Saccadic movements during an exploratory visual search task in patients with glaucomatous visual field loss

ABSTRACT Purpose: To evaluate the saccadic movements of patients with visual field loss due to primary open-angle glaucoma. Methods: Thirteen patients with good visual acuity (0.2 logMAR or better) (seven patients with primary open-angle glaucoma 65 ± 13 years) and six controls (51 ± 6 years) yielded a comprehensive ophthalmological examination, including Humphrey Visual Field tests (SITA-Standard 24-2), and performed a monocular, exploratory digital visual search task that quantifies the duration for finding the number "4" on a random array of digits distributed on the screen. After individual adjustments of the angle and distance positioning, the screen was spatially matched with the 24-2 visual field, and divided into five areas for analysis. During the task, saccades were simultaneously recorded in the same eye with a video-based eye tracker. Results: The patients with primary open-angle glaucoma showed a significantly higher number of saccades/screen (median ± interquartile range, 59.00 ± 29.00 vs. 32.50 ± 19.75 saccades (p=0.027) and visual search time per screen (38.50 ± 60.14 vs. 23.75 ± 8.90 seconds (p=0.035) than the controls did. Although the univariate analysis indicated a significant correlation with visual field mean deviation (coefficient=26.19 (p=0.02), only the visual search time/screen was significantly associated with the number of saccades/screen in the multivariate regression model (coefficient=0.55 (p<0.001). Overall, no significant correlation was observed between the sectorial number of saccades and the sensitivity of the five visual field areas. Conclusions: The patients with primary open-angle glaucoma show impaired search performance and showed a higher number of saccades needed to find stimuli when performing the exploratory visual task.

Long-term impact of mild traumatic brain injury on oculomotor parameters / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To evaluate the long-term impact of mild traumatic brain injury(mTBI)on oculomotor parameters.METHODS: Prospective study. A total of 46 patients from 6 to 12mo after mTBI who visited Tianjin Eye Hospital from February to August 2021 were collected. According to the score of the Brain Injury Vision Sympton Survey(BIVSS)Questionnaire, they were divided into the symptomatic group of mTBI(BIVSS total score ≥32, n=24)and the asymptomatic group of mTBI(BIVSS total score &#x0026;#x003C;32, n=22). In addition, healthy people without mTBI were selected as the control group(n=23). All of the subjects accepted test of oculomotor parameters to evaluate binocular vision.RESULTS: Monocular accommodation amplitude, monocular accommodation facility, the absolute value of phoria at near, BI recovery point of fusional range at near and saccades were different among the three groups(P&#x0026;#x003C;0.05); There were no significant differences in near point of convergence, the absolute value of distance phoria, BI blur, BO blur and recovery of fusional range at near among the three groups(P&#x0026;#x003E;0.05). The incidence of accommodative abnormality, convergence abnormality, and saccadic dysfunction were different among the three groups(P&#x0026;#x003C;0.01). The incidence of accommodative abnormality in the symptomatic group was significantly higher than that in the asymptomatic and control groups(all P&#x0026;#x003C;0.0167); the incidence of convergence dysfunction in the symptomatic and the asymptomatic groups were higher than that in the control group(all P&#x0026;#x003C;0.0167); the incidence of saccadic dysfunction in the symptomatic group was significantly higher than that in the asymptomatic and control groups(all P&#x0026;#x003C;0.0167).CONCLUSION: Accommodation, convergence, and saccades functions in the mTBI symptomatic group were lower, and some of the binocular vision in the asymptomatic group was also affected. It is suggested that mTBI has a long-term impact on oculomotor parameters, and comprehensive oculomotor assessment is necessary for mTBI patients.

Differences between hemispheres and in saccade latency regarding volleyball athletes and non-athletes during saccadic eye movements: an analysis using EEG / Diferenças inter-hemisféricas e na latência sacádica entre atletas de voleibol e não atletas durante movimentos oculares sacádicos: uma análise usando EEG

Abstract Background The saccadic eye movement is responsible for providing focus to a visual object of interest to the retina. In sports like volleyball, identifying relevant targets quickly is essential to a masterful performance. The training improves cortical regions underlying saccadic action, enabling more automated processing in athletes. Objective We investigated changes in the latency during the saccadic eye movement and the absolute theta power on the frontal and prefrontal cortices during the execution of the saccadic eye movement task in volleyball athletes and non-athletes. We hypothesized that the saccade latency and theta power would be lower due to training and perceptual-cognitive enhancement in volleyball players. Methods We recruited 30 healthy volunteers: 15 volleyball athletes (11 men and 4 women; mean age: 15.08 ± 1.06 years) and 15 non-athletes (5 men and 10 women; mean age: 18.00 ± 1.46 years). All tasks were performed simultaneously with electroencephalography signal recording. Results The latency of the saccadic eye movement presented a significant difference between the groups; a shorter time was observed among the athletes, associated with the players' superiority in terms of attention level. During the experiment, the athletes observed a decrease in absolute theta power compared to non-athletes on the electrodes of each frontal and prefrontal area. Conclusion In the present study, we observed the behavior of reaction time and absolute theta power in athletes and non-athletes during a saccadic movement task. Our findings corroborate the premise of cognitive improvement, mainly due to the reduction of saccadic latency and lower beta power, validating the neural efficiency hypothesis.

Resumo Antecedentes O movimento ocular sacádico é responsável por dar foco a um objeto visual de interesse para a retina. Em esportes como o vôlei, identificar alvos relevantes o mais rápido possível é essencial para se ter um desempenho magistral. O treinamento melhora as regiões corticais subjacentes à ação sacádica, e permite um processamento mais automatizado em atletas. Objetivo Investigamos as mudanças na latência durante o movimento ocular sacádico e a potência teta absoluta nos córtices frontal e pré-frontal durante a execução da tarefa de movimento ocular sacádico em atletas e não atletas de voleibol. Nossa hipótese é a de que a latência sacádica e a potência teta seriam menores em atletas devido ao treinamento e ao aprimoramento perceptivo-cognitivo em jogadores de voleibol. Métodos Ao todo, 30 voluntários saudáveis foram recrutados para este estudo: 15 atletas de voleibol (11 homens e 4 mulheres; idade média: 15,08 ± 1,06 anos) e 15 não atletas (5 homens e 10 mulheres; idade média: 18,00 ± 1,46 anos). Todas as tarefas foram realizadas simultaneamente com o registro do sinal eletroencefalográfico. Resultados O resultado da latência do movimento ocular sacádico apresentou diferença significativa entre os grupos, sendo observado menor tempo entre os atletas, associado à superioridade dos jogadores em termos de nível de atenção. Durante o experimento, nos eletrodos de cada área frontal e pré-frontal, observou-se uma diminuição na potência teta absoluta nos atletas em comparação aos não atletas. Conclusão Neste estudo, observou-se o comportamento do tempo de reação e da potência teta absoluta em atletas e não atletas durante uma tarefa de movimento sacádico. Nossos achados corroboram a premissa de melhora cognitiva, principalmente pela redução da latência sacádica e menor potência beta, o que valida a hipótese de eficiência neural.

Importance of Vestibulo-ocular Reflex Gain and Refixation Saccade Analysis in Individuals with Auditory Neuropathy Spectrum Disorder

Abstract Introduction Auditory neuropathy spectrum disorder (ANSD) features the presence of otoacoustic emissions, poor speech identification score and absent auditory brainstem response. Objective The present study was designed to evaluate the functioning of all six semicircular canals in individuals with ANSD and to compare it with those of normalhearing individuals. Methods A total of 50 individuals participated in the present study, in which Group I comprised25normal-hearingindividuals, and GroupII comprised25individualswithANSD. All of the participants underwent case history, pure tone audiometry, immittance, otoacoustic emissions, auditory evoked response and video head impulse test (vHIT). Results The independent sample t-test revealed significantly lower vestibulo-ocular reflex gain values in individuals with ANSD. A presence of 100% corrective refixation saccades was observed in the same group. The Pearson correlation test revealed no significant correlation between vestibulo-ocular reflex (VOR) gain with duration of hearing loss and pure tone thresholds for any of the three orthogonal planes. The chisquared test revealed no association between the VOR gain values and the presence or absence of saccades in any of the semicircular canals (p>0.05). Conclusion Huge percentages of individuals with ANSD have been found to have associated vestibular dysfunction as well. Therefore, the vHIT can be used as one of the important tests of the vestibular test battery to evaluate all six semicircular canals in individuals with ANSD.

Abnormal eye movements in patients with idiopathic rapid eye movement sleep behavior disorder / 浙江大学学报·医学版

OBJECTIVE@#To analyze the characteristics of eye movements in patients with idiopathic rapid eye movement sleep behavior disorder (iRBD).@*METHODS@#Twenty two patients with iRBD and 20 controls were enrolled between January 2017 and May 2019 from Sir Run Run Shaw Hospital, Zhejiang University School of Medicine. Clinical data including polysomnogram (PSG) results were collected. Videonystagmography (VNG) including spontaneous nystagmus, gaze, saccade, tracking and optokinetic test were performed. The difference of VNG results between iRBD patients and controls were analyzed. The factors related to the abnormal VNG results were analyzed by using logistic regression analysis.@*RESULTS@#No significant differences were found between the iRBD and control groups in the spontaneous nystagmus, gaze nystagmus, square wave jerk, involuntary eye movement, saccade and optokinetic nystagmus (all >0.05). In smooth pursuit of 0.4-0.5 Hz and 0.6-0.7 Hz, iRBD patients had more type Ⅲ-Ⅳ curve than controls (=5.177 and 5.301, both <0.05). Logistic regression analysis indicated that less sleep time of N3 stage was related to the abnormal results in smooth pursuit of 0.4-0.5 Hz (=0.963, <0.05). iRBD patients with Ⅲ-Ⅳ type curve in smooth pursuit of 0.4-0.5 Hz had less N3 sleep time than iRBD patients with Ⅰ-Ⅱ type curve (52±28 min vs. 76±23 min, =2.197, <0.05).@*CONCLUSIONS@#Abnormal smooth pursuit was found in iRBD patients, which might be related to the pathological mechanism of iRBD.

Abnormal Eye Movements in Parkinsonism and Movement Disorders

Abnormal eye movements are commonly observed in movement disorders. Ocular motility examination should include bedside evaluation and laboratory recording of ocular misalignment, involuntary eye movements, including nystagmus and saccadic intrusions/oscillations, triggered nystagmus, saccades, smooth pursuit (SP), and the vestibulo-ocular reflex. Patients with Parkinson's disease (PD) mostly show hypometric saccades, especially for the self-paced saccades, and impaired SP. Early vertical saccadic palsy is characteristic of progressive supranuclear palsy-Richardson's syndrome. Patients with cortico-basal syndrome typically show a delayed onset of saccades. Downbeat and gaze-evoked nystagmus and hypermetric saccades are characteristic ocular motor findings in ataxic disorders due to cerebellar dysfunction. In this review, we discuss various ocular motor findings in movement disorders, including PD and related disorders, ataxic syndromes, and hyperkinetic movement disorders. Systemic evaluation of the ocular motor functions may provide valuable information for early detection and monitoring of movement disorders, despite an overlap in the abnormal eye movements among different movement disorders.

Analysis of Age-Dependent Normative Values of Suppression Video-Head-Impulse Test in Healthy Korean Subjects / 대한평형의학회지

OBJECTIVES: Suppression head impulse paradigm (SHIMP) in video head impulse test is now newly used to test vestibular function. The aim of this study was to analyze normative values of SHIMP for healthy Korean subjects in each decade of life. METHODS: SHIMP and HIMP responses were measured with the video head impulse test in 70 healthy subjects. Vestibulo-ocular reflex gain and anticompensatory saccade were analyzed and compared at each decade of life. RESULTS: All subjects produced anticompensatory saccades in SHIMP. Gain values did not vary significantly with age. Gain values in SHIMP were lower than gain values in HIMP. The gain values of rightward impulse were higher than the gain values of leftward impulse. CONCLUSIONS: Gain values and anticompensatory saccades in SHIMP were consistently equal in each decade of life. Normative values of SHIMP seems largely unaffected by aging.

Normal Vestibulo Ocular Reflex (VOR) gain Measured Using the Video Head Impulse Test (vHIT) in Healthy Young Adults

@#Introduction: Many new objective tests to assess the function of specific structures of the vestibular organ are currently adopted in vestibular clinics. One of the objective assessments include the video head impulse test (vHIT) where gain & velocity responses of eye relative to the head movements are recorded using an infrared camera. Methods: Thirty normal hearing subjects age between 18 to 25 years old participated in this study. At least ten Lateral, Left Anterior Right Posterior (LARP), and Right Anterior Left Posterior (RALP) responses were recorded for each participant by making small and rapid unpredictable head movements. Results: The average velocity gain for Lateral responses at 40 ms, 60 ms and 80 ms were 1.05 ± 0.003, 1.03 ± 0.002 and 1.01 ± 0.003 respectively. The LARP average velocity regression were 1.01 ± 0.24 for Left Anterior and 1.05 ± 0.25 for Right Posterior, with an average gain asymmetry of 5.13%. The RALP average velocity regression were 1.08 ± 0.31 for Right Anterior and 1.12 ± 0.30 for Left Posterior, with an average gain asymmetry of 5.87%. One sample T-test were conducted to compare Lateral responses to a previous study by Mossman et al. (2015) where significant differences in velocity gain at 60 ms and 80 ms between studies were found where, t (59) = 5.56, p <0.01 and t (59) = 2.86, p < 0.01 respectively. Conclusion: This indicates the importance of establishing on-site norms for every clinical settings as techniques used and equipment differences could affect the results.

Research progress of oculomotor disorder in Parkinson's disease / 中华神经科杂志

Parkinson's disease (PD) is a common neurodegenerative disease characterized by bradykinesia,resting tremor,muscle rigidity,and abnormal gait posture.Ocular motor function test plays an important part in neurological examinations.It has been widely accepted that specific ocular motor patterns contribute to diagnosis of Parkinsonian syndrome including progressive supranuclear palsy and multiple system atrophy.However,recent studies have shown that patients of PD may also exhibit specific eye movement disorders,which will be helpful in the early diagnosis,evaluation and differential diagnosis of PD.In 2015,the Movement Disorder Society clinical diagnostic criteria for Parkinson's disease suggested that sustained staring evoked nystagmus could be used as an exclusive criterion for PD.The clinical features,detection methods and clinical significance of oculomotor dysfunction in PD are reviewed in this article.

Can a lexical decision task predict efficiency in the judgment of ambiguous sentences?

Abstract The lexicon plays a fundamental role in reading, but little is known about how it influences reading efficiency. Thus, this study seeks to identify which lexical factors in a lexical decision task are relevant in a semantic decision test. A total of 33 university students were recruited to perform a lexical decision task and a semantic decision task. The results revealed differences between the three types of words in the lexical decision task for all measures, but only in the regressive saccades for the semantic decision task. Ambiguous sentences triggered fewer regressions than sentences related to objects. The only lexical measure found to predict efficiency was average time on regular words, which predicted 24% of the efficiency. We discuss the implications of the use of a lexical decision task and the use of the inverse efficiency score as a semantic measure, and we discuss how the lexicon can predict semantic comprehension.

Clinical Feasibility of Suppression Head Impulse Test in Vestibulopathy Patients / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: The suppression head impulse (SHIMP) test has emerged as one of the new vestibular function tests. The SHIMP test is an analysis of anti-compensatory saccadic movements in gazing moving targets as the head moves. In this study, we investigated the accuracy and sensitivity of the test. SUBJECTS AND METHOD: We analyzed the results of SHIMP test (gain, amplitude, and latency) in 24 cases, which included normal, vestibular neuritis, benign paroxysmal positional vertigo (BPPV), Meniere's disease, bilateral vestibular function loss, temporal bone fracture, tuberculosis meningitis and acoustic schwannoma patients. We also carried out a physical exam, audiologic study, video electronystagmography (vENG) and a conventional video head impulse test to evaluate the feasibility of SHIMP test in cases of vesitibulopathy. RESULTS: In patients with vestibulopathy, the analysis of SHIMP test indicated high sensitivity and accuracy, which were supported by accompanying audio-vestibular studies. Patients suspected with BPPV, vestibular neuronitis and Meniere's disease showed low vestibulo ocular reflex (VOR) gain and delayed anticompensatory saccade with smaller and more scattered amplitudes than the control. Patients with bilateral vestibular function loss, temporal bone fracture, tuberculosis meningitis, and acoustic schwannoma showed delayed latency, and small amplitude or few anticompensatory saccades. Finally, changes in the SHIMP test values might be a hint that patients had recovered from vestibular neuronitis and tuberculosis meningitis. CONCLUSION: We found the feasibility of SHIMP test in detecting the pathologic condition of VOR in vestibulopathy patients. We argue that the usefulness of SHIMP test might be extended to evaluating the effectiveness of rehabilitation.

Professor Wadia's contributions to neurology and spinocerebellar ataxia type 2 / A contribuição do professor Wadia à neurologia e a ataxia espinocerebelar tipo 2

ABSTRACT The authors present a historical review of the seminal contributions of Professor N. H. Wadia (1925-2016) to neurology, in particular, the first description of spinocerebellar ataxia type 2.

RESUMO Os autores apresentam uma revisão histórica sobre a contribuição seminal do Professor N.H. Wadia para a Neurologia, em particular, a primeira descrição mundial da ataxia espinocerebelar tipo 2.

Refração e síndrome de fadiga visual no uso de sistema de televisão ULTRA- HD-3D- 4K de tela curva / Refraction and visual fatigue syndrome on watching the ULTRA HD 4k television curved screen system

RESUMO Objetivo: Avaliar uma possível desordem de sensibilidade ocular (similar a glare), com sintomas de fadiga visual, através da observação de tela de televisão ULTRA HD- 3D- 4K de tela curva de 55 polegadas, em voluntários com exame oftalmológico normal. Métodos: Um estudo prospectivo, longitudinal, caso-controle, com formação de grupos por faixa etária e com critérios de inclusão e exclusão. Uma comparação de um vídeo documentário gravado com resolução HD 4K e o mesmo documentário gravado em FULL HD antes e após a tele-audiência anterior consistindo numa avaliação de três fases do estudo com os mesmos critérios. A fadiga visual foi analisada por meio de um questionário padronizado de queixas de síndrome de fadiga visual comuns e comparado a teste de sensibilidade ao contraste, teste de amplitude de acomodação e convergência, teste de frequência de piscar e teste de movimentos sacádicos conjugados oculares de grande amplitude. Equipamentos acessórios como tablets com câmara digitais serão utilizados para gravação de vídeos da frequência de piscar, e de movimentos oculares sacádicos durante toda a audiência televisiva. Analise estatística com Teste de Qui quadrado, teste t de Student, teste de Tukey e teste F com analise de Variância foram feitos para dados em tabelas de contingência e gráficos caixa em Box Plot. Nível de significância estimado em 5%. Resultados: Oitenta voluntários normais foram avaliados e avaliados como inferência de expressividade estatística alpha (α) de 10%, sem obter significância de 5% para as queixas de um questionário de Síndrome de Fadiga Visual. Outros testes estatísticos revelam dados de significância de 5% numa inferência global da pesquisa quanto à frequência de piscar e de movimentos sacádicos conjugados oculares de grande amplitude. Conclusão: Telas de televisão de alta resolução ULTRA HD 4K, podem provocar queixas de fadiga visual numa população de características pouco comuns (com baixa frequência de piscar palpebral e movimentos sacádicos conjugados), mas existentes. O baixo índice de estatística significativa poderá revelar-se de maior expressão no uso de uma amostragem de pesquisa mais numerosa. Os autores chamam a atenção para a possibilidade de incremento desse efeito de fadiga visual no futuro advento de Sistema de Televisão ULTRA HD 8K.

ABSTRACT Purpose: To evaluate eye sensitivity disorder (similar to glare), with symptoms of visual fatigue, through watching television ULTRA HD3D-55-inch 4K curved screen among volunteers with normal eye examination. Methods: A prospective, longitudinal, case-control study, with inclusion and exclusion criteria and groups formation enrolled by age range. A comparison of a video documentary presented with the ULTRA HD TV 4K and with the FULL HD TV before and after the previous tele-audience, consisting of an evaluation of three phases of the study regarding the case-control criteria. The main variable analyzed was a questionnaire of visual fatigue syndrome complaints which was compared with secondary variables as the contrast sensitivity test, amplitude of accommodation test, blink frequency test, and test of conjugated saccadic eye movements of big amplitude. Tablets with digital camera equipment were used for video recording of the blink frequency, and saccadic eye movements throughout the television audience. Statistical analysis with Chi Square test. Results: Eighty healthy volunteers were evaluated and assessed as expressiveness of statistical inference alpha (α) of 10%, without obtaining significance of 5% for complaints of a questionnaire Visual Fatigue Syndrome. Other statistical tests showed 5% of significance of data in a global inference research on the frequency of blinking and combined saccadic movements of great amplitude. Conclusion: High resolution television screens ULTRA HD 4K may cause complaints of eyestrain in a population with some uncommon characteristics (low eyelid blink frequency and conjugated saccades movements). The low statistical significant index could be increased in a research with a higher number of participants. The authors call attention to the possibility of increasing this visual fatigue effect in the future advent of Television System ULTRA HD 8K.

Isolated Infarction of Anterior Cerebellar Vermis / 대한평형의학회지

The anterior cerebellar vermis has been known to act in coordination of gait and postural adjustment of the trunk and legs. However, oculomotor abnormalities in an isolated anterior vermian lesion have not been described in the literature. A 59-year-old man presented with acute non-rotatory dizziness and disequilibrium. Neuro-ophthalmologic examination found impaired smooth pursuit and hypometric saccades in the contralesional direction, and disconjugate ipsiversive ocular torsion, but without spontaneous or gaze-evoked nystagmus. Imaging study showed an infarction restricted to the rostral end of right cerebellar vermis involving the lingual and central lobules. The anterior cerebellar vermis participates in the maintenance of axial posture and gait, and also in the control of ocular motor and vestibular systems.

The neural mechanisms of voluntary control of saccadic eye movements / 中华行为医学与脑科学杂志

Voluntary control of saccadic eye movements is a kind of saccades controlled by conscious and always used to investigate the brain areas related to saccades and ability of response inhibition and work memory.Researching the neural mechanisms of voluntary control of saccadic eye movements could provide a basis to study the advanced cognitive function of brain and facilitate to explore basic neural mechanisms of abnormal saccadic in brain disorders.As neuroimaging technologies develops,intensive studies about the neural mechanisms of voluntary control of saccadic eye movements have been made great progress.It is showed that several brain areas such as prefrontal cortex,subcortical areas and parietal cortex mainly in participate.These multiple brain regions are involved in voluntary control of saccadic eye movements at different stages.Antisaccades and memory-guided saccades including different brain regions because of their different characteristics of saccadic.The future direction of the research is to combine study with neural imaging technology,and to study more about the brain regions and their functional connectivity involved in voluntary control of saccadic eye movements.

Phase portrait analysis of eye movement waveforms in congenital nystagmus eyes / 中华实验眼科杂志

Background The characteristics of eye movement waveforms in congenital nystagmus eyes is so complicated that the time-series waveform can hardly demonstrate the oscillational kinetic property of the eye movement of nystagmus,which is not convenient for the clinical diagnosis and evaluation.The eye movement system is a nonlinear feedback control system,and phase portrait analysis is a useful method in describing the characteristics of movement in a nonlinear system.Objective This study was to establish the phase portrait analysis method of the eye movement waveforms in congenital nystagmus eyes and provide a new technique for the clinical diagnosis and evaluation of congenital nystagmus.Methods A prospective series-case observational study was performed.This study complied with the Declaration of Helsinki and was approved by Ethic Commission of Tianjin Eye Hospital.Written informed consent was obtained from each patient before examination.Twenty-five patients with congenital nystagmus were enrolled and received examination of video-oculography (VOG) in Tianjin Eye Hospital from April 2012 to February 2013,including 12 patients with congenital motor nystagmus (CMN) and 13 patients with latent nystagmus (LN).The VOG data were format-converted and processed by a Matlab routine.VOG-based phase portraits of eye movement cycles were drawn and related parameters were measured from the phase portraits for further analysis and comparison.Main measurement indexes were cycle position shift (CPS),slow phase peak velocity (SPV),standardized slow-phase peak (SSPV),fast phase peak velocity (FPV) and standardized fast-phase peak velocity (SFPV).Two principal types of waveforms,increasing-velocity type and decreasing-velocity type were compared.Results The phase portraits of the waveforms of congenital nystagmus were cycles of reciprocating trajectories.The slow phases were in dense ribbon region,and the fast phases were in sparse annular region,and all the trajectories travelled in clockwise.The CPS,SPV and FPV of increasing-velocity type were (4.646 ± 1.565),(223.821 ± 114.049),(767.481 ±263.560) ° per second,respectively.The CPS,SPV and FPV of decreasing-velocity type were (9.373 ±4.189),(357.531 ± 154.300) and (1 148.706 ±541.362) ° per second,respectively.The SPVs and FPVs of both increasing-velocity type and decreasing-velocity type showed strong correlation with CPS,respectively (the increasing-velocity type:rSPV-CPS =0.685,P=0.000;rFPV-CPS =0.680,P=0.000;the decreasing-velocity type rSPV-CPS =0.783,P =0.000;rFPV-CPS =0.803,P =0.000).FPVs were significantly larger than SPVs in both types of waveforms (t =6.558,P =0.000;t =5.068,P =0.000).The SSPV of increasing-velocity type was (48.062 ± 15.365) ° per second,which was slightly larger than (41.099± 17.027) ° per second of decreasing-velocity type,with no significant difference between them (t=1.070,P=0.296).The SFPV of increasing-velocity type was (171.186±47.825)° per second,which was larger than (125.317-±38.266)° per second of decreasing-velocity type,showing a significant difference between them (t =2.658,P =0.014).Conclusions Phase portraits can visualize the cyclically dynamic features of congenital nystagmus in a direct way.It facilitates the measurement of eye movement amplitude,speed and other parameters.The phase portrait analysis method provides a novel useful tool in the clinical diagnosis and treatment efficacy evaluation of congenital nystagmus.

Avaliação oculomotora em adultos: um estudo do efeito da idade e de alterações visuais / Oculomotor evaluation in adults: a study of the effect of age and visual alterations

RESUMO Objetivo Avaliar os movimentos oculares de sácadas, perseguição e o nistagmo optocinético em adultos, analisando o efeito da idade e das alterações visuais. Métodos Foram avaliados 40 sujeitos de ambos os gêneros, com faixa etária de 20 a 49 anos de idade, sem queixas auditivas ou vestibulares e que apresentaram avaliação audiológica básica dentro dos padrões da normalidade e ausência de nistagmo espontâneo de olhos abertos, nistagmo semi-espontâneo e nistagmo espontâneo de olhos fechados maior que 6º/s. Todos os participantes foram submetidos às provas de nistagmo espontâneo, nistagmo optocinético, movimentos sacádicos fixos, aleatórios e rastreio pendular, por meio da vectoeletronistagmografia computadorizada. Os achados foram analisados segundo as variáveis idade e presença de alteração visual, do tipo ametropias. Os resultados passaram por análise estatística descritiva e inferencial. Resultados Não houve diferença nas provas de nistagmo optocinético, sacádico fixo, aleatório e rastreio pendular, quando analisadas com relação à idade. Quanto à variável alteração visual, a preponderância direcional do nistagmo, observada na prova do nistagmo optocinético, foi maior em indivíduos com alterações visuais. Nos movimentos sacádicos aleatórios, também se observou diferença em relação à velocidade máxima, sendo maior em indivíduos sem alterações visuais. Conclusão As provas oculomotoras não sofreram influência do fator idade na faixa etária pesquisada, porém, a presença de alterações visuais exerceu influência em alguns dos parâmetros das provas oculomotoras.

ABSTRACT Purpose To evaluate saccadic and pursuit ocular movements and optokinetic nystagmus in adults, analyzing the effect of age and visual alterations. Methods We evaluated 40 subjects of both genders, aged 20-49 years, with no auditory or vestibular complaints and who presented a normal basic audiology evaluation, absence of spontaneous nystagmus with open eyes, semi-spontaneous nystagmus, and spontaneous nystagmus with eyes closed greater than 6º/s. All participants underwent the tests of spontaneous nystagmus, optokinetic nystagmus, fixed and random saccadic movements, and pendular tracking using computerized vectoelectronystagmography. The findings were analyzed according to age and visual changes (ametropias). The results underwent a descriptive and inferential analysis. Results There was no difference in the tests of optokinetic nystagmus, fixed and random saccadic movement, and pendular tracking when analyzed with regard to age. As for the variable presence of visual alteration, directional preponderance of nystagmus, observed in the optokinetic nystagmus test, was higher in individuals with visual alterations. In the random saccadic movement, there was also a difference in relation to the maximum velocity, which was higher in individuals with no visual alterations. Conclusion The oculomotor tests were not affected by the age factor in the studied age group, but the presence of visual alterations exerted influence on some of the parameters of the oculomotor tests.

Normative Data of Videonystagmography in Young Healthy Adults under 40 Years Old

PURPOSE: The purpose of this study was to establish a set of normative data values for saccade movements using videonystagmography and to evaluate the effects of manual correction on this data. METHODS: We examined 25 healthy subjects (9 men and 16 women). All tests were carried out by one well-instructed physician. Errors such as the wrong detection of the inflection point, missing movement, and prediction occurred during some tests. Thus, the same physician manually corrected the data by deleting error data from row results. RESULTS: We established a set of normative data for horizontal saccade movements (amplitude size 15 and 30 degrees) for mean peak velocity, latency, and accuracy. Manual correction only impacted latency and accuracy at 30 degrees horizontal, which is likely related to possible errors during the test. CONCLUSIONS: The present study provides clinically useful videonystagmography-based normative data for clinicians regarding saccade movements in Korean individuals.

Efectos de los movimientos sacádicos oculares en la estabilización de control postural / Efeitos dos movimentos sacádicos oculares na estabilização do controle postural / Effects of saccadic eye movements on postural control stabilization

Several structures of the central nervous system share involvement in both ocular and postural control, but the visual mechanisms in postural control are still unclear. There are discrepant evidences on whether saccades would improve or deteriorate stabilization of posture. The purpose of this study was to determine the influence of saccadic eye movements on postural control while standing in different basis of support. Twelve young adults stood upright in wide and narrow stances while performing fixation and saccades of low and high frequencies. Body sway was attenuated during saccades. Trunk anterior-posterior sway and trunk total displacement decreased during saccades compared to fixation; higher sway mean frequency in anterior-posterior direction during saccades was observed. Body sway was reduced in wide compared to narrow stance during high frequency saccades. These results indicate that eye movement improves postural stabilization and this effect is stronger in combination of wide stance-high frequency gaze condition.

Várias estruturas do sistema nervoso central compartilham envolvimento nos controles ocular e postural, mas os mecanismos visuais no controle postural ainda não estão claros. Existem evidências discrepantes sobre a possibilidade de movimentos sacádicos melhorarem ou deteriorarem a estabilização postural. O objetivo desse estudo foi determinar a influência de movimentos sacádicos dos olhos sobre o controle postural em diferentes bases de apoio. Doze adultos jovens ficaram em pé, mantendo a postura sobre base ampla e restrita enquanto realizavam fixações e movimentos sacádicos de baixa e alta frequência. Oscilação corporal foi atenuada durante movimentos sacádicos. A oscilação do tronco na direção ântero-posterior e o deslocamento total do tronco diminuíram durante movimentos sacádicos comparados à fixação; maior frequência média de oscilação na direção ântero-posterior durante movimentos sacádicos também foi observada. Oscilação corporal foi reduzida em postura com base ampla comparada à restrita durante movimentos sacádicos de alta frequência. Estes resultados indicam que o movimento do olho melhora a estabilização postural e este efeito é mais forte na condição que combina base ampla e alta frequência do olhar.

Varias estructuras del sistema nervioso central comparten de participación en los controles ocular y de postura. Existen pruebas dispares sobre lo movimiento sacádico mejorar o deteriorar la estabilización postural. El objetivo de este estudio fue determinar la influencia de los movimientos oculares sacádicos sobre el control postural en diferentes bases de apoyo. Doce jóvenes quedaram de pie manteniendo la postura de base amplia y restringido mientras hacian fijaciones y movimientos sacádicos de baja y alta frecuencia. Lal oscilación del cuerpo fue atenuada durante los movimientos sacádicos. La oscilación del tronco en dirección antero-posterior y el desplazamiento total del tronco han disminuido durante los movimientos sacádicos comparados con fijación; también se ha observado mayor frecuencia media de oscilación en la dirección anteroposterior durante los movimientos sacádicos. La oscilación del cuerpo se redujo por la postura de base amplia en comparación con la restringida durante los movimientos sacádicos de alta frecuencia. Estos resultados indican que lo movimiento de ojo mejora la estabilización postural y este efecto es más fuerte para la condición de base amplia y alta frecuencia de la mirada.

Cerebellar Control of Saccades / 대한임상신경생리학회지

Saccades are rapid eye movements that shift the line of sight between successive points of fixation. The cerebellum calibrates saccadic amplitude (dorsal vermis and fastigial nucleus) and the saccadic pulse-step match (flocculus) for optimal visuo-ocular motor behavior. Based on electrophysiology and the pharmacological inactivation studies, early activity in one fastigial nucleus could be important for accelerating the eyes at the beginning of a saccade, and the later activity in the other fastigial nucleus could be critical for stopping the eye on target, which is controlled by inhibitory projection from the dorsal vermis. The cerebellum could monitor a corollary discharge of the saccadic command and terminate the eye movement when it is calculated to be on target. The fastigial nucleus and dorsal vermis also participate in the adaptive control of saccadic accuracy.