RESUMEN
Introduction: Vestibular Evoked Myogenic Potential (VEMP) can be used to test central vestibular pathways from the midbrain to the lumbar spine, according to the muscle tested. Purpose: to compare the spinal cord alteration in individuals with HTLV-1-associated myelopathy (HAM) and with HTLV-1-asymptomatic infection using the VEMP recorded from different muscles. Methods: VEMP was recorded in 90 individuals of whom 30 had HAM, 30 were HTLV-1 asymptomatic carriers, and 30 negative controls. VEMP was recorded in the oculomotor muscle (oVEMP), testing the vestibulo-ocular reflex, and in the cervical muscle (cVEMP) and soleus muscle (sVEMP), testing the vestibulospinal reflex, respectively, in the cervical and in the lumbar spinal level. The type of stimulation was auditory for oVEMP and cVEMP, and galvanic for sVEMP. The compared variables were the latencies of the electrophysiological waves. Results: HTLV-1-asymptomatic group was similar to the controls regarding oVEMP (p = 0.461), but different regarding cVEMP (p < 0.001) and sVEMP (p < 0.001). HAM group has presented the worst latencies and was different from the HTLV-1-asymptomatic group in the VEMP of all the tested muscles (p < 0.001). The concomitant occurrence of VEMP alterations in the three recorded muscles of the same individual was found in 2 (6.7%) asymptomatic carriers and in 20 (66.7%) patients with HAM (p = 0.001). The analysis of VEMP alteration per group and per muscle has showed that, in HTLV-1-asymptomatic group, oVEMP was altered in 3 (10.0%) individuals, cVEMP in 10 (33.3%) and sVEMP in 13 (43.3%). In HAM group, oVEMP was altered in 23 (76.6%) individuals, cVEMP in 27 (90%), and sVEMP in 30 (100%). Conclusion: HTLV-1-neurological damage has followed an ascendant progression beginning at the lumbar spine in the stage of a clinically asymptomatic infection, whereas HAM has affected not only the spine, but also the midbrain.
RESUMEN
OBJECTIVES: To analyze the discrimination ability of acoustic, auditory parameters, and perception of vocal effort during professional and social voice use, and the correlations of these parameters with the vocal demands. STUDY DESIGN: Longitudinal study. METHODS: Seventy-three subjects participated in the study: 31 females aged from 28 to 65 years (G1; professional voice users) and 42 females aged from 31 to 59 years (G2, social voice users; ). All the subjects were subjected to acoustic voice analysis including F0 median, semiamplitude interquartile, quantile 99.5%, and skewness; first F0 derivate mean, standard deviation (SD), and skewness; intensity skewness; spectral slope mean, SD, and skewness; long-term average spectrum-frequency SD, perceptual parameters (GRBASI scale), and self-perception of vocal effort, before and after 2 hours and 30 minutes of voice use. Statistical analyses were completed via multivariate discriminant analysis and canonical correlation analysis. RESULTS: Discriminant analysis of acoustic, perceptual, and self-rating variables and analysis of the grouped parameters did not differentiate the samples before and after vocal use. Higher levels of canonical correlation were found for the professional voice group after voice use, with a correlation between perceptual analysis and acoustic measures. CONCLUSIONS: The current measures could not discriminate the differences of the type of vocal demands, professional or social.