Avaliação do efeito da idade sobre a função vestibular por meio do Teste do Impulso Cefálico (v-HIT)

Abstract

Purpose: to evaluate the effect of age on vestibular-ocular reflex gain through v-HIT. Methods: this was a cross-sectional, analytical, observational study conducted with 90 subjects without self-reported otoneurological alterations, who underwent v-HIT examination in order to evaluate semicircular canal gain and cephalic pulse velocity. Results: the age of the sample ranged from 20 to 83 years. It was decided that the sample be divided into three age groups to facilitate the analysis: 18 to 30 years; 31 to 59 years, and over 60 years old. A decrease in vestibular-ocular reflex gains of the right and posterior semicircular canals was observed with increasing age. The average semicircular canal gain was close to one and the velocities above 100º/s. Conclusion: the average gain of the semicircular canals is within the normality standards found in the literature. Only the posterior and right anterior semicircular canals showed reduced gain with increasing age. RESUMO Objetivo: avaliar o efeito da idade sobre o ganho do reflexo vestíbulo-ocular por meio do v-HIT. Métodos: estudo transversal, analítico, observacional, realizado com 90 indivíduos sem alterações otoneurológicas autorrelatadas, que foram submetidos ao exame v-HIT, com o intuito de avaliar o ganho dos canais semicirculares e a velocidade dos impulsos cefálicos. Resultados: a idade da amostra variou de 20 a 83 anos. Optou-se pela divisão em três faixas etárias para facilitar a análise: 18 a 30 anos; 31 a 59 anos e maior que 60 anos. Houve diminuição dos ganhos do reflexo vestíbulo-ocular dos canais semicirculares anterior direito e posteriores com o aumento da idade. As médias do ganho dos canais semicirculares foram próximas a 1 e as velocidades, acima de 100º/s. Conclusão: as médias do ganho dos canais semicirculares estiveram de acordo com os padrões de normalidade da literatura. Apenas os canais semicirculares posteriores e o anterior direito apresentaram redução do ganho com o aumento da idade.

Video head impulse test (v-hit) em indivíduos com diabetes mellitus tipo 1

“…The female gender, even being prevalent in both groups, showed only association with the right posterior canal in the group without diabetes. The group without diabetes showed values within the normal range of gain in all SC, as expected for individuals without vestibular disease (17)(18)(19)(20)(21)(22) .…”

“…Several studies have highlighted the practicality and objectivity of v-HIT, which is able to accurately locate the affected semicircular canal, confirming the clinical usefulness of this exam in the diagnosis and monitoring of the individuals with otoneurological disorders rehabilitation (17)(18)(19)(22)(23)(24) .…”

“…Although in the group with DM1, lower velocities have been applied for stimulation of the left lateral, right anterior and left posterior SC, in comparison with the control group, for all SC, in both groups, adequate velocity was applied, as recommended in the literature and in the equipment manual for reliable examination -above 120°/s for the lateral canals and 100°/s for the vertical canals (21)(22)(23)(24) . In addition, for these SC, there was no statistical correlation between the velocity and the value of the VOR gain.…”

“…The VOR is responsible for maintaining a clear image on the retina during head movements, triggering compensatory eye movements in the opposite direction (20,21) . Previous studies used the caloric test to assess the vestibular function of individuals with diabetes mellitus, but, currently, this analysis can be performed in an objective and detailed way, through the assessment of the vestibulo-ocular reflex using the Video Head Impulse Test (v -HIT) (22)(23)(24)(25) .…”

“…With each impulse, v-HIT records the head movements and the reflex response of the eye. Impulsive tests are fast in triggering VOR without cortical contamination or slow eye systems, assessing the vestibular function at higher frequencies than caloric testing (22)(23)(24) .…”