Hipoacusia neurosensorial adquirida asociada a alteraciones vestibulares y / o control postural / Neurosensorial acquired hypoacusia associated with vestibular alterations and / or postural control

La otitis media aguda es una infección del oído medio con alta prevalencia en población pediátrica, las complicaciones pueden generar desde hipoacusia neurosensorial de diverso grado hasta alteración vestibular y/o control postural, aunque de ello no existen mayores reportes ni investigaciones en Chile. Por lo anterior, el objetivo fue asociar la hipoacusia neurosensorial a alteraciones vestibulares y/o de control postural. Se evaluó a un sujeto de sexo femenino, 13 años de edad, quien presentó múltiples cuadros de Otitis Media Aguda y fue diagnosticada con hipoacusia neurosensorial bilateral grado moderado. Antes del estudio, reportó desequilibrio y aumento de riesgo de caída. Se aplicaron test auditivos (timpanometría y audiometría), vestibulares (evaluación del VIII par craneal) y de control postural (posturógrafo y tests "Time up and go", Romberg y Romberg en tándem). Se encontraron alteradas la prueba de integración sensorial, con predominancia del hemicuerpo derecho, igualmente predominancia a alteraciones auditivas en el oído derecho ante pruebas que valoraron oído medio. Se observó una relación directa entre las alteraciones posturales y de equilibrio con el tipo y grado de pérdida auditiva que presenta el sujeto de estudio.

The acute otitis media is a middle ear infection with high prevalence in pediatric population, the complications could generate from sensorineural hearing loss to vestibular alteration and/or postural control, although, there aren´t report or researches of it in Chile. Therefore, the objective was to associate sensorineural hearing loss with vestibular alterations and/or postural control. We evaluated a female subject presenting multiple events of acute otitis media and she was diagnosed with sensorineural hearing loss middle grade. Before this study, she reported imbalance and falling risk. Hearing (tympanometry and audiometry), vestibular (evaluation of the VIII cranial nerve) and postural control tests were applied (posturography and "Time up and go", Romberg and Romberg in tandem test). It was found altered the integration sensorial test, with predominance to half body right and predominance of hearing impairment in the right ear to the middle ear evaluated evidence. It was observed a direct relation between postural alterations and balance with the hearing loss type from the subject of study.

Galvanic vestibular stimulator for fMRI studies

INTRODUCTION: Areas of the brain that are associated with the vestibular system can be activated using galvanic vestibular stimulation. These areas can be studied through a combination of galvanic vestibular stimulation with functional magnetic resonance imaging (fMRI). In order to provide an appropriate sequence of galvanic stimulation synchronous with the MRI pulse sequence, a specific electronic device that was built and assessed is presented. METHODS: The electronic project of the GVS is divided in analog and digital circuits. The analog circuits are mounted in an aluminum case, supplied by sealed batteries, and goes inside the MRI room near to the feet of the subject. The digital circuits are placed in the MRI control room. Those circuits communicate through each other by an optical fiber. Tests to verify the GVS-MRI compatibility were conducted. Silicone (in-house) and Ag/AgCl (commercial) electrodes were evaluated for maximum balance and minimal pain sensations. fMRI experiments were conducted in eight human volunteers. RESULTS: GVS-MRI compatibility experiments demonstrate that the GVS did not interfere with the MRI scanner functionality and vice versa. The circular silicone electrode was considered the most suitable to apply the galvanic vestibular stimulation. The 1 Hz stimulation sinusoid frequency produced the biggest balance and the less pain sensations when compared to 2 Hz. The GVS was capable of eliciting activation in the precentral and postcentral gyri, in the central sulcus, in the supplementary motor area, in the middle and inferior frontal gyri, in the inferior parietal lobule, in the insula, in the superior temporal gyrus, in the middle cingulate cortex, and in the cerebellum. CONCLUSION: This study shows the development and description of a neurovestibular stimulator that can be safely used inside the MRI scanner room without interfering on its operation and vice versa. The developed GVS could successfully activate the major areas involved with multimodal functions of the vestibular system, demonstrating its validity as a stimulator for neurovestibular research. To the best of our knowledge, this is the first work that shows the development and the construction of a galvanic vestibular stimulator that could be safely used inside the MRI room.

Controle postural e sistema vestíbulo-oculomotor em atletas de tiro esportivo da modalidade pistola / Posture control and vestibular oculomotor system in pistol sport shooters

INTRODUÇÃO: O tiro esportivo desenvolve nos atletas destreza, concentração e equilíbrio. A estabilidade do atirador depende da resistência deste contra perturbações internas e externas que afetem seu equilíbrio. OBJETIVO: Avaliar o controle postural e sistema vestíbulo-oculomotor de atletas atiradores de pistola. MÉTODO: Análise descritiva do tipo transversal. Avaliaram-se oito atletas com idade média de 37 anos (dp ± 8,11), afiliados à Confederação Brasileira de Tiro Esportivo. Utilizou-se prontuário sociodemográfico; estabilometria associada a simulador de tiro e sistema de videonistagmoscopia computadorizada. RESULTADOS: Observou-se em todos os voluntários, dominância motora à direita; metade deles atira com os dois olhos abertos; tempo médio de prática de 14 anos (dp ± 9) e média de treino semanal de 14 horas (dp ± 13). Metade relatou lesão associada ao tiro. Na estabilometria observou-se correlação nas velocidades anteroposterior e mediolateral.À videonistagmoscopia, nenhum atleta apresentou alteração patológica. CONCLUSÃO: O controle postural dos atletas avaliados possui alterações significativas para as velocidades de deslocamento do centro de pressão nas direções anteroposterior e mediolateral. O sistema vestíbulo-oculomotor não mostrou correlação com o controle postural e se apresentou sem alterações funcionais para todos os voluntários.

INTRODUCTION: Shooting sports develop dexterity, concentration and balance in the athletes. The stability of the shooter is dependent on his/her resistance against internal and external disturbance that affects his/her balance. OBJECTIVE: To evaluate the posture control and vestibular-oculomotor system of athletic pistol shooters. METHODS: A cross-sectional descriptive analysis. Eight subjects (mean age of 37 years; SD ± 8.11), affiliated to the Brazilian Shooting Confederation were evaluated. A sociodemographic questionnaire, besides stabilometry associated with the shooting simulator and videonistagmoscopic computerized system were used. RESULTS: All volunteers presented right motor dominance; half shot with both eyes open; average practice time is 14 years (SD ± 9) and weekly training average is of 14 hours (SD ± 13). Half athletes reported injuries associated with shooting. Stabilometric correlation presented correlation in the anteroposterior and mediolateral velocities. None of the athletes presented pathological alteration in the videonistagmoscopic evaluation. CONCLUSION: Posture control of the assessed athletes presents significant changes to the displacement of the center of pressure velocities in the anterior-posterior and medial-lateral directions. The vestibulo-ocular system was not correlated with posture control and functional changes were not observed in any of the volunteers.