Vestibulo-ocular Physiology Underlying Vestibular Hypofunction

Abstract

The vestibular system detects motion of the head and maintains stability of images on the fovea of the retina as well as postural control during head motion. Signals representing angular and translational motion of the head as well as the tilt of the head relative to gravity are transduced by the vestibular end organs in the inner ear. This sensory information is then used to control reflexes responsible for maintaining the stability of images on the fovea (the central area of the retina where visual acuity is best) during head movements. Information from the vestibular receptors also is important for posture and gait. When vestibular function is normal, these reflexes operate with exquisite accuracy and, in the case of eye movements, at very short latencies. Knowledge of vestibular anatomy and physiology is important for physical therapists to effectively diagnose and manage people with vestibular dysfunction. The purposes of this article are to review the anatomy and physiology of the vestibular system and to describe the neurophysiological mechanisms responsible for the vestibulo-ocular abnormalities in patients with vestibular hypofunction.

Effect of Vestibular Stimulation Exercises on Balance in Children With Down Syndrome

“…Disorders that affect vestibular function result in abnormalities in these reflexes and lead to sensations that reflect abnormal information about motion from the vestibular receptors (Schubert & Minor, 2004). Due to an abnormality in the 21 st chromosome the central nervous system is affected in a variety of ways (Galli et al, 2008).…”

“…Vestibular rehabilitation refers to interventions such as adaptation exercises, repositioning techniques, and exercises to improve muscle force, gait, or balance (Schubert & Minor, 2004). Appropriate activity programs for young children with DS are uncommon.…”

Potencial evocado miogênico vestibular ocular e cervical simultâneo em indivíduos normais

“…This is called ocular VEMP. Unlike the cervical VEMP that evaluates the descending ipsilateral vestibular pathway, the ocular VEMP evaluates the superior vestibular pathway: the ascending contralateral pathway (7)(8)(9)(10)(11)(12)(13)(14) .…”

Influência da fadiga no equilíbrio do pé de apoio de jogadores de futebol

“…As causas da fadiga muscular com a prática de esporte podem estar relacionados a um aumento de amônia no sangue 19 , baixas concentrações de glicogênio muscular [20][21] , desidratação 22 e diminuição do pH intramuscular 23 podem diminuir a glicólise e disfunções na neurotransmissão muscular com acúmulo de potássio no músculo 24 . Para a manutenção do equilíbrio corporal, o SNC deve ser informado continuamente sobre o CG, que são reconhecidos por receptores especializados, organizados em sistemas sensoriais específicos [25][26][27] . A fadiga pode diminuir a capacidade de propriocepção a partir de esforços extenuantes, resultando na diminuição de percepção da posição articular 28 .…”