Digital Videokymography: Analysis of Glottal Closure in Adults

INTRODUCTION

High-speed videolaryngoscopy and quantitative analysis of laryngeal images are relevant in accurately diagnosing vocal fold closure patterns.

OBJECTIVE

To analyze the parameters of digital videokymography obtained through high-speed videolaryngoscopy in women and men with complete and incomplete glottal closure, and posterior glottal chink.

METHODS

We conducted an observational, analytical, cross-sectional study with data from 65 adults, which we divided into groups according to sex and glottal closure. Digital videokymography parameters were analyzed using an image-processing program. The Anderson-Darling and Mann-Whitney U tests were used to verify sample normality and compare videokymography parameters between groups, respectively. The significance level was set at 5%.

RESULTS

Among 65 laryngeal images, 20 each were from women with complete and incomplete glottal closure, and 20 and 5 were from men with complete and incomplete glottal closure, respectively. Considering the clinical relevance of the evaluated data, groups of 11 women and 4 men with posterior glottal chink were compared with sex-similar groups with complete glottal closure. Digital videokymography showed a lower maximum and mean vocal fold opening in women with incomplete glottal closure, and a lower dominant left vocal fold-opening amplitude and higher dominant frequency of bilateral vocal fold opening in men with incomplete glottal closure. It also showed a lower closed phase percentage in the posterior region for women and men, with higher closed phase percentage in the anterior and middle regions in women. Both groups with posterior glottal chink showed similar results.

CONCLUSION

Incomplete glottal closure may interfere with the results of the digital videokymography parameters, with higher impact on the posterior vocal fold region in males and the middle and anterior vocal fold regions in females.

Comparison between the acoustic fundamental frequency of the voice and the vibration frequency of the vocal folds analyzed by digital kymography

PURPOSE

To compare the frequency of vocal fold opening variation, analyzed by digital kymography, with the fundamental voice frequency obtained by acoustic analysis, in individuals without laryngeal alteration.

METHODS

Observational analytical cross-sectional study. The participants were forty-eight women and 38 men from 18 to 55 years of age. The evaluation was made by voice acoustic analysis, by the habitual emission of the vowel /a/ for 3 seconds, and days of the week, and digital kymography (DKG), by the habitual emission of the vowels /i/ and /ɛ/. The measurements analyzed were acoustic fundamental frequency (f0), extracted by the Computerized Speech Lab (CSL) program, and dominant frequency of the variation of right (R-freq) and left (L-freq) vocal fold opening, obtained through the KIPS image processing program. The mounting of the kymograms consisted in the manual demarcation of the region by vertical lines delimiting width and horizontal lines separating the posterior, middle and anterior thirds of the Rima glottidis. In the statistical analysis, the Anderson-Darling test was used to verify the normality of the sample. The ANOVA and Tukey tests were performed for the comparison of measurements between the groups. For the comparison of age between the groups, the Mann-Whitney test was used.

RESULTS

There are no differences between the values of the frequency measurement analyzed by digital kymography, with the acoustic fundamental frequency, in individuals without laryngeal alteration.

CONCLUSION

The values of the dominant frequency of the vocal folds opening variation, as assessed by digital kymography, and the acoustic fundamental frequency of the voice are similar, allowing comparison between these measurements in the multidimensional evaluation of the voice, in individuals without laryngeal alteration.

Videokymographic index of glottic function: an analysis of diagnostic accuracy

ABSTRACT Purpose To develop the Videokymographic Index of Glottic Function (VIGF), a composite indicator from digital videokymography parameters, captured by high-speed videolaryngoscopy exams of women with and without laryngeal alterations of behavioral etiology. Methods The sample consisted of 92 women aged between 18 and 45 years. Fifty-five (55) women with behavioral dysphonia, presenting with laryngeal and voice alterations, and thirty-seven (37) women without any laryngeal and voice alterations. Voice evaluation was performed by consensus via an auditory-perceptual analysis of the sustained vowel /a/ at a habitual pitch and loudness. Voice classification was obtained by means of a general degree of dysphonia, where G0 indicated neutral voice quality and G1 to G3 indicated altered voice quality. Laryngeal images were captured via digital videokymography analysis of a sustained vowel /i/ at a habitual pitch and loudness. The VIGF was based on the midpoint of the glottal region for analysis. Logistic regression was performed using the MINITAB 19 program. Results Logistic regression was composed of two stages: Stage 1 consisted of the analysis of all variables, where the maximum opening and closed quotient variables showed statistical significance (p-value <0.05) and the model was well adjusted according to the Hosmer-Lemeshow test (p-value=0.794). Stage 2 consisted of the re-analysis of the selected variables, also showing a well-adjusted model (p-value=0.198). The VIGF was defined as follows: VIGF=e^(8.1318-0.2941AbMax-0.0703FechGlo)/1+e^(8.1318-0.2941AbMax-0.0703FechGlo). Conclusion The VIGF demonstrated a cut-off value equal to 0.71. The probability of success was 81.5%, sensitivity 76.4%, and specificity 89.2%.

Effect of Nebulization on Laryngeal Parameters: Analysis Using High-Speed Digital Videolaryngoscopy

INTRODUCTION

Superficial laryngeal hydration, obtained through nebulization, is related to the moisture level on the epithelial surfaces of the vocal folds, modifying their biomechanical and aerodynamic properties. Through high-speed videolaryngoscopy it is possible to obtain objective data for laryngeal analysis after nebulization and a better understanding of this phenomenon OBJECTIVE: To verify the effects of nebulization with saline solution on laryngeal parameters of digital videokymography obtained by high-speed videolaryngoscopy examination in women and men with and without laryngeal alterations METHOD: This is a clinical, comparative intra-subject study. Fifty-nine adults were selected, with and without laryngeal alterations, 30 females and 29 males. Digital videokymographs in the anterior, middle and posterior thirds of the vocal folds of the participants were analyzed before and after nebulization with 0.9% saline solution.

RESULTS

Women without laryngeal alterations showed more parameters changes after nebulization, in which there was a decrease in maximum and medium opening, amplitude of opening of the left and right vocal fold in the anterior glottal third, and an increase of the percentage of closure of the vocal folds. These results indicate a minor extent of lateral excursion of the vocal folds during phonation. In women with laryngeal alterations, the parameters that changed after nebulization were the increased frequency of opening of the left and right vocal folds in the topography of the posterior third. In men, nebulization did not change the variables studied, except for the amplitude of the right vocal fold in men with laryngeal alterations, in the analysis of the posterior glottic third.

CONCLUSION

The results suggest that surface hydration modifies laryngeal dynamics differently between genders. After nebulization with saline solution, women without laryngeal alterations showed a decrease in the lateralization of the vocal folds during phonation, suggesting a better phonatory efficiency.

Analysis of the Immediate Effects of the LaxVox Technique on Digital Videokymography Parameters in Adults With Voice Complaints

OBJECTIVES

Digital videokymography based on high-speed videoendoscopy enables the evaluation of therapeutic techniques and voice training, such as the LaxVox technique, on vocal fold vibrations. This study investigated the immediate effects of the LaxVox technique on digital videokymographic parameters obtained through high-speed videolaryngoscopy in adults with voice complaints.

STUDY DESIGN

An experimental intrasubject comparative study of adults with voice complaints was conducted.

METHODS

Image processing software was used to analyze the videos and obtain digital videokymography parameters. The intraclass correlation coefficient was used to determine the intra-rater reliability of the analyzed parameters. The paired t test and Wilcoxon signed-rank test were used to compare digital videokymography parameters before and after the LaxVox technique, in sex-specific analyses. The significance level was set at 5%.

RESULTS

In total, 25 laryngeal images from 15 women and 10 men were analyzed. On digital videokymography analysis, the mean vocal fold opening in the posterior glottal region was decreased immediately after using the LaxVox technique in women. In contrast, no significant changes were found in other parameters compared to pre LaxVox technique values in both men and women with voice complaints.

CONCLUSION

Digital videokymography analysis revealed that the LaxVox technique reduces the mean vocal fold opening in the posterior glottal region of women with voice complaints.

Videokymographic index of glottic function: an analysis of diagnostic accuracy

PURPOSE

To develop the Videokymographic Index of Glottic Function (VIGF), a composite indicator from digital videokymography parameters, captured by high-speed videolaryngoscopy exams of women with and without laryngeal alterations of behavioral etiology.

METHODS

The sample consisted of 92 women aged between 18 and 45 years. Fifty-five (55) women with behavioral dysphonia, presenting with laryngeal and voice alterations, and thirty-seven (37) women without any laryngeal and voice alterations. Voice evaluation was performed by consensus via an auditory-perceptual analysis of the sustained vowel /a/ at a habitual pitch and loudness. Voice classification was obtained by means of a general degree of dysphonia, where G0 indicated neutral voice quality and G1 to G3 indicated altered voice quality. Laryngeal images were captured via digital videokymography analysis of a sustained vowel /i/ at a habitual pitch and loudness. The VIGF was based on the midpoint of the glottal region for analysis. Logistic regression was performed using the MINITAB 19 program.

RESULTS

Logistic regression was composed of two stages: Stage 1 consisted of the analysis of all variables, where the maximum opening and closed quotient variables showed statistical significance (p-value <0.05) and the model was well adjusted according to the Hosmer-Lemeshow test (p-value=0.794). Stage 2 consisted of the re-analysis of the selected variables, also showing a well-adjusted model (p-value=0.198). The VIGF was defined as follows: VIGF=e^(8.1318-0.2941AbMax-0.0703FechGlo)/1+e^(8.1318-0.2941AbMax-0.0703FechGlo).

CONCLUSION

The VIGF demonstrated a cut-off value equal to 0.71. The probability of success was 81.5%, sensitivity 76.4%, and specificity 89.2%.

High speed digital videolaringoscopy: evaluation of vocal nodules and cysts in women

PURPOSE

To evaluate and compare the parameters of Digital kymography obtained through the High-speed Videolaryngoscopy of women without laryngeal disorders, of women with vocal fold nodules and of women with vocal cysts.

METHODS

A cross-sectional observational study in which 60 women aged 18 years and 45 years were selected. Three study groups were formed: 20 women without laryngeal disorder forming the control group (Group 1), 20 women with diagnosis of vocal fold nodules forming Group 2 and 20 women with diagnosis of vocal cysts forming Group 3. Subsequently the participants were evaluated by High-speed Videolaryngoscopy for analysis and comparison of laryngeal images using Digital kymography. The laryngeal parameters processed by the program KIPS® were: minimum, maximum and mean opening; dominant amplitude of the left and right vocal folds; dominant frequency of the right and left vocal folds; and close.

RESULTS

The analysis of Digital kymography suggests that the presence of the vocal fold nodules and the vocal cysts tend to restrict more to the maximum and minimum opening of the vocal fold and the dominant amplitude of the opening variation in the middle region of the glottis.

CONCLUSION

Digital kymography parameters were similar in the presence of vocal fold nodules and vocal cysts lesions.

Nebulized Saline Solution: A Multidimensional Voice Analysis

PURPOSE

To verify the effect of nebulization on the voice of dysphonic and non-dysphonic individuals on acoustic, perceptual-auditory, aerodynamic, electroglottographic, laryngeal parameters and on the self-perception of vocal discomfort.

MATERIALS AND METHODS

All the research subjects were submitted to vocal evaluation, laryngeal and voice self-perception. Then, the participants remained in vocal rest for a period of 10 minutes and the analysis mentioned above were again performed. After this first stage, the participants were submitted to the nebulization for a period of 10 minutes and the all analysis above were again performed. Descriptive analysis of the variables was carried. In the comparison of the pre- and post-nebulization groups, the Paired T-Student Test was used for variables with non-dysphonic distribution and the Wilcoxon Test for variables with asymmetric distribution. When categorical variables were evaluated (perceptual-auditory evaluation and laryngeal assessment), the Pearson's Chi-square test was used. In all analysis, a significance level of 5% was considered. The intra-rater agreement in the auditory-perceptual and perceptual-visual assessment was assessed using the AC1 statistic, using the R program. For this purpose, 20% of the voice samples and laryngeal images were replicated blindly and interpreted by the evaluators at the time evaluations.

RESULTS

The results of this research show that non-dysphonic individuals have more positive vocal and laryngeal effects after nebulization than dysphonic ones. It is also observed that the EGG measurement was the most sensitive to the effect of nebulization, with an increase in the Closed quotient (CQ) in all groups evaluated. Regarding acoustic measurements, it is noted that the effect of nebulization in men is more evident than in women. After nebulization, there was an increase in fundamental frequency in the group of non-dysphonic women and dysphonic and non-dysphonic men. A decrease in the amplitude perturbation quotient values is observed in all groups, besides a reduction in the pitch perturbation quotient values after nebulization in non-dysphonic men groups. There was improves aerodynamic efficiency in groups of dysphonic and non-dysphonic men and in the self-perception of vocal discomfort in all groups studied after the hydration procedure. The results of this study demonstrate a significant improvement in the mucosal wave after nebulization in the groups of women and men who are not dysphonic.

CONCLUSION

The nebulization procedure with saline solution improves acoustic measurements, the electroglottographic closed quotient and vocal self-perception of dysphonic and non-dysphonic women and men. Nebulization increases the mucosal wave of the vocal folds in non-dysphonic women and men and improves the aerodynamic efficiency of men.

Multidimensional voice assessment: the immediate effects of Lax Vox® in singers with voice complaints

ABSTRACT Purpose: to multidimensionally assess the effect of the Lax Vox® vocal technique on singers with voice complaints. Methods: a comparative intrasubject study that assessed 30 singers - 13 males and 17 females, aged 18 to 55 years - who self-reported voice complaints and had voice problems symptoms. The participants were submitted to voice assessment with perceptive-auditory, acoustic, aerodynamic, and electroglottographic voice analysis, as well as laryngeal assessment with high-speed videolaryngoscopy. The participants were assessed at two moments: 1) at the beginning of the data collection; and 2) five minutes after performing the Lax Vox® vocal technique. The groups were compared with appropriate statistical tests, with a 5% significance level. Results: in the acoustic analysis, there was an increase in the fundamental frequency for males, after using the Lax Vox® vocal technique. In the aerodynamic assessment, there was an increase in the airflow mean values during vocalization, as well as in aerodynamic power after using the Lax Vox® vocal technique in both groups. Conclusion: the Lax Vox® vocal technique, in the studied singers with a complaint of dysphonia, promoted an increase in the fundamental frequency, for males. In the aerodynamic parameters, in both sexes, it promoted an increase in the airflow and aerodynamic power.

Vestibular Evoked Myogenic Potential on Ocular, Cervical, and Soleus Muscles to Assess the Extent of Neurological Impairment in HTLV-1 Infection

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.

Ocular vestibular evoked myogenic potential (VEMP) reveals mesencephalic HTLV-1-associated neurological disease

Purpose

Vestibular Myogenic Evoked Potential (VEMP) evaluates vestibulo-ocular and vestibulo-collic reflexes involved in the function of the otolithic organs and their afferent pathways. We compared the results of cervical and ocular VEMP in HTLV-1 associated myelopathy (HAM) and HTLV-1-asymptomatic infection.

Participants and methods

This cross-sectional study included 52 HTLV-1-infected individuals (26 HAM and 26 asymptomatic carriers) and 26 seronegative controls. The groups were similar regarding age and gender. Participants underwent simultaneous ocular and cervical VEMP. The stimulus to generate VEMP was a low-frequency tone burst sound tone burst, with an intensity of 120 decibels normalized hearing level, bandpass filter from 10 to 1,500 Hertz (Hz), with 100 stimuli at 500 Hz and 50 milliseconds recording time. The latencies of the electrophysiological waves P13 and N23 for cervical VEMP and N10 and P15 waves for ocular VEMP were compared among the groups. The absence or delay of the electrophysiological waves were considered abnormal results.

Results

Ocular VEMP was similar among the groups for N10 (p = 0.375) and different for P15 (p≤0.001). Cervical VEMP was different for P13 (p = 0.001) and N23 (p = 0.003). About ocular VEMP, in the HTLV-1-asymptomatic group, normal waves were found in 23(88.5%) individuals; in HAM group, normal waves were found in 7(26.9%). About cervical VEMP, 18(69.2%) asymptomatic carriers presented normal waves and only 3(11.5%) patients with HAM presented normal waves. Abnormalities in both VEMPs were found in 1(3.8%) asymptomatic carrier and in 16(61.5%) patients with HAM.

Conclusion

Neurological impairment in HAM was not restricted to the spinal cord. The mesencephalic connections, tested by ocular VEMP, have been also altered. Damage of the oculomotor system, responsible for eye stabilization during head and body movements, may explain why dizziness is such a frequent complaint in HAM.

Ocular and cervical vestibular evoked myogenic potential simultaneous in normal individuals

PURPOSE

To characterize the recording and analyze the results of the combined cervical and ocular vestibular evoked myogenic potential in individuals without hearing and vestibular complaints.

METHODS

In this study, 30 individuals without hearing complaints and hearing within normal limits were evaluated. Data were collected through the simultaneous recording of cervical and ocular vestibular evoked myogenic potential.

RESULTS

Differences were observed between the right and left ears for the amplitude of waves P13 and N23 of the cervical vestibular evoked myogenic potential and the latency of wave N10 of the ocular vestibular evoked myogenic potential. For female subjects, there was no difference between the right and left ears for the amplitude of waves P13, N23, N10, and P15; interamplitude in cervical vestibular evoked myogenic potential and interamplitude in ocular vestibular evoked myogenic potential; and latency in waves P13, N23, N10, and P15. For male subjects, there was a difference between the right and left ears for the amplitude of wave P13.

CONCLUSION

The results of the combined cervical and ocular vestibular evoked myogenic potentials were consistent, because the responses generated by the vestibular evoked myogenic potentials presented an adequate morphology, latency, and amplitude, allowing for the evaluation of the ipsilateral descending vestibular pathways and the contralateral ascending vestibular pathways.

Combined ocular and cervical vestibular evoked myogenic potential in individuals with vestibular hyporeflexia and in patients with Ménière's disease

INTRODUCTION

The vestibular evoked myogenic potential is a potential of mean latency that measures the muscle response to auditory stimulation. This potential can be generated from the contraction of the sternocleidomastoid muscle and also from the contraction of extraocular muscles in response to high-intensity sounds. This study presents a combined or simultaneous technique of cervical and ocular vestibular evoked myogenic potential in individuals with changes in the vestibular system, for use in otoneurologic diagnosis.

OBJECTIVE

To characterize the records and analyze the results of combined cervical and ocular VEMP in individuals with vestibular hyporeflexia and in those with Ménière's disease.

METHODS

The study included 120 subjects: 30 subjects with vestibular hyporeflexia, 30 with Ménière's disease, and 60 individuals with normal hearing. Data collection was performed by simultaneously recording the cervical and ocular vestibular evoked myogenic potential.

RESULTS

There were differences between the study groups (individuals with vestibular hyporeflexia and individuals with Ménière's disease) and the control group for most of wave parameters in combined cervical and ocular vestibular evoked myogenic potential. For cervical vestibular evoked myogenic potential, it was observed that the prolongation of latency of the P13 and N23 waves was the most frequent finding in the group with vestibular hyporeflexia and in the group with Ménière's disease. For ocular vestibular evoked myogenic potential, prolonged latency of N10 and P15 waves was the most frequent finding in the study groups.

CONCLUSION

Combined cervical and ocular vestibular evoked myogenic potential presented relevant results for individuals with vestibular hyporeflexia and for those with Ménière's disease. There were differences between the study groups and the control group for most of the wave parameters in combined cervical and ocular vestibular evoked myogenic potential.

Graphic angle measure as an electrocochleography evaluation parameter

To improve electrocochleography's diagnostic sensitivity in Meniére's disease - new assessment methods are being studied.

Aim

To determine whether or not graphic angle measurement is sensitive and specific to Menière's disease laboratorial diagnosis and if there is an increase in the electrocochleography's sensitivity and specificity when graphic angle measurements are associated with Summating Potential-Action Potential ratio (SP/AP ratio).

Methods

Electrocochleography's was used to analyze 71 ears from 55 subjects: 41 patients with clinical diagnosis of Menière's disease (MD group), and 14 healthy individuals as control (Group C). Graphic results were analyzed initially to obtain the SP/AP ratio; afterwards, through another program graphic angle measurements were calculated.

Results

Sensitivity and specificity values of angle measures, SP/AP ratio, and the association between them varied according to the cutoff point, the highest equilibrium between sensitivity and specificity was observed with the values of 166.25 for angle measurement and 27% for SP/AP relation; 62.79% / 60.71% and 74.42% / 67.86%, respectively. The association between measurements showed a sensitivity increase due to the specificity decrease; 88.37% and 50%, respectively.

Conclusion

Angle graphic measurement is not sensitive and specific enough for the laboratorial diagnosis of MD. Angle graphic measurement and SP/AP ratio association proved to be higher in sensitivity, in detriment of exam specificity.

Avaliação laríngea e vocal de pacientes com bulimia

Bulimia is an eating disorder classified as a mental disorder according to DSM-IV.

Aims

The aim of the study was to evaluate vocal and laryngeal abnormalities in patients with bulimia compared to a control group.

Materials & methods

Study control group. Twenty-two women were evaluated, with an age range of 18 to 34 years old. Eleven diagnosed with purging bulimia and 11 in the control group. Both groups underwent an otolaryngological, perception and acoustic evaluation. The statistic analysis was done through a chi-square test and a Kruskall-Wallis non-parametric test, considering 5% as significance level.

Results

The bulimic group presented a higher prevalence of laryngeal abnormalities compared to the control group (p=0.000). The group with bulimia had higher GRBSI values (p=0.000) and A (p=0.022) of the GRBASI scale. The results of vocal acoustics analysis of the jitter, shimmer, PPQ and APQ were higher in the bulimic group (p=0.033). No statistical significance difference in the fundamental frequency and NHR were found between both groups.

Conclusion

the bulimic patients in this study presented more laryngeal, acoustics and perception evaluation disorders when compared to a control group.

[Vestibular evoked myogenic potential findings on multiple sclerosis]

INTRODUCTION

Vestibular evoked myogenic potential (VEMP) elicited by acoustic stimulation, has been proposed in the assessment of vestibulospinal pathways.

AIM

To research the clinical utility of VEMP on multiple sclerosis (MS).

SUBJECTS AND METHODS

Forty-four individuals were evaluated (30 normal state and 14 had MS). The acoustic stimuli were short tone burst (1 kHz, 118 dBNa, rise-fall 1 ms, plateau 2 ms) presented through a supra-aural earphone. The stimulation rate was 5 stimuli per second.

RESULTS

All the healthy subjects showed a normal VEMP response. In the MS group, abnormal VEMP was recorded among 92.8% of patients and normal in just one case. The P13-N23 increased of prolongation which was the most frequently alteration (57.1%), followed by absence of response among four (28.5%) cases.

CONCLUSION

VEMP was considered a good method of diagnostic support of vestibulospinal tract in cases of MS.

Potencial evocado miogênico vestibular (Vemp): avaliação das respostas em indivíduos normais

TEMA: o Potencial Evocado Miogênico Vestibular (Vemp) é formado por respostas miogênicas ativadas por estimulação sonora de alta intensidade. Essas respostas são registradas por eletromiografia de superfície sobre a musculatura cervical na presença de contração muscular, ativando a mácula, o nervo vestibular inferior e as vias vestíbulo-espinhais descendentes. OBJETIVO: descrever as respostas evocadas do Vemp em uma população normal. MÉTODO: selecionaram-se 30 sujeitos adultos, sendo 13 homens e 17 mulheres, sem queixas otoneurológicas. Utilizou-se 200 estímulos tone burst com freqüência de 1Hz e intensidade de 118dB Na, filtro passa-banda de 10Hz a 1500Hz. Os traçados obtidos foram analisados em relação ao primeiro potencial bifásico composto por P13 e N23. RESULTADOS: não houve diferença estatisticamente significativa entre o lado da estimulação em relação a latência e amplitude, porém foi encontrada diferença estatisticamente significativa em relação à amplitude do potencial entre os sexos. CONCLUSÃO: Vemp demonstrou ser uma ferramenta confiável na avaliação da função vestibular.

Mismatch negativity contribution in multiple sclerosis patients

Mismatch Negativity is a functional index of the supratemporal auditory cortex.

AIM

The aim of the present study on Mismatch Negativity (MMN) in multiple sclerosis (MS) patients was to evaluate if the MMN can be correlated with cognitive deficits assessed by the Paced Auditory Addition Task--PASAT.

METHOD

a clinical study in forty females and 20 males separated in two groups: control individuals and those with a definite diagnosis of MS underwent a duration and frequency MMN. The MMN latencies and negative amplitudes obtained from the MS group were compared to the ones from the control group. The scores from the Paced Auditory Addition Task were correlated either with the presence or the absence of MMN.

RESULTS

MMN was found in 60% of the individuals with multiple sclerosis within the auditory stimulation protocol with varied durations, and in 45 % within the auditory stimulation protocol with frequency variations. There were no statistically significant differences in latencies and amplitudes when compared to controls. We found a statistically significant correlation for the lack of MMN wave together with cognitive disorder asserted by the PASAT.

CONCLUSIONS

The MMN correlated to the cognitive deficit assessed by the PASAT.

Contribuição do Mismatch Negativity na avaliação cognitiva de indivíduos portadores de esclerose múltipla

O Mismatch Negativity (MMN) é um potencial evocado auditivo endógeno, gerado por mudanças no processo de discriminação que ocorrem no córtex auditivo que avalia a memória sensorial auditiva. OBJETIVOS: Avaliar se, quando presente, o MMN pode ser utilizado como um índice funcional do córtex auditivo supratemporal e correlacionar com comprometimento cognitivo, avaliado pelo Teste Auditivo Compassado de Adição Seriada (PASAT). MATERIAL E MÉTODOS: Um grupo controle e outro com diagnóstico definido de EM foram submetidos ao registro do MMN com estímulos auditivos com variação de duração e de freqüência. O grupo de EM foi submetido ao PASAT. As latências e as amplitudes negativas do MMN foram comparadas entre os grupos. Os escores do PASAT foram correlacionados com a presença ou ausência do MMN nos dois protocolos de estimulação auditiva. RESULTADOS: O MMN esteve presente em 60% dos indivíduos no grupo de EM no protocolo de estimulação auditiva com variação de duração, e em 45% no protocolo de estimulação auditiva com variação de freqüência. Encontrou-se uma correlação estatisticamente significante entre a ausência da onda do MMN com a presença de comprometimento cognitivo avaliado pelo PASAT. CONCLUSÕES: A ausência do MMN se correlaciona com comprometimento cognitivo avaliado pelo PASAT.

Determination of radial artery compliance can increase the diagnostic power of pulse wave velocity measurement

Pulse wave velocity (PWV) is an indicator associated with the arterial stiffness. Although this technique has been used in the diagnosis of systemic arterial hypertension (SAH), it cannot supply alone enough information about the pathogenesis of this disturbance. This paper aims to determine the compliance of brachial-radial arterial segment by applying a three-element windkessel model, and by using the same pressure waveforms acquired to calculate the PWV. The proposed method to determine the arterial compliance was evaluated with a physical simulation of the arterial system, where parameters were known, resulting in an estimation error of 0.73 x 10(-7) cm5 dyne(-1). In a clinical study the estimated compliance was statistically different (p < 0.01) in a controlled group ((3.12 +/- 3.53) x 10(-7) cm5 dyne(-1)) and in an SAH group ((1.04 +/- 0.74) x 10(-7) cm5 dyne(-1)). It was observed that the PWV value calculated using the maximum of the first derivative of the pressure waveform upstroke as characteristic points was the best correlated (r = -0.71) with the determined compliance. Because SAH normally results, among other causes. from a decreased arterial compliance the results suggest that the determined compliance could be used concomitantly with PWV to supply more diagnostic information about the pathogenesis of SAH.

[Auditory evoked potentials evaluation of the brain stem in multiple sclerosis]

The aim of this study was to evaluate the incidence of auditory and neurotological disorders in multiple sclerosis (MS). Twenty female and 9 male with a definite diagnosis of multiple sclerosis without signs of involvement of the brain stem underwent an audiological and an early auditory evoked potentials (EAEP). The wave forms were classified according to Jerger's (1986) classification. In 58 EAEP it was found 55% of type I (normal response) according to Jerger's classification in both sexes. Considering as an abnormal response the EAEP classified in type II, III, IV or V according to Jerger in at least one side, it was found 60% of abnormalities in females and 56% in males, totalizing 58,62% of all the studied subjects. The authors emphasize the use of EAEP in MS.