and head turns) and for dynamic support surface conditions (pseudorandom roll tilts of the support surface). Further, the platform system was used to systematically study postural responses that will serve as baseline measures for future vestibular-focused human and nonhuman primate posture studies.

A Novel Platform-System to Study the Effects of a Vestibular Prosthesis on Non-Human Primate Postural Control

For the several millions of vestibular loss sufferers nationwide, daily-living is severely affected in that common everyday tasks, such as getting out of bed at night, maintaining balance on a moving bus, or walking on an uneven surface, may cause loss of stability leading to falls and injury. Aside from loss of balance, blurred vision and vertigo (perceived spinning sensation) are also extremely debilitating in vestibular impaired individuals. For the investigation of implants and prostheses that are being developed towards implementation in humans, non-human primates are a key component. The purpose of our study was to implement a distinctive balance platform-system to investigate postural responses for moderate to severe vestibular loss and invasive vestibular prosthesis-assisted non-human primates (rhesus monkeys) for test balance conditions of various task-difficulty levels. Although the need for vestibular rehabilitative solutions is apparent, postural responses for a broad range of peripheral vestibular function, and for various stationary and moving support conditions, have not been systematically investigated. The measurement system used in this research was unique in that it allowed us to conduct animal experiments, not investigated previously; such experiments are necessary towards the development on an invasive vestibular prosthesis to be used in humans suffering from vestibular loss. Our platform-system facilitated the study of rhesus monkey posture for stationary support surface conditions (i.e., quiet stance and head turns; more versus fewer footplate cues and large versus small base-of-support) and for dynamic support surface conditions (i.e., pseudorandom roll-tilts of the support surface). Further, the platform-system was used to systematically study postural responses that will serve as baseline measures for future vestibular-focused human and non-human primate posture studies.