A influência da oculomotricidade e do reflexo-vestíbulo-ocular na leitura e escrita / The influence of eye movement and the vestibular-ocular reflex in reading and writing

OBJETIVO: verificar se alterações na oculomotricidade e no reflexo vestíbulo-ocular estão relacionados com a dificuldade de leitura e escrita. MÉTODOS : foram selecionados 18 sujeitos de ambos os gêneros, faixa etária entre nove e 14 anos de idade, com audição e acuidade visual estática dentro dos padrões de normalidade, sendo um grupo de 11 sujeitos com dificuldade de leitura e escrita e outro grupo controle composto por sete sujeitos sem a dificuldade. Os exames realizados foram avaliações da linguagem escrita, acuidade visual estática, acuidade visual dinâmica, audiológica e oculomotricidade. RESULTADOS : a acuidade visual estática, calibração, nistagmo espontâneo e semi - espontâneo apresentaram-se dentro da normalidade em toda população estudada. As provas de acuidade visual dinâmica e movimento sacádico apresentaram diferença estatisticamente significante (p<0,05) entre os grupos estudados, enquanto o movimento de rastreio apresentou alterações em ambos os grupos, não ocorrendo diferença estatística. CONCLUSÃO: alterações na oculomotricidade, assim como mal desempenho do reflexo vestíbulo-ocular mostrado na acuidade visual dinâmica podem estar interferindo na dificuldade do desenvolvimento da leitura e escrita. .

PURPOSE: to determine whether changes in eye movement and vestibular- ocular reflex are related to the difficulty of reading and writing. METHODS: 18 subjects of both genders, aged between nine and 14 years of age with hearing and static visual acuity within normal limits were selected: one group of 11 subjects with reading and writing and other composite control group seven subjects without difficulty. The tests included evaluations of written language, static and dynamic visual acuity, audiological and eye movements. RESULTS: static visual acuity, calibration, spontaneous and semi- spontaneous nystagmus were within the normal range throughout the study population. Proofs of dynamic visual acuity and saccades showed statistically significant difference (p < 0.05) between the groups, while the smooth-persuit eye movements showed changes in both groups, with no statistical difference. CONCLUSION: alterations in eye movement, as well as poor performance of the vestibulo-ocular reflex shown in dynamic visual acuity may be interfering with the difficulty of the development of reading and writing. .

Amplitude modulated vestibular evoked myogenic responses: a study of carrier and modulating frequencies.

CONCLUSION: Responses with greater amplitude were recorded when carrier frequencies were modulated at 37, 40, and 43 Hz. These responses can be recorded even in patients with significant sensorineural hearing loss, from the sternocleidomastoid (SCM) muscle for a 500 Hz tone, 100% modulated at 40 Hz. OBJECTIVE: To determine the best carrier and modulating frequencies to evoke steady-state myogenic responses. METHODS: The present study investigated 156 ears of 78 normal-hearing young adults, with carrier frequencies of 250, 500, and 1000 Hz, modulated at 20, 37, 40, 43, 70, 77, and 80 Hz, with an intensity of 95 dBA. Furthermore, we observed responses evoked by stimulus carrier frequency of 500 Hz, modulated at 40 Hz, with an intensity of 95 dBA in a group of five subjects with severe sensorineural loss. RESULTS: Responses were found for all stimuli studied (p < 0.01). Modulated stimuli at frequencies of 37, 40, and 43 Hz evoked better steady-state vestibular evoked myogenic potential (S-VEMP) (p < 0.05). No statistically significant differences were found between the group of normal hearers and the group of subjects with hearing loss (p = 0.431), for the stimulus used.

A pilot study on the evaluation of postural strategies in young and elderly subjects using a tridimensional electromagnetic system.

UNLABELLED: One resorts to various postural strategies while attempting to maintain balance. OBJECTIVE: To assess the postural strategies adopted by young and elderly subjects in varying sensory conditions by using a system of tridimensional electromagnetic sensors positioned on the projection of the first thoracic vertebra and on the sacral region. Postural oscillation values for young and elderly subjects were also reported. METHOD: This observational cross-sectional study enrolled 25 young and 16 elderly individuals. A Polhemus™ device equipped with two sensors was used to assess postural oscillation parameters (maximum displacement, mean velocity, and trajectory). Data acquisition was carried out with subjects standing while undergoing a 90-second test in four sensory conditions: eyes opened, eyes closed, on a stable surface, and on an unstable surface. RESULTS: Sensors 1 and 2 presented significant cross-correlations in all sensory conditions for both groups (r > 0.99; p < 0.001). No statistically significant differences were seen when the cross-correlations for both groups were compared. CONCLUSION: This study presented an important tool to analyze postural oscillation and assess the postural strategies of young and elderly subjects in different sensory conditions. Young and elderly individuals presented strong correlations between sensors (ankle strategy), but no statistically significant differences were seen between groups.

Um estudo piloto na avaliação das estratégias posturais em jovens e idosos usando um sistema eletromagnético tridimensional / A pilot study on the evaluation of postural strategies in young and elderly subjects using a tridimensional electromagnetic system

Para manter o equilíbrio postural, algumas estratégias posturais são normalmente usadas. OBJETIVO: Avaliar as estratégias posturais de jovens e idosos em diferentes condições sensoriais usando um sistema de sensores eletromagnéticos tridimensionais posicionados na primeira vértebra torácica e região sacral. Também reportamos valores de oscilação postural dos jovens e idosos. MÉTODO: Estudo transversal observacional. Participaram do estudo 25 jovens e 16 idosas. O equipamento PolhemusTM com dois sensores foi usado para avaliar os parâmetros de oscilação postural (deslocamento máximo, velocidade média e trajetória). A aquisição dos dados foi realizada com os sujeitos em pé, realizando um teste de 90 segundos para as quatro condições sensoriais: olhos abertos e fechados nas superfícies estável e instável. RESULTADOS: Os sensores 1 e 2 apresentaram alta correlação cruzada em todas as condições sensoriais para ambos os grupos (r > 0.99; p < 0.001). Comparando a correlação cruzada entre os grupos, não foram observadas diferenças significativas. CONCLUSÃO: Este estudo apresentou uma importante ferramenta na análise de oscilação postural e na avaliação das estratégias posturais de jovens e idosos em diferentes condições sensoriais. Os jovens e idosos apresentaram uma forte correlação entre os sensores (estratégia do tornozelo), porém, não foram observadas diferenças significativas entre os grupos.

One resorts to various postural strategies while attempting to maintain balance. OBJECTIVE: To assess the postural strategies adopted by young and elderly subjects in varying sensory conditions by using a system of tridimensional electromagnetic sensors positioned on the projection of the first thoracic vertebra and on the sacral region. Postural oscillation values for young and elderly subjects were also reported. METHOD: This observational cross-sectional study enrolled 25 young and 16 elderly individuals. A PolhemusTM device equipped with two sensors was used to assess postural oscillation parameters (maximum displacement, mean velocity, and trajectory). Data acquisition was carried out with subjects standing while undergoing a 90-second test in four sensory conditions: eyes opened, eyes closed, on a stable surface, and on an unstable surface. RESULTS: Sensors 1 and 2 presented significant cross-correlations in all sensory conditions for both groups (r > 0.99; p < 0.001). No statistically significant differences were seen when the cross-correlations for both groups were compared. CONCLUSION: This study presented an important tool to analyze postural oscillation and assess the postural strategies of young and elderly subjects in different sensory conditions. Young and elderly individuals presented strong correlations between sensors (ankle strategy), but no statistically significant differences were seen between groups.

Software for subjective visual vertical assessment: an observational cross-sectional study.

UNLABELLED: Spatial orientation in relation to the gravitational axis is significantly important for the maintenance of the posture, gait and for most of the human's motor activities. The subjective visual vertical exam evaluates the individual's perception of vertical orientation. OBJECTIVES: The aims of this study were (1) to develop a virtual system to evaluate the subjective visual vertical exam, (2) to provide a simple tool to clinical practice and (3) to assess the subjective visual vertical values of healthy subjects using the new software. STUDY DESIGN: observational cross-sectional study. METHODS: Thirty healthy volunteers performed the subjective visual vertical exam in both static and dynamic conditions. The exam consisted in adjusting a virtual line in the vertical position using the computer mouse. For the static condition, the virtual line was projected in a white background. For the dynamic condition, black circles rotated in clockwise or counterclockwise directions. Six measurements were taken and the mean deviations in relation to the real vertical calculated. RESULTS: The mean values of subjective visual vertical measurements were: static -0.372º; ± 1.21; dynamic clockwise 1.53º ± 1.80 and dynamic counterclockwise -1.11º ± 2.46. CONCLUSION: This software showed to be practical and accurate to be used in clinical routines.

A new method to analyze the subjective visual vertical in patients with bilateral vestibular dysfunction.

OBJECTIVE: The aim of this study was to assess the subjective visual vertical in patients with bilateral vestibular dysfunction and to propose a new method to analyze subjective visual vertical data in these patients. METHODS: Static subjective visual vertical tests were performed in 40 subjects split into two groups. Group A consisted of 20 healthy volunteers, and Group B consisted of 20 patients with bilateral vestibular dysfunction. Each patient performed six measurements of the subjective visual vertical test, and the mean values were calculated and analyzed. RESULTS: Analyses of the numerical values of subjective visual vertical deviations (the conventional method of analysis) showed that the mean deviation was 0.326±1.13º in Group A and 0.301±1.87º in Group B. However, by analyzing the absolute values of the subjective visual vertical (the new method of analysis proposed), the mean deviation became 1.35±0.48º in Group A and 2.152±0.93º in Group B. The difference in subjective visual vertical deviations between groups was statistically significant (p<0.05) only when the absolute values and the range of deviations were considered. CONCLUSION: An analysis of the absolute values of the subjective visual vertical more accurately reflected the visual vertical misperception in patients with bilateral vestibular dysfunction.

Software para avaliação da subjetiva vertical visual: um estudo transversal observacional / Software for subjective visual vertical assessment: an observational cross-sectional study

A orientação espacial em relação ao eixo gravitacional é de suma importância para a manu tenção da postura, marcha e para a maioria das atividades motoras realizadas pelo ser humano. A subjetiva vertical visual é um exame que avalia a percepção individual de verticalidade. OBJETIVOS: Os objetivos deste estudo foram: (1) desenvolver um sistema virtual para avaliar a subjetiva vertical visual, (2) produzir uma ferramenta simples para a prática clínica e (3) medir os valores da subjetiva vertical visual em indivíduos saudáveis usando a nova ferramenta. Forma de estudo: estudo obser vacional transversal. MÉTODO: Trinta voluntários saudáveis realizaram a subjetiva vertical visual em ambas as condições, estática e dinâmica. O exame consistia em ajustar uma linha virtual na posição vertical usando o mouse do computador. Na condição estática, a linha virtual foi projetada em uma tela branca. Na condição dinâmica, círculos pretos giravam no sentido horário e anti-horário. Seis medidas foram feitas e o desvio médio em relação a vertical real, calculado. RESULTADOS: Os desvios médios da subjetiva vertical visual foram: estática -0,372º ± 1,21; dinâmica sentido horário 1,53º ± 1,80 e dinâmica sentido anti-horário -1,11º ± 2,46. CONCLUSÃO: Este software mostrou ser prático e preciso para ser inserido na rotina de exames clínicos.

Spatial orientation in relation to the gravitational axis is significantly important for the maintenance of the posture, gait and for most of the human's motor activities. The subjective visual vertical exam evaluates the individual's perception of vertical orientation. OBJECTIVES: The aims of this study were (1) to develop a virtual system to evaluate the subjective visual vertical exam, (2) to provide a simple tool to clinical practice and (3) to assess the subjective visual vertical values of healthy subjects using the new software. Study Design: observational cross-sectional study. METHODS: Thirty healthy volunteers performed the subjective visual vertical exam in both static and dynamic conditions. The exam consisted in adjusting a virtual line in the vertical position using the computer mouse. For the static condition, the virtual line was projected in a white background. For the dynamic condition, black circles rotated in clockwise or counterclockwise directions. Six measurements were taken and the mean deviations in relation to the real vertical calculated. RESULTS: The mean values of subjective visual vertical measurements were: static -0.372º; ± 1.21; dynamic clockwise 1.53º ± 1.80 and dynamic counterclockwise -1.11º ± 2.46. CONCLUSION: This software showed to be practical and accurate to be used in clinical routines.

A newmethod to analyze the subjective visual vertical in patients with bilateral vestibular dysfunction

OBJECTIVE: The aim of this study was to assess the subjective visual vertical in patients with bilateral vestibular dysfunction and to propose a new method to analyze subjective visual vertical data in these patients. METHODS: Static subjective visual vertical tests were performed in 40 subjects split into two groups. Group A consisted of 20 healthy volunteers, and Group B consisted of 20 patients with bilateral vestibular dysfunction. Each patient performed six measurements of the subjective visual vertical test, and the mean values were calculated and analyzed. RESULTS: Analyses of the numerical values of subjective visual vertical deviations (the conventional method of analysis) showed that the mean deviation was 0.326±1.13º in Group A and 0.301±1.87º in Group B. However, by analyzing the absolute values of the subjective visual vertical (the new method of analysis proposed), the mean deviation became 1.35±0.48º in Group A and 2.152±0.93º in Group B. The difference in subjective visual vertical deviations between groups was statistically significant (p,<0.05) only when the absolute values and the range of deviations were considered. CONCLUSION: An analysis of the absolute values of the subjective visual vertical more accurately reflected the visual vertical misperception in patients with bilateral vestibular dysfunction.

Influência da obesidade e da força de preensão palmar no equilíbrio postural estático de idosas ativas / Influence of obesity and handgrip strength in the static postural balance of active older women

O objetivo deste estudo foi investigar a influência da obesidade e da força de preensão palmar (FPP) no equilíbrio postural estático de idosas ativas nas condições de olhos abertos e fechados. Participaram 31 idosas (16 eutróficas e 15 obesas). A idade média e o Índice de Massa Corpórea (IMC) das eutróficas foram, respectivamente, 68,3±2,7 anos e 23,4±1,6kg/m², e das obesas 69,1±2,7 anos e 33,5±3kg/m². A FPP foi avaliada usando um dinamômetro (JAMAR). O equilíbrio postural estático foi avaliado usando um sistema tridimensional nas condições de olhos abertos (OA) e fechados (OF), durante 90 segundos cada condição. A FPP das idosas eutróficas foi 25,1±4,6kgf e das obesas foi 24,8±5,2kgf, não havendo diferenças significativas. No equilíbrio postural, foram observadas diferenças significativas entre os grupos apenas no deslocamento máximo a-p com AO (p=0,04) e OF (p<0,01), com as idosas obesas apresentando menor deslocamento a-p em relação às eutróficas. Não houve correlação entre o deslocamento máximo a-p com IMC e a FPP. No presente estudo FPP não influenciou o equilíbrio postural estático, enquanto a obesidade foi fator determinante de menor deslocamento ântero-posterior de idosas ativas.

The objective of this study was to investigate the influence of the obesity and handgrip strength on the static balance of active older women in the opened and closed eyes conditions. Thirty one women aged from 65 to 75 years (16 eutrophic and 15 obese) were evaluated. Mean age and BMI of the eutrophic women were, respectively, 68.3±2.7 years and 23.4±1.6kg/m², and of the obese women were 69.1±2.7 years and 33.5±3kg/m². Handgrip strength was evaluated using a dynamometer (JAMAR). A tridimensional sensors system was used to evaluate the static postural balance. The tests were performed for 90 seconds, with eyes opened and closed. The mean handgrip strength of the eutrophic women was 25.1±4.6kgf and of the obese women was 24.8±5.2kgf, (p>0,05). Significant differences between groups were only observed in the maximum displacement with opened eyes (p=0,04) and closed eyes(p<0,01). There was no correlation between the maximum displacement neither with the BMI or the handgrip strength. The present study showed smaller a-p displacement in obese than in eutrophic women, with major statistic difference in the eyes closed condition. In the present study, the handgrip strength did not influence the static balance, however the obesity was a determinant factor for the smaller a-p displacement of the active older women.

Static postural balance study in patients with vestibular disorders using a three dimensional electromagnetic sensor system.

UNLABELLED: The vestibular-ocular reflex assessment is important, but not enough. Tridimensional electromagnetic sensor systems represent a new method to assess posturography. AIM: To assess body sway in healthy subjects who had positive Dix Hallpike and Epley maneuvers and with other vestibular dysfunctions by means of a three-dimensional system. STUDY DESIGN: Prospective. MATERIALS AND METHODS: We had 23 healthy women, 15 with peripheral vestibular dysfunction found upon caloric test and 10 with positive Epley and Dix Hallpike maneuvers. All tests performed in the following positions: open and closed eyes on stable and unstable surfaces. RESULTS: With the Eyes Open and on a stable surface, p < 0.01 between the control group and the one with peripheral vestibular dysfunction in all variables, except the a-p maximum, full speed and mediolateral trajectory velocity, which had a p < 0.01 between the group with vestibular dysfunction and controls in all positions. The group with positive Epley and Dix Hallpike maneuvers had p < 0.01 at full speed and in its components in the x and y in positions with open and eyes closed on an unstable surface. CONCLUSION: The tridimensional electromagnetic sensors system was able to generate reliable information about body sway in the study volunteers.

Estudo do equilíbrio postural estático em pacientes com vestibulopatia mediante sistema de sensores eletromagnéticos tridimensionais / Static postural balance study in patients with vestibular disorders using a three dimensional eletromagnetic sensor system

A avaliação do reflexo vestíbulo ocular é importante; porém, insuficiente. Sistemas de sensores eletromagnéticos tridimensionais são uma nova opção para avaliação posturográfica. OBJETIVO: Avaliar a oscilação corporal em voluntários hígidos, com Manobras de Epley e Dix-Hallpike positivas e com outras disfunções vestibulares usando um sistema tridimensional. Forma de estudo: Prospectivo. MATERIAL E MÉTODO: Participaram: 23 mulheres saudáveis, 15 com disfunção vestibular periférica detectada à prova calórica e 10 com manobras de Epley e Dix-Hallpike positivas. Todas realizaram exames nas posições: olhos abertos e fechados em superfície estável e instável. RESULTADOS:Na condição Olhos Abertos e Superfície Estável, houve p < 0,01 entre o grupo controle e o com disfunção vestibular periférica em todas variáveis, exceto no deslocamento máximo a-p. Velocidade total e velocidade na trajetória médio-lateral apresentaram p < 0,01 entre o grupo com disfunção vestibular e o controle em todas as posições. O grupo com manobras de Epley e Dix-Hallpike positivas obteve p < 0,01 nas velocidades total e em seus componentes x e y nas posições de olhos abertos e fechados em superfície instável. CONCLUSÃO: O sistema de sensores eletromagnéticos tridimensionais utilizado foi capaz de gerar informações confiáveis quanto à oscilação corporal nos voluntários do estudo.

The vestibular-ocular reflex assessment is important, but not enough. Tridimensional electromagnetic sensor systems represent a new method to assess posturography. AIM: To assess body sway in healthy subjects who had positive Dix Hallpike and Epley maneuvers and with other vestibular dysfunctions by means of a three-dimensional system. Study design: Prospective. MATERIALS AND METHODS: We had 23 healthy women, 15 with peripheral vestibular dysfunction found upon caloric test and 10 with positive Epley and Dix Hallpike maneuvers. All tests performed in the following positions: open and closed eyes on stable and unstable surfaces. RESULTS: With the Eyes Open and on a stable surface, p < 0.01 between the control group and the one with peripheral vestibular dysfunction in all variables, except the a-p maximum, full speed and mediolateral trajectory velocity, which had a p < 0.01 between the group with vestibular dysfunction and controls in all positions. The group with positive Epley and Dix Hallpike maneuvers had p < 0.01 at full speed and in its components in the x and y in positions with open and eyes closed on an unstable surface. CONCLUSION: The tridimensional electromagnetic sensors system was able to generate reliable information about body sway in the study volunteers.

Dural defect repair in translabyrinthine acoustic neuroma surgery and its implications in cerebrospinal fluid leak occurrence.

Cerebrospinal fluid (CSF) leak is a complication that may occur after translabyrinthine (translab) acoustic neuroma (AN) removal. The aim of this study is to verify the incidence of CSF leak using two techniques for dural defect closure in translab AN surgery and present a new technique for dural repair. A retrospective study was held, reviewing charts of 34 patients in a tertiary neurotologic referral center. Out of these 34 patients that underwent translab AN excision in a 1-year period, 18 had their dural defect repaired using only abdominal fat graft and 16 using synthetic dura substitute (SDS) plus abdominal fat tissue. One patient (5.5%) in the first group had CSF leak and 1 (6.2%) in the second group had CSF leak postoperatively. Our data suggest that there are no significant differences in CSF leak rates using both techniques, although studies in a larger series must be undertaken to conclude it. We believe that the development of some points in the new technique for dural repair can achieve better results and reduce the CSF leak incidence in the translabyrinthine acoustic neuroma surgery in the near future.

Vestibular evoked myogenic potentials using low frequency stimuli.

UNLABELLED: Vestibular evoked myogenic potentials are vestibulocervical reflexes resulting from sacculus stimulation with strong intensity sounds. Normality parameters are necessary for young normal individuals, using low frequency stimuli, which configure the most sensitive region of this sensory organ. AIM: To establish vestibular evoked myogenic potential standards for low frequency stimulation. MATERIAL AND METHOD: Vestibular evoked myogenic potential was captured from 160 ears, in the ipsilateral sternocleidomastoid muscle, using 200 averaged tone-burst stimuli, at 250 Hz, with an intensity of 95 dB NAn. CASE STUDY: Clinical observational cross-sectional. RESULTS: Neither the student's t-test nor the Mann-Whitney test showed a significant difference in latency or vestibular evoked myogenic potential amplitudes, for p <; 0.05. Irrespective of gender, we found latencies of p13-n23 and p13-n23 interpeaks of 13.84 ms (± 1.41), 23.81 ms (± 1.99) and 10.62 ms (± 6.56), respectively. Observed values for amplitude asymmetry between the ears were equal to 13.48% for females and 3.81% for males. CONCLUSION: Low frequency stimuli generate vestibular evoked myogenic potentials, with adequate morphology and amplitude, thereby enabling the establishment of standard values for normal individuals at this frequency.

Potencial evocado miogênico vestibular a baixas frequências de estimulação / Vestibular evoked myogenic potentials using low frequency stimuli

Os potenciais evocados miogênicos vestibulares são reflexos vestíbulo-cervicais, decorrentes da estimulação do sáculo com sons de forte intensidade. São necessários parâmetros de normalidade para indivíduos jovens normais, utilizando-se estímulos a baixas frequências, as quais configuram a região de maior sensibilidade desse órgão sensorial. OBJETIVO: Realizar normatização do potencial evocado miogênico vestibular para baixas frequências de estimulação. MATERIAL E MÉTODO: Captou-se o potencial evocado miogênico vestibular em 160 orelhas, no músculo esternocleidomastoideo, de forma ipsilateral, por meio da promediação de 200 tone bursts, frequência de 250 Hz, intensidade de 95 dB NAn. FORMA DE ESTUDO: Estudo de coorte contemporânea com corte transversal. RESULTADOS: Aplicando-se o teste T de Student ou o Teste de Mann-Whitney, não foi constatada diferença significativa para parâmetros do potencial evocado miogênico vestibular entre os gêneros, para p <; 0,05. Verificamos, independente do gênero, latências de p13, n23 e interpicos p13-n23 iguais a 13,84ms (± 1,41), 23,81ms (±1,99) e 10,62ms (± 6,56), respectivamente. Observamos índices de assimetria iguais a 13,48 por cento para mulheres e 3,81 por cento para homens. CONCLUSÃO: Estímulos de baixa frequência geram respostas de potenciais evocados miogênicos vestibulares, com morfologia e amplitudes adequadas, sendo determinados, valores de normalidade para essa frequência, em indivíduos normais.

Vestibular evoked myogenic potentials are vestibulocervical reflexes resulting from sacculus stimulation with strong intensity sounds. Normality parameters are necessary for young normal individuals, using low frequency stimuli, which configure the most sensitive region of this sensory organ. AIM: To establish vestibular evoked myogenic potential standards for low frequency stimulation. MATERIAL AND METHOD: Vestibular evoked myogenic potential was captured from 160 ears, in the ipsilateral sternocleidomastoid muscle, using 200 averaged tone-burst stimuli, at 250 Hz, with an intensity of 95 dB NAn. CASE STUDY: Clinical observational cross-sectional. RESULTS: Neither the student's t-test nor the Mann-Whitney test showed a significant difference in latency or vestibular evoked myogenic potential amplitudes, for p <; 0.05. Irrespective of gender, we found latencies of p13-n23 and p13-n23 interpeaks of 13.84 ms (± 1.41), 23.81 ms (±1.99) and 10.62 ms (± 6.56), respectively. Observed values for amplitude asymmetry between the ears were equal to 13.48 percent for females and 3.81 percent for males. CONCLUSION: Low frequency stimuli generate vestibular evoked myogenic potentials, with adequate morphology and amplitude, thereby enabling the establishment of standard values for normal individuals at this frequency.

The use of a neck brace does not influence visual vertical perception.

UNLABELLED: Subjective visual vertical (SVV) evaluates the individual's capacity to determine the vertical orientation. Using a neck brace (NB) allow volunteers' heads fixation to reduce cephalic tilt during the exam, preventing compensatory ocular torsion and erroneous influence on SVV result. OBJECTIVE: To analyze the influence of somatosensory inputs caused by a NB on the SVV. METHOD: Thirty healthy volunteers performed static and dynamic SVV: six measures with and six without the NB. RESULTS: The mean values for static SVV were -0.075º±1.15º without NB and -0.372º±1.21º with NB. For dynamic SVV in clockwise direction were 1.73º±2.31º without NB and 1.53º±1.80º with NB. For dynamic SVV in counterclockwise direction was -1.50º±2.44º without NB and -1.11º±2.46º with NB. Differences between measurements with and without the NB were not statistically significant. CONCLUSION: Although the neck has many sensory receptors, the use of a NB does not provide sufficient afferent input to change healthy subjects' perception of visual verticality.

The use of a neck brace does not influence visual vertical perception / O uso do colar cervical não influência na percepção de verticalidade visual

Subjective visual vertical (SVV) evaluates the individual's capacity to determine the vertical orientation. Using a neck brace (NB) allow volunteers' heads fixation to reduce cephalic tilt during the exam, preventing compensatory ocular torsion and erroneous influence on SVV result. OBJECTIVE: To analyze the influence of somatosensory inputs caused by a NB on the SVV. METHOD: Thirty healthy volunteers performed static and dynamic SVV: six measures with and six without the NB. RESULTS: The mean values for static SVV were -0.075º±1.15º without NB and -0.372º±1.21º with NB. For dynamic SVV in clockwise direction were 1.73º±2.31º without NB and 1.53º±1.80º with NB. For dynamic SVV in counterclockwise direction was -1.50º±2.44º without NB and -1.11º±2.46º with NB. Differences between measurements with and without the NB were not statistically significant. CONCLUSION: Although the neck has many sensory receptors, the use of a NB does not provide sufficient afferent input to change healthy subjects' perception of visual verticality.

A subjetiva vertical visual (SVV) avalia a capacidade do indivíduo determinar a posição vertical. O uso do colar cervical (CC) fixa a cabeça do voluntário, reduzindo a inclicação cefálica durante o exame e prevenindo a torção ocular compensatória que influencia na SVV. OBJETIVO: Analisar a influência de informações sometossensoriais causadas pelo uso de um CC na SVV. MÉTODO: Trinta voluntários saudáveis realizaram a SVV estática e dinâmica: seis medidas com e seis medidas sem o CC. RESULTADOS: O valor médio da SVV estática foi -0,075º±1,15º sem CC e -0,372º±1,21º com. Na SVV dinâmica no sentido horário foi 1,73º±2,31º sem CC e 1,53º±1,80º com. Na SVV dinâmica no sentido anti-horário foi -1,50º±2,44º sem CC e -1,11º±2,46º com. As diferenças entre as medidas com e sem CC não foram estatisticamente significativas. CONCLUSÃO: Apesar de o pescoço possuir inumeros receptores sensoriais, o uso do CC não fornece aferências suficientes para alterar a percepção de visual de verticalidade de voluntários saudáveis.

Saccular sensitivity function measured by vestibular evoked myogenic potential.

CONCLUSIONS: Vestibular myogenic potential responses were present when evoked by tone burst stimuli of 250, 500, 1000, and 2000 Hz; however, they were more effective for low-frequency stimuli. OBJECTIVES: Few studies refer to specific frequency sensitivities of the saccular afferents. Accordingly, the aim of the present study was to analyze p13 and n23 latency and amplitude parameters of vestibular evoked myogenic potential (VEMP) captured with tone bursts at frequencies of 250, 500, 1000, and 2000 Hz. METHODS: VEMP was captured in 156 ears (78 subjects), recorded in the sternocleidomastoid muscle, averaging 200 stimuli, stimulus rate of 5 Hz, duration 10 ms (rise, 4 ms; plateau, 2 ms; fall, 4 ms), at intensity of 95 dB nHL. The recordings were performed in 50 ms windows. RESULTS: We found lower p13 latencies in women compared with men, except for the frequency of 250 Hz. We found higher mean absolute latency values for p13 and n13 and lower p13-n13 amplitude and p13-n13 inter-peak values for a frequency of 2000 Hz. Higher amplitudes were observed at frequencies of 250 and 500 Hz. When frequencies of 250, 500, 1000, and 2000 Hz were compared using ANOVA, we found statistically significant differences for all the VEMP parameters (p ≤ 0.005).

Analysis of static postural balance using a 3d electromagnetic system.

UNLABELLED: Early detection of postural disorders is essential for timely interventions in patients with imbalance. AIM: A pilot study describing a new tool for evaluating static postural balance. STUDY DESIGN: A cross-sectional study of a contemporary series. MATERIAL AND METHOD: Twenty-five volunteers (15 women and 10 men) were evaluated. The mean age was 25.8 ± 4.2 years, the mean weight was 63.9 ± 13.1Kg, the mean height was 1.68 ± 0.08 m and the body mass index was 22.3±3.3kg/m2. Posturography was done by analysing postural sway with an electromagnetic system; a sensor was attached to the skin over the spinous process of the first thoracic vertebra. Tests were carried out with the subjects in the orthostatic position for 90 seconds, with eyes opened(EO) and closed(EC) on stable and unstable surfaces. RESULTS: When the influence of the surface was analyzed (stable x unstable) in the EO condition, there were significant differences in the middle-lateral parameters (m-l) (p=0.004) and total path (p=0.01), and in the m-l (p=0.004) and total (p=0.014) speed. In the EC condition, there were significant differences in all parameters (p<0.001). The influence of the vision was observed in all parameters only on unstable surfaces (p<0.05). CONCLUSION: The new tool was efficient for analysing postural sway.

Potencial miogênico evocado vestibular: proposição de um novo instrumento / Vestibular evoked myogenic potential: we propose a new instrument

Introdução: Atualmente, ainda não existe um instrumento específico para a avaliação dos potencias miogênicos evocados vestibulares, sendo a mesma realizada por meio de um equipamento desenvolvido para a captação de potenciais evocados auditivos, disponível no mercado. Assim, as funções de amplificação, filtragem, estimulação, janela de captação, rejeição de artefatos e características de promediação, bem como o próprio software de gerenciamento, ficam muito a desejar para a nova função que lhe é atribuída. Objetivo: Comparar latências e amplitudes das componentes p13 e n23, e os índices de assimetria, entre um equipamento considerado padrão-ouro (EP25), adaptado para o registro deste potencial, e o novo equipamento desenvolvido. Método: Estudo experimental com 11 ouvintes normais. A partir de estímulos sonoros tone-burst de 10 ms, frequência de 500 Hz, com intensidade de 90 dBNAn, foram registrados potenciais miogênicos evocados com janelas de 80 ms. Resultados: Pode-se constatar ausência de diferenças significativas, quando comparados os dois instrumentos, quanto aos parâmetros de latência e amplitude, exceto para a latência de n23, com valor de p = 0,005. O valor do índice de assimetria inter-pico p13-n23, para o novo aparelho (20,1%), foi significativamente menor que o encontrado para o EP25 (30,5%), com p menor que 0,01. Conclusão: Desta forma, conclui-se, que não existem diferenças para as latências e amplitudes do VEMP entre o EP25 e o novo dispositivo desenvolvido, apresentando, este último, maior proximidade com os valores descritos na literatura e menor índice de assimetria da amplitude inter-pico p13-n23. Forma de estudo: prospectivo, clínico e experimental. Identifier: NCT01132105...

Introduction: Currently, there is still no specific instrument for assessment of vestibular evoked myogenic potentials, with the same performed by a device designed to capture auditory evoked potentials available in the market. Thus, the functions of amplification, filtering, stimulation, window capture, rejection of artifacts and features of averaging, as well as its management software, are much to be desired for the new role assigned to it. Objective: To compare latencies and amplitudes of components p13 and n23, and the indices of asymmetry between a devices considered the gold standard (EP25), adapted to record the potential and the new equipment developed. Method: An experimental study with 11 normal hearing. From the tone-burst sound stimuli of 10 ms, frequency of 500 Hz with intensity 90 dBNAn, evoked myogenic potentials were recorded with 80 ms windows. Results: You can see no significant differences when comparing the two instruments regarding the parameters of latency and amplitude, except for the latency of n23, with p = 0.005. The value of asymmetry index inter-p13-n23 peak for the new unit (20.1%) was significantly lower than that found for the EP25 (30.5%), with p less than 0.01. Conclusion: Thus, we conclude that there are no differences for the latencies and amplitudes of VEMP between the EP25 and the new device developed by presenting the latter, closer to the values reported in literature and a lower index of asymmetry of amplitude between p13-n23 peak. Study form: Prospective clinical and experimental. Identifier: NCT01132105...

Análise do equilíbrio postural estático utilizando um sistema eletromagnético tridimensional / Analysis of static postural balance using a 3d electromagnetic system

A detecção precoce de distúrbios posturais é fundamental para a promoção de intervenções adequadas para pacientes com desequilíbrios. OBJETIVO: Este é um estudo piloto que descreve uma nova ferramenta para avaliação do equilíbrio postural estático. FORMA DE ESTUDO: Coorte contemporânea com corte transversal. MATERIAL E MÉTODO: Foram avaliados 25 voluntários (15 mulheres e 10 homens). Idade média de 25,8±4,2anos, peso 63,9±13,1Kg, estatura 1,68±0,08m e índice de massa corporal 22,3±3,3kg/m2. A posturografia foi realizada por meio da análise de oscilação postural utilizando um equipamento eletromagnético com um sensor fixado sobre o processo espinhoso da 1ª vértebra torácica. Os testes foram realizados com os sujeitos na posição ortostática durante 90 segundos, para as condições de olhos abertos (OA) e fechados (OF) em superfície estável e instável. RESULTADOS: Quando analisada a influência da superfície (estável x instável) para o equilíbrio postural na condição OA, foram observadas diferenças significativas nos parâmetros de trajetória médio-lateral (m-l) (p=0.004) e total (p=0.014) e de velocidade m-l (p=0.004) e total (p=0.014). Na condição OF, foram observadas diferenças significativas em todos os parâmetros estudados (p<0.001). Houve influência da visão em todos os parâmetros apenas na superfície instável (p<0.05). CONCLUSÃO: A ferramenta utilizada se mostrou eficaz para a análise da oscilação postural.

Early detection of postural disorders is essential for timely interventions in patients with imbalance. AIM: A pilot study describing a new tool for evaluating static postural balance. STUDY DESIGN: A cross-sectional study of a contemporary series. MATERIAL AND METHOD: Twenty-five volunteers (15 women and 10 men) were evaluated. The mean age was 25.8 ± 4.2 years, the mean weight was 63.9 ± 13.1Kg, the mean height was 1.68 ± 0.08 m and the body mass index was 22.3±3.3kg/m2. Posturography was done by analysing postural sway with an electromagnetic system; a sensor was attached to the skin over the spinous process of the first thoracic vertebra. Tests were carried out with the subjects in the orthostatic position for 90 seconds, with eyes opened(EO) and closed(EC) on stable and unstable surfaces. RESULTS: When the influence of the surface was analyzed (stable x unstable) in the EO condition, there were significant differences in the middle-lateral parameters (m-l) (p=0.004) and total path (p=0.01), and in the m-l (p=0.004) and total (p=0.014) speed. In the EC condition, there were significant differences in all parameters (p<0.001). The influence of the vision was observed in all parameters only on unstable surfaces (p<0.05). CONCLUSION: The new tool was efficient for analysing postural sway.