Analysis of eye movement characteristics in newly diagnosed drug-naive Parkinson′s disease / 中华神经科杂志

Objective:To explore eye movement characteristics in newly diagnosed, drug-naive Parkinson′s disease (PD) patients and their correlation with motor and non-motor symptoms.Methods:Seventy-five newly diagnosed, drug-naive PD patients and 46 healthy controls (HCs) were included in this cross-sectional study. Patients were recruited from the Department of Neurology, Shanghai Ninth People′s Hospital, Shanghai Jiao Tong University School of Medicine from November 2017 to December 2021, while HCs were recruited from the local community during the same period. For PD patients, motor severity was measured with the modified Hoehn and Yahr stage, Movement Disorder Society Unified Parkinson′s Disease Rating Scale part Ⅲ and the Freezing of Gait questionnaire. Non-motor symptoms were evaluated by serial scales such as Non-Motor Symptoms Questionnaire, 16-item odor identification test from Sniffin Sticks, 17-item Hamilton Rating Scale for Depression, Chinese version of Mini-Mental State Examination, Montreal Cognitive Assessment Basic and REM Behavior Disorder Screening Questionnaire. All subjects underwent oculomotor test including pro-saccade task and smooth pursuit eye movement (SPEM) task in the horizontal direction via videonystagmography. Visually guided saccade latency, saccadic accuracy and gain in SPEM at three frequencies (0.1, 0.2, 0.4 Hz) of the horizontal axis were compared between the 2 groups. The association between key oculomotor parameters and clinical phenotypes was explored in PD patients. The receiver operating characteristic (ROC) analyses of eye movement parameters as independent factors were also performed for detecting PD from HCs, then combining the saccadic latency, saccadic accuracy and the most significant SPEM gain (0.4 Hz) as the model to distinguish PD from HCs.Results:Relative to HCs, newly diagnosed, drug-naive PD patients showed prolonged saccadic latency [(210.4±41.3) ms vs (191.3±18.9) ms, t=-3.445, P=0.001] and decreased saccadic accuracy (88.4%±6.8% vs 92.2%±6.1%, t=3.064, P=0.003). SPEM gain in PD was uniformly reduced at each frequency(0.1 Hz: 0.68±0.15 vs 0.74±0.14, t=2.261, P=0.026; 0.2 Hz: 0.72±0.16 vs 0.79±0.16, t=2.704, P=0.008; 0.4 Hz: 0.67±0.19 vs 0.78±0.19, t=2.937, P=0.004). The ROC analyses of saccade latency, saccadic accuracy and gain in SPEM at 0.1, 0.2, 0.4 Hz as independent factors for detecting PD from HCs showed that the area under the curve (AUC) of each parameter was lower than 0.7: the AUC of saccade latency was 0.641 ( P=0.010), the AUC of saccadic accuracy was 0.681 ( P=0.001), the AUC of gain in SPEM at 0.1 Hz was 0.616 ( P=0.032), at 0.2 Hz was 0.652 ( P=0.005), at 0.4 Hz was 0.660 ( P=0.003). Combining the saccadic latency, saccadic accuracy and the most significant SPEM gain (0.4 Hz) revealed that the model could significantly distinguish PD from HCs with an 80.4% sensitivity and a 73.3% specificity (AUC=0.780, P<0.001). Prolonged saccadic latency was correlated with long disease duration ( β=0.334, 95% CI 0.014-0.654, P=0.041), whereas decreased SPEM gain was associated with severe motor symptoms in newly diagnosed drug-naive PD patients (0.1 Hz: β=-0.004, 95% CI -0.008--0.001, P=0.036; 0.4 Hz: β=-0.006, 95% CI -0.011--0.001, P=0.012). Conclusions:Ocular movements are impaired in newly diagnosed, drug-naive PD patients. These changes could be indicators for disease progression in PD.

The Relationship between Saccades and Locomotion

Human locomotion involves a complex interplay among multiple brain regions and depends on constant feedback from the visual system. We summarize here the current understanding of the relationship among fixations, saccades, and gait as observed in studies sampling eye movements during locomotion, through a review of the literature and a synthesis of the relevant knowledge on the topic. A significant overlap in locomotor and saccadic neural circuitry exists that may support this relationship. Several animal studies have identified potential integration nodes between these overlapping circuitries. Behavioral studies that explored the relationship of saccadic and gait-related impairments in normal conditions and in various disease states are also discussed. Eye movements and locomotion share many underlying neural circuits, and further studies can leverage this interplay for diagnostic and therapeutic purposes.

Clinical Usefulness of Video Head Impulse Test-Comparison of Bithermal Caloric Test and Bedside Head Impulse Test / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Video head impulse test system (vHIT) is an easy-to-use test and there are numerous studies showing its efficacy. The aim of the study was to evaluate the clinical usefulness of vHIT as an initial test in determining vestibular hypofunction in patients with dizziness. SUBJECTS AND METHOD: The study recruited 103 outpatients who visited our ear clinic with dizziness. We performed both bedside head impulse test (bHIT), vHIT and bithermal caloric tests for 103 patients. Both bHIT and vHIT were consecutively performed in each subject on the same day by the same examiner. RESULTS: The sensitivity of bHIT and vHIT was determined based on the bithermal caloric test results, which showed that vHIT was more sensitive than bHIT. There was a significant negative correlation between vHIT gain and canal paresis (p < 0.05). Results of some patients indicated dissociation between vHIT and caloric test. CONCLUSION: T here is a significant correlation between the results of vHIT and caloric test. Although vHIT does not replace the caloric test, it would be useful to evaluate the initial vestibular loss in patients with dizziness.

Clinical analysis of three cases of ocular flutter-opsoclonus in adults / 中华神经科杂志

Objective Through an analysis of three cases of ocular flutter-opsoclonus in adults and a review of the relevant literature,we summarized its characteritics to improve the clinical awareness of this sign.Methods Three cases of adult-onset ocular flutter-opsoclonus from July 2014 to July 2017 were retrospectively analyzed in terms of clinical features,cerebrospinal fluid (CSF) analysis,brain imaging,etiologies and treatment,and followed up through telephone calls.Results Case 1:A 68-year-old man presented with ocular flutter,vertigo,myoclonus,ataxia and conscious disturbance.CSF analysis demonstrated pleocytosis and mildly elevated protein level.Brain MR imaging revealed ischemia,and SPECT showed hypoperfusion involving left frontal and occipital lobes.Paraneoplastic syndrome was considered as the etiology.The symptoms subsided without any specific treatment.He died from lung cancer within one year.Case 2:A 66-year-old man presented with ocular flutter,vertigo,ataxia,conscious disturbance and fever.CSF protein level was severely elevated.Brain MR imaging revealed ischemia.Epstein-Barr virus infection was considered as the etiology.The symptoms improved with the administration of antiviral drugs and steroid.Relapse was not observed in the two-year follow-up.Case 3:A 34-year-old woman presented with opsoclonus,oscillopsia,vertigo,ataxia,conscious disturbance and fever.MR imaging showed midbrain lesions.Viral brainstem encephalitis was considered as the etiology.The symptoms improved with the administration of antiviral drugs,steroid,intravenous immunoglobulin and clonazepam.Relapse was not observed in the two-year follow-up.Conclusions Infection and tumors are common etiologies of ocular flutter-opsoclonus.Treatment includes etiological management for infection or tumors and immunosuppressive therapy.The clinical outcomes vary with the underlying etiologies.

Decoding Saccadic Directions Using Epidural ECoG in Non-Human Primates

A brain-computer interface (BCI) can be used to restore some communication as an alternative interface for patients suffering from locked-in syndrome. However, most BCI systems are based on SSVEP, P300, or motor imagery, and a diversity of BCI protocols would be needed for various types of patients. In this paper, we trained the choice saccade (CS) task in 2 non-human primate monkeys and recorded the brain signal using an epidural electrocorticogram (eECoG) to predict eye movement direction. We successfully predicted the direction of the upcoming eye movement using a support vector machine (SVM) with the brain signals after the directional cue onset and before the saccade execution. The mean accuracies were 80% for 2 directions and 43% for 4 directions. We also quantified the spatial-spectro-temporal contribution ratio using SVM recursive feature elimination (RFE). The channels over the frontal eye field (FEF), supplementary eye field (SEF), and superior parietal lobule (SPL) area were dominantly used for classification. The α-band in the spectral domain and the time bins just after the directional cue onset and just before the saccadic execution were mainly useful for prediction. A saccade based BCI paradigm can be projected in the 2D space, and will hopefully provide an intuitive and convenient communication platform for users.

Clinical significance of saccade test, smooth pursuit test, and optokinetic nystagmus test in nystagmography / 영남의대학술지

BACKGROUND: Saccade test, smooth pursuit test, and optokinetic nystagmus test are clinically useful tests to accurately diagnose vertigo. However, there have only been a few studies regarding a correlation between the anatomical site of the lesion and the abnormality of eyeball movement in patients with vertigo. METHODS: The medical records of 97 patients with vertigo between January 2006 and June 2008 were reviewed retrospectively. We classified many kinds of abnormalities regarding the saccade test, smooth pursuit test and optokinetic nystagmus test into several categories and analyzed the localizing lesion of vertigo. RESULTS: According to the saccade test, both total saccade abnormality (S-total) and slow velocity of saccade (S-type 3) were shown to be significantly higher in the central lesion of vertigo. According to the smooth pursuit test, symmetrical unidirectional smooth pursuit abnormality (SP-type 2) was observed to be significantly higher in the peripheral lesion over vertigo. Moreover, according to the optokinetic nystagmus test, total optokinetic nystagmus abnormalities (OKN-total) were shown to be significantly useful findings in the diagnosis of the central lesion of vertigo. The coexisting abnormalities of all three tests (S+SP+OKN abnormalities) were shown to be significantly higher in the central lesion of vertigo. CONCLUSION: These results suggest that all these tests, saccade test, smooth pursuit test, and optokinetic nystagmus test, are very useful to distinguish between the central lesion and the peripheral lesion of vertigo. However, these tests are not beneficial in localizing the central lesion of vertigo.

Clinical significance of saccade test, smooth pursuit test, and optokinetic nystagmus test in nystagmography / 영남의대학술지

BACKGROUND: Saccade test, smooth pursuit test, and optokinetic nystagmus test are clinically useful tests to accurately diagnose vertigo. However, there have only been a few studies regarding a correlation between the anatomical site of the lesion and the abnormality of eyeball movement in patients with vertigo.METHODS: The medical records of 97 patients with vertigo between January 2006 and June 2008 were reviewed retrospectively. We classified many kinds of abnormalities regarding the saccade test, smooth pursuit test and optokinetic nystagmus test into several categories and analyzed the localizing lesion of vertigo.RESULTS: According to the saccade test, both total saccade abnormality (S-total) and slow velocity of saccade (S-type 3) were shown to be significantly higher in the central lesion of vertigo. According to the smooth pursuit test, symmetrical unidirectional smooth pursuit abnormality (SP-type 2) was observed to be significantly higher in the peripheral lesion over vertigo. Moreover, according to the optokinetic nystagmus test, total optokinetic nystagmus abnormalities (OKN-total) were shown to be significantly useful findings in the diagnosis of the central lesion of vertigo. The coexisting abnormalities of all three tests (S+SP+OKN abnormalities) were shown to be significantly higher in the central lesion of vertigo.CONCLUSION: These results suggest that all these tests, saccade test, smooth pursuit test, and optokinetic nystagmus test, are very useful to distinguish between the central lesion and the peripheral lesion of vertigo. However, these tests are not beneficial in localizing the central lesion of vertigo.

Causes of False Negative Bedside Head Impulse Test / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: The bedside head impulse test (bHIT) in bare eyes often overlooks possible vestibular losses by missing the corrective saccade. This is why it is necessary to compare bHIT against video head impulse test (vHIT), which is more accurate in identifying vestibular losses than the bedside test. SUBJECTS AND METHOD: A total of 51 vHIT positive ears underwent the study, and out of those, 47 were diagnosed with dizziness. bHIT and vHIT were performed for patients, and the occurrence rate of overt saccade (OS) was calculated. RESULTS: Among the 51 vHIT positive ears, 33 (64.7%) were bHIT positive ears and 18 ears (35.3%) were bHIT negative. Patterns of positive vHIT were classified as A: no corrective saccade, B: covert saccade (CS) only, C: OS only, and D: CS with OS (CS+OS), which were 45 out of 51 ears (88%). The occurrence rate of OS was higher in the bHIT positive group than in the bHIT negative group (p=0.05), and higher in the CS negative group (CS-) than in the CS positive group (CS+) (p<0.001). CONCLUSION: Possible causes of false negative results of bHIT are seen as following: the absence of corrective (covert and overt) saccade, the occurrence of CS only, and missing the OS during the bHIT (probably due to low occurrence rate of OS). The occurrence of CS should be considered as an important factor in false negative bHIT when lowering the occurrence rate of OS.

Saccadic Palsy after Cardiac Surgery: Serial Neuroimaging Findings during a 6-Year Follow-Up

BACKGROUND: Patients who develop horizontal and vertical saccadic palsy after cardiac surgery have rarely been described. Although most such patients exhibit distinct neurological deficits, their brain MRI findings are almost normal. In addition, functional neuroimaging of such patients has never been reported. CASE REPORT: A 43-year-old woman with dysarthria, dysphagia, and horizontal and vertical saccadic palsy after cardiac surgery was followed up for about 6 years; serial brain MRIs has been performed during this period, including susceptibility-weighted imaging (SWI) and [18F]-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET). Multiple microbleeds in the cerebral cortex, cerebellum, and brainstem, and glucose hypometabolism in the brainstem, cerebellum, and multiple cortical areas. CONCLUSIONS: To the best of our knowledge, this is the first reported case of saccadic palsy after cardiac surgery with serial SWI and [18F]-FDG-PET performed to explore the possible cerebral lesions.

Inhibitory control and the adolescent brain: a review of fMRI research

Adolescence is a developmental period frequently characterized by impulsive behavior and suboptimal decision making, aspects that often result in increased rates of substance abuse, unprotected sex, and several other harmful behaviors. Functional magnetic resonance imaging (fMRI) studies have attempted to reveal the brain mechanisms that underlie the typical inhibitory control limitations associated with this developmental period. In the present review, all available studies in the PsycINFO, PubMed, and Web of Science databases that investigated this issue utilizing fMRI were analyzed. In contrast to adults, adolescents exhibited decreased activity in several brain regions associated with inhibitory control such as the dorsolateral prefrontal cortex, anterior cingulate cortex, and fronto-striatal regions. The decreased activity found in these regions may underlie the diminished inhibitory control abilities associated with this development period.

Inhibitory deficits of oculomotor behavior in children with attention deficit hyperactivity disorder / 中国心理卫生杂志

Objective:To examine the characteristics of oculomotor inhibition about children with attention deficit hyperactivity disorder(ADHD).Methods:Twenty-one children with ADHD according to the Diagnostic and Statistical Manual of Mental Disorder,4th edition(DSM-IV) and 21 matched controls were administered with fixation,prosaccade and antisaccade tasks.Results:(1) In the fixation task,the children with ADHD demonstrated significantly more intrusive saccade errors than the controls in either condition with distractors or without distractors[no distractors:(12.67±12.28) vs.(6.38±6.95),P=0.040;distractors:(16.91±10.00) vs.(11.29±5.99),P=0.030].(2) In the prosaccade task,there were no significant differences found between groups in saccadic parameters,in either gap condition or overlap condition.(3) In antisaccade task,the direction error rates of the ADHD group in either gap condition or overlap condition,were both higher than that of the control group[gap:(68.14±17.85) % vs.(54.10±20.22) %,P=0.020;overlap:(62.49±17.54) % vs.(49.27±17.21) %,P=0.020].Conclusion: It suggests that there is an abnormality of the oculomotor inhibition,which may be caused by abnormal structure and/or function of fronto-striatal in ADHD children.

Alternation of Saccadic System in Patients with Parkinson's Disease(review) / 中国康复理论与实践

@#The saccadic movement of patients with Parkinson's disease was abnormal and might be related to the severity of the disease.The abnormal saccadic movement was not related to the symptoms of Parkinson's disease directly,the accesses of controlling limbs' and eyes' movement are comparatively independent.

Unilateral Parieto-Occipital Lobe Infarction Presenting with Optic Ataxia and Saccadic Abnormalties: A Case Report

Optic ataxia is characterized by an impaired visual control of the direction of arm reaching to a visual target, accompanied by defective hand orientation and grip formation. In humans, optic ataxia is associated with lesions of the superior parietal lobule, which also affect visually guided saccades and other forms of eye-hand coordination. A 67-year-old woman presented with sudden, unilateral, direct optic ataxia in the right homonymous half field and saccadic abnormalities which consisted of prolonged latency, undershoot dysmetria, and decreased velocity. Brain MRI showed a left parieto-occipital watershed infarction. It is suggested that lesions of the superior parietal lobule and the adjacent parietal eye field are responsible for optic ataxia and saccadic abnormalities, respectively.

Relationship between predictable ocular motor control and cognitive function in Parkinson's disease / 上海第二医科大学学报

Objective To explore the relationship between predictable ocular motor control and cognitive function in Parkinson's disease(PD). Methods Videonystagmography was used to examine 24 patients with idiopathic PD(PD group) and 24 healthy controls(control group) on predictable ocular motor control.The accuracies of saccade were compared between two groups.The correlation among accuracy for predictive saccade(latency

Clinical Significance of Saccade Abnormalities / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: The saccadic eye movement means rapid eye movement in order to fixate an intended target with fovea. Frontal lobe, brain stem and paramedian pontine reticular formation operate the saccade movement in the central nervous system. Although saccadic abnormalities were usually seen in the CNS lesion(most commonly in the cerebellar lesion) some normal individuals consistently undershoot or overshoot the target(corrective saccade). Because there are several possibilities for serious error when interpreting the saccade test, clinical usefulness of saccade test may be uncertain. We study the saccade movement in out dizzy patients to find out the definite usefulness of saccadic abnormality and cause of dizziness according to the saccadic abnormalities. MATERIAL AND METHOD: For 4 years, 1994.1.-1997.12, 53 patients showed saccade abnormalities and they were classified into 5 categories-undershoot, overshoot, slow velocity of saccade, impaired saccade and fail of saccade. Spontaneous nystagmus, gaze nystagmus, pursuit test and optokinetic test were also performed. We analyzed the cause of saccade abnormality and other associated eye movement disorders. RESULTS: Almost all saccade abnormalities were seen in central disease(71%), but some could be seen in specific cases of peripheral disease(11%) and in other conditions(18%). In peripheral lesion, only saccade undershoot was seen without other abnormal eye movement. In central lesion, all kinds of saccade movement were seen with or without other abnormal eye movement disorders, but there was no correlation between the sites of lesion and types of saccade. Spontaneous nystagmus was seen in 6 patients, but there was no correlation between the causes of vertigo and the types of saccade abnormality. CONCLUSION: Saccade test must be clinically useful for differentiating between the central and peripheral lesion using the types of saccade abnormality and other abnormal eye movement. But many factors that affect saccade movement should be considered when interpreting the test results.

Distribution of Serotonin-2 Receptor in the Superior Collicullus of the Adult Rat: A Radioarutographic Study

The superior colliculus is a laminated structure that consisted with superficial and deep layers in the roof of midbrain and the center of visual information and sensorimotor intergration. The deep layers of the mammalian superior colliculus are concerned with generation of eye movements. Serotonin is a neurotransmitter of the central nervous system and its binding sites can be classified into serotonin-1 receptor, serotonin-2 receptor and serotonin-3 receptor according to their pharmacological characteristics. The serotonin-2 receptors in the human brain presents in the motor cortex(area 4 of Brodmann) which role for the control of ocular motor activity and in the primary and secondary visual areas(areas 17 and 18 of Brodmann). Some of them presents in the limbic system role for the control of emotive activity, memory and other limbic functions. We performed this experiment to identify the anatomical distribution of the serotonergic nerve terminals in the superior colliculus of the rat by microscopicautography. It has been demonstrated that the serotonin-2 receptors of the superior colliculus are concerned with generation of saccade eye movements.

CLINICAL SIGNIFICANCE OF OCULOMOTOR CENTER TEST / 重庆医科大学学报

This paper reports oculomotor central tests on 25 normal subjects, 41 cases of peripharal'diseases.and 25 cases of centra) diseasses.All tets were normal in normal subjects.The tests were normal in peripheral diseases except that three cases of eye tracking test were type Ⅲ.Ocular saccade was abnormal in 10 cases (40%) , eye tracking test was typeⅢ-IV in 15 cases (60%) , and abnormality of optokinetic nystagmus was 80% in central diseases.A marked difference was found in ocular saccade, eye tracking and optokinetic nystagmus tests among three groups(P