ABSTRACT
RESUMEN Los sistemas vestibular, visual y somatosensorial coordinan el control postural y se adaptan a las actividades cotidianas en diferentes contextos, sin embargo, cuando existe un cuadro clínico con sintomatología vestibular, las ponderaciones de estos sistemas cambian mayoritariamente al sistema visual, creando una dependencia visual. El cerebelo, que es el principal encargado de generar una compensación vestibular en casos de hipofunción vestibular, juega un rol destacado en el aprendizaje motor generando comportamientos adaptativos que se transforman en puntos claves en la rehabilitación vestibular. Este artículo pretende exponer lo que la literatura informa en relación a la dependencia visual en pacientes con hipofunción vestibular.
ABSTRACT The vestibular, visual and somatosensory systems coordinate postural control and adapt to daily activities in different contexts, however, when there is a clinical picture with vestibular symptoms, the weights of these systems change mainly to the visual system, creating a visual dependence. The cerebellum, which is the main responsible for generating vestibular compensation in cases of vestibular hypofunction, plays a prominent role in motor learning generating adaptive behaviors that become key points in vestibular rehabilitation. This article aims to expose what the literature reports in relation to visual dependence in patients with vestibular hypofunction.
Subject(s)
Humans , Visual Perception/physiology , Vestibular Diseases/physiopathology , Vestibular Diseases/rehabilitation , Vestibular Diseases/diagnosis , Vertigo , Motion Sickness , Postural Balance , NeurotologyABSTRACT
BACKGROUND AND OBJECTIVES: Vestibular function tests are very useful in diagnosing dizzy patients. Among them, bithermal caloric test is most commonly used test for localizing their permanent vestibular loss. However, it causes much discomfort to the patients with non-physiologic stimuli. In addition, it doesn't represent the present functional status of vestibular system. Therefore, normal caloric result does not accurately correspond to normal vestibular function in dizzy patients. Currently, rotation chair test and dynamic posturography have been introduced adjunctly to assess vestibular function accompanied by bithermal caloric test. It has not been elucidated for their specific role in diverse settings of vestibular disorders. So we planned this study to evaluate clinical usefulness of rotation chair test, videonystagmography and computerized dynamic posturogr-phy in dizzy patients with normal caloric response. MATERIALS AND METHODS: We reviewed clinical records of 46 patients who met their inclusion criteria. They were categorized into five subgroups according to abnormal vestibular function test findings. RESULTS: In each subgroup, we hypothesized its clinical relevance, possible mechanism of dizz-iness and presumed diagnosis. Five categories are as below; visual dependency, imbalance of vestibular tones, chronic peripheral vestibulopathy, abnormality in the vestibulospinal tract and abnormality of oculomotor system. CONCLUSION: We suggest new classification of abnormal vestibular functional status in dizzy patients with normal caloric results. These are comparable according their clinical features and thought to be helpful in managing and counseling each patient.