Electrococleografía extratimpánica en una población normal. Estudio descriptivo / Extra-tympanic electrocochleography in a normal population. A descriptive study

Introducción y objetivos: La electrococleografía extratimpánica es un registro elecrofisiológico que refleja la actividad eléctrica acontecida en la cóclea tras un estímulo sonoro. Se obtiene mediante la aplicación del estímulo en el conducto auditivo externo y el registro de la actividad eléctrica mediante electrodos de superficie. Dada la escasa literatura existente acerca de la exploración electrococleográfica normal en nuestro medio, este estudio busca regularizar los valores obtenidos mediante esta exploración en sujetos sin enfermedad otoneurológica y explicar detalladamente el proceso mediante el cual se obtiene el registro. Métodos: Exploración mediante electrococleografía extratimpánica de 60 oídos sin enfermedad otoneurológica y análisis estadístico de los resultados obtenidos. De ellos, 30 oídos fueron explorados a 90dB mientras que otros 30 oídos fueron estimulados a 80dB. Resultados: Se muestran los valores medios de amplitud y latencia del potencial de sumación y del potencial de acción, así como las latencias medias de la onda I y la onda II. Asimismo, se presenta el cálculo del cociente potencial de sumación/potencial de acción. Obtenidos estos resultados se comparan en función de la intensidad del estímulo, del sexo del paciente, del oído estudiado y del grupo etario. Conclusiones: Este estudio recopila datos sobre la electrococleografía en una población normal. Los valores obtenidos están en el rango de los valores normales de otros países, expuestos en la literatura internacional. Estos datos pueden ser muy útiles como referencia a la hora de valorar exploraciones en pacientes con dolencias que afectan la estructura o la función coclear (AU)

Introduction and objectives: Extra-tympanic electrocochleography is an electrophysiological register obtained after stimulating the cochlea with an audible stimulus. This stimulus is applied using an earphone over the external auditory canal, while the electrical activity is registered by surface electrodes. There are few studies that analyse normal electrocochleography in our environment. Thus, the main objective of our study was to regularize the values obtained with electrocochleography in ears without any otoneurological diseases. We explain in detail the process of obtaining the register. Methods: Sixty healthy ears were studied by extratympanic electrocochleography. Statistical results were analysed. While 30 ears were studied with a stimulus at 90dB, another 30 ears were studied with a stimulus at 80dB. Results: Summating potential and action potential latencies and amplitudes were measured. Summating potential/action potential ratios were calculated. Wave I and wave II latencies were also determined. These results were analysed in function of stimulus intensity, patient gender, patient age group and ear side studied. Conclusions: This study collected extra-tympanic electrocochleography data in a normal population and the results were in the range of other international studies obtained in other countries. These data can be used as a reference to evaluate illnesses that affect cochlear structure or functions (AU)

Extra-tympanic electrocochleography in a normal population. A descriptive study. / Electrococleografía extratimpánica en una población normal. Estudio descriptivo.

INTRODUCTION AND OBJECTIVES: Extra-tympanic electrocochleography is an electrophysiological register obtained after stimulating the cochlea with an audible stimulus. This stimulus is applied using an earphone over the external auditory canal, while the electrical activity is registered by surface electrodes. There are few studies that analyse normal electrocochleography in our environment. Thus, the main objective of our study was to regularize the values obtained with electrocochleography in ears without any otoneurological diseases. We explain in detail the process of obtaining the register. METHODS: Sixty healthy ears were studied by extratympanic electrocochleography. Statistical results were analysed. While 30 ears were studied with a stimulus at 90dB, another 30 ears were studied with a stimulus at 80dB. RESULTS: Summating potential and action potential latencies and amplitudes were measured. Summating potential/action potential ratios were calculated. Wave I and wave II latencies were also determined. These results were analysed in function of stimulus intensity, patient gender, patient age group and ear side studied. CONCLUSIONS: This study collected extra-tympanic electrocochleography data in a normal population and the results were in the range of other international studies obtained in other countries. These data can be used as a reference to evaluate illnesses that affect cochlear structure or functions.