1Neurology Center, Centro Médico American British Cowdray, México, DF, Mexico
2Otorhinolaryngology and Neurotology Department, Instituto Nacional de Neurología y Neurocirugía Dr. Manuel Velasco Suárez, México, DF, Mexico
3Otorhinolaryngology and Neurotology Depaertment, Instituto Nacional de Rehabilitación, México, DF, Mexico