The Experts below are selected from a list of 237 Experts worldwide ranked by ideXlab platform
Ji Soo Kim - One of the best experts on this subject based on the ideXlab platform.
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Rebound upbeat Nystagmus after lateral gaze in episodic ataxia type 2.
Cerebellum (London England), 2014Co-Authors: Hyo Jung Kim, Kwang-dong Choi, Ji Soo Kim, Jae-hwan Choi, Jin Hong Shin, David S. ZeeAbstract:Rebound Nystagmus is a transient Nystagmus that occurs on resuming the straight-ahead position after prolonged eccentric gaze. Even though rebound Nystagmus is commonly associated with gaze-evoked Nystagmus (GEN), development of rebound Nystagmus in a different plane of gaze has not been described. We report a patient with episodic ataxia type 2 who showed transient upbeat Nystagmus on resuming the straight-ahead position after sustained lateral gaze that had induced GEN and downbeat Nystagmus. The rebound upbeat Nystagmus may be ascribed to a shifting null in the vertical plane as a result of an adaptation to the downbeat Nystagmus that developed during lateral gaze.
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patterns of spontaneous and head shaking Nystagmus in cerebellar infarction imaging correlations
Brain, 2011Co-Authors: Young Eun Huh, Ji Soo KimAbstract:Horizontal head-shaking may induce Nystagmus in peripheral as well as central vestibular lesions. While the patterns and mechanism of head-shaking Nystagmus are well established in peripheral vestibulopathy, they require further exploration in central vestibular disorders. To define the characteristics and mechanism of head-shaking Nystagmus in central vestibulopathies, we investigated spontaneous Nystagmus and head-shaking Nystagmus in 72 patients with isolated cerebellar infarction. Spontaneous Nystagmus was observed in 28 (39%) patients, and was mostly ipsilesional when observed in unilateral infarction (15/18, 83%). Head-shaking Nystagmus developed in 37 (51%) patients, and the horizontal component of head-shaking Nystagmus was uniformly ipsilesional when induced in patients with unilateral infarction. Perverted head-shaking Nystagmus occurred in 23 (23/37, 62%) patients and was mostly downbeat (22/23, 96%). Lesion subtraction analyses revealed that damage to the uvula, nodulus and inferior tonsil was mostly responsible for generation of head-shaking Nystagmus in patients with unilateral posterior inferior cerebellar artery infarction. Ipsilesional head-shaking Nystagmus in patients with unilateral cerebellar infarction may be explained by unilateral disruption of uvulonodular inhibition over the velocity storage. Perverted (downbeat) head-shaking Nystagmus may be ascribed to impaired control over the spatial orientation of the angular vestibulo-ocular reflex due to uvulonodular lesions or a build-up of vertical vestibular asymmetry favouring upward bias due to lesions involving the inferior tonsil.
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reversal of initial positioning Nystagmus in benign paroxysmal positional vertigo involving the horizontal canal
Annals of the New York Academy of Sciences, 2009Co-Authors: Seung Han Lee, Myeongkyu Kim, Kihyun Cho, Ji Soo KimAbstract:In benign paroxysmal positional vertigo (BPPV), spontaneous reversal of the initial positioning Nystagmus rarely occurs without further position changes. We analyzed the characteristics of spontaneous reversal of the initial head-turning Nystagmus in 21 patients with BPPV involving the horizontal semicircular canal. All patients showed initial geotropic Nystagmus (first-phase Nystagmus) on head turning to either side while supine, which was followed by spontaneous reversal (second-phase Nystagmus). The reversal was either unilateral (n = 16) or bilateral (n = 5). The maximal slow phase velocity (SPV) and duration of the first-phase Nystagmus were greater and shorter than those of the second-phase Nystagmus. The reversal group showed greater maximal SPVs of the initial Nystagmus in either ipsi- or contralesional direction than the control group. BPPV resolved after particle repositioning maneuver (PRM) in most patients. However, one patient showed persistent apogeotropic Nystagmus after PRM. Short-term adaptation of the vestibulo-ocular reflex seems to be the main mechanism of spontaneous reversal of the initial positioning Nystagmus. However, coexistence of canalo- and cupulolithiasis should be considered in the patient showing bilateral spontaneous reversal.
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Nystagmus during neck flexion in the pitch plane in benign paroxysmal positional vertigo involving the horizontal canal
Journal of the Neurological Sciences, 2007Co-Authors: Seung Han Lee, Kwang-dong Choi, Seonghae Jeong, Ja Won Koo, Ji Soo KimAbstract:Abstract Background In benign paroxysmal positional vertigo involving the horizontal canal (HC-BPPV), Nystagmus may be induced by neck flexion in the pitch plane while sitting (head-bending Nystagmus). Objective To determine the characteristics and lateralizing value of head-bending Nystagmus in HC-BPPV. Methods Using video-oculography, head-bending Nystagmus was recorded in 54 patients with HC-BPPV (32 canalolithiasis and 22 cupulolithiasis). Lesion side was determined by comparing intensity of the Nystagmus induced by lateral head turning (head-turning Nystagmus) in supine. Results Head-bending Nystagmus was observed in 39 patients (72.2%) and lying-down Nystagmus in 41 (75.9%). Thirty three patients (61.1%) showed both types of Nystagmus while six (11.1%) had only head-bending and another eight (14.8%) showed only lying-down Nystagmus. In 45 patients with asymmetrical head-turning Nystagmus, the direction of head-bending Nystagmus was mostly toward the affected ear in canalolithasis (88.9%) and toward the intact ear in cupulolithasis (80.0%). In 9 (16.7%) patients whose affected ear could not be determined due to symmetrical head-turning Nystagmus, the particle repositioning maneuver based on the direction of head-bending or lying-down Nystagmus resulted in the resolution of symptom. Two patients showed a transition from canalo- to cupulolithiasis during head-bending posture. Conclusion In HC-BPPV, neck flexion in the pitch plane while sitting may generate Nystagmus by inducing ampullopetal migration of the otolithic debris in the horizontal canal or by ampullofugal deflection of the cupula by the attached otolithic debris. Head-bending Nystagmus may be a valuable sign for lateralizing the involved canal in HC-BPPV, especially when patients show symmetrical head-turning Nystagmus. Conversion of canalo- into cupulolithiasis by the neck flexion supports the current explanation of the mechanisms of HC-BPPV.
Chao Wen - One of the best experts on this subject based on the ideXlab platform.
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A Show of Ewald's Law: I Horizontal Semicircular Canal Benign Paroxysmal Positional Vertigo
Frontiers in neurology, 2021Co-Authors: X Zhang, Taisheng Chen, Wei Wang, Qiang Liu, Xi Han, Yanru Bai, Chao WenAbstract:Objective: To evaluate horizontal semicircular canal (HSC) effects according to Ewald's law and Nystagmus characteristics of horizontal semicircular canal benign paroxysmal positional vertigo (HSC-BPPV) in the supine roll test. Methods: Patients with HSC-BPPV (n = 72) and healthy subjects (n = 38) were enrolled. Latency, duration, and intensity of Nystagmus elicited by supine roll test were recorded using video nystagmography. Results: In patients with HSC-BPPV, horizontal Nystagmus could be elicited by right/left head position (positional Nystagmus) and during head-turning (head-turning Nystagmus), and Nystagmus direction was the same as that of head turning. Mean intensity values of head-turning Nystagmus in HSC-BPPV patients were (44.70 ± 18.24)°/s and (44.65 ± 19.27)°/s on the affected and unaffected sides, respectively, which was not a significant difference (p = 0.980), while those for positional Nystagmus were (40.81 ± 25.56)°/s and (17.69 ± 9.31)°/s (ratio, 2.59 ± 1.98:1), respectively, representing a significant difference (p < 0.0001). There was no positional Nystagmus in 49 HSC-BPPV patients after repositioning treatment, nor in the 38 healthy subjects. No significant difference in head-turning Nystagmus was detected in HSC-BPPV patients with or without repositioning. Conclusions: The direction and intensity of Nystagmus elicited by supine roll test in patients with HSC-BPPV, was broadly consistent with the physiological Nystagmus associated with a same HSC with single factor stimulus. Our findings suggest that HSC-BPPV can be a show of Ewald's law in human body.
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objective characteristics of Nystagmus in patients with posterior semicircular canal benign paroxysmal positional vertigo
Chinese journal of otorhinolaryngology head and neck surgery, 2019Co-Authors: Taisheng Chen, Wei Wang, Qiang Liu, Chao Wen, Xi Han, Peng LinAbstract:Objective To analyze and discuss the parameters and clinical significance of Nystagmus in patients with benign positional paroxysmal vertigo (BPPV) of posterior semicircular canal. Methods The subjects of the study were 564 BPPV patients diagnosed with posterior semicircular canal canalithis (PSC-can) from January 2016 to July 2017 in Tianjin No.1 Central Hospital, including 186 males and 378 females, with a median age of 57 years. The induced Nystagmus in Dix-Hallpike test was recorded by video nystagmuo graph(VNG), and the direction, latency, duration time and intensity characteristics of Nystagmus were compared with the position of hanging and sitting.SPSS17.0 software was used for statistical analysis. Results Vertical torsional Nystagmus was both induced with the position of hanging and sitting during Dix-Hallpike test. The vertical direction of the induced Nystagmus was upward and downward respectively. The latency, duration time and intensity of lesion side were L(2.65±1.92; 1.44±1.24), D(14.90±10.46; 15.28±8.06), and P(29.75±21.26; 14.08±9.48). The latency and intensity in hanging position were higher than those of sitting. The intensity rate was about 2∶1, with statistically significant difference (t=13.831, and 17.296, P all 0.05). Conclusions The Nystagmus intensity rate in Dix-Hallpike test between hanging and sitting position of lesion side in PSC-Can is 2∶1, which conforms to the Ewald′s law. The direction, latency and intensity of Nystagmus can be used as a reference index for the localization diagnosis of PSC-Canotolith. Key words: Benign paroxysmal positional vertigo; Semicircular canal; Nystagmus; Physiology
Irene Gottlob - One of the best experts on this subject based on the ideXlab platform.
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Nystagmus in Childhood
Pediatrics and neonatology, 2014Co-Authors: Eleni Papageorgiou, Rebecca J. Mclean, Irene GottlobAbstract:Nystagmus is an involuntary rhythmic oscillation of the eyes, which leads to reduced visual acuity due to the excessive motion of images on the retina. Nystagmus can be grouped into infantile Nystagmus (IN), which usually appears in the first 3-6 months of life, and acquired Nystagmus (AN), which appears later. IN can be idiopathic or associated to albinism, retinal disease, low vision, or visual deprivation in early life, for example due to congenital cataracts, optic nerve hypoplasia, and retinal dystrophies, or it can be part of neurological syndromes and neurologic diseases. It is important to differentiate between infantile and acquired Nystagmus. This can be achieved by considering not only the time of onset of the Nystagmus, but also the waveform characteristics of the Nystagmus. Neurological disease should be suspected when the Nystagmus is asymmetrical or unilateral. Electrophysiology, laboratory tests, neurological, and imaging work-up may be necessary, in order to exclude any underlying ocular or systemic pathology in a child with Nystagmus. Furthermore, the recent introduction of hand-held spectral domain optical coherence tomography (HH SD-OCT) provides detailed assessment of foveal structure in several pediatric eye conditions associated with Nystagmus and it can been used to determine the underlying cause of infantile Nystagmus. Additionally, the development of novel methods to record eye movements can help to obtain more detailed information and assist the diagnosis. Recent advances in the field of genetics have identified the FRMD7 gene as the major cause of hereditary X-linked Nystagmus, which will possibly guide research towards gene therapy in the future. Treatment options for Nystagmus involve pharmacological and surgical interventions. Clinically proven pharmacological treatments for Nystagmus, such as gabapentin and memantine, are now beginning to emerge. In cases of obvious head posture, eye muscle surgery can be performed to shift the null zone of the Nystagmus into the primary position, and also to alleviate neck problems that can arise due to an abnormal head posture.
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Aetiology of infantile Nystagmus.
Current opinion in neurology, 2014Co-Authors: Irene Gottlob, Frank A ProudlockAbstract:PURPOSE OF REVIEW Mechanisms underlying infantile Nystagmus are unclear. The aim of this review is to outline recent developments in understanding the aetiology of infantile Nystagmus. RECENT FINDINGS There have been advances in understanding mechanisms underlying idiopathic infantile Nystagmus, which has progressed through determining the role of the FRMD7 gene in controlling neurite outgrowth, and albinism, in which recent models have investigated the possibility of retinal miswiring leading to Nystagmus. We also briefly review aetiology of infantile Nystagmus in afferent visual deficits caused by ocular disease, and PAX6 mutations. Improved phenotypical characterization of all these infantile Nystagmus subtypes has been achieved recently through high-resolution retinal imaging using optical coherence tomography. Several new hypotheses proposing common mechanisms that could underlie various infantile Nystagmus subtypes are also highlighted. SUMMARY Although there is still no consensus of opinion regarding the mechanisms causing infantile Nystagmus, identification of new genes and determining their cellular function, phenotypical characterization of genetic subtypes, and improvements in animal models have significantly advanced our understanding of infantile Nystagmus. These recent developments pave the way to achieving a much clearer picture of infantile Nystagmus aetiology in the future.
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What We Know about the Generation of Nystagmus and Other Ocular Oscillations: Are We Closer to Identifying Therapeutic Targets?
Current Neurology and Neuroscience Reports, 2012Co-Authors: Rebecca Jane Mclean, Irene Gottlob, Frank Antony ProudlockAbstract:Mechanisms underlying acquired Nystagmus are better understood than those leading to infantile Nystagmus. Accordingly, further progress has been made in the development of effective therapies for acquired Nystagmus, mainly through pharmacological interventions. Some of these therapies have been developed under the guidance of findings from experimental animal models. Although mechanisms behind infantile Nystagmus are less understood, progress has been made in determining the genetic basis of Nystagmus and characterizing associated sensory deficits. Pharmacological, surgical, and other treatments options for infantile Nystagmus are now emerging. Further investigations are required for all forms of Nystagmus to produce high-quality evidence, such as randomized controlled trials, upon which clinicians can make appropriate treatment decisions.
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The pharmacological treatment of Nystagmus: a review.
Expert opinion on pharmacotherapy, 2009Co-Authors: Rebecca J. Mclean, Irene GottlobAbstract:Nystagmus is an involuntary, to-and-fro movement of the eyes that can result in a reduction in visual acuity and oscillopsia. Mechanisms that cause Nystagmus are better understood in some forms, such as acquired periodic alternating Nystagmus, than in others, for example acquired pendular Nystagmus, for which there is limited knowledge. Effective pharmacological treatment exists to reduce Nystagmus, particularly in acquired Nystagmus and, more recently, infantile Nystagmus. However, as there are very few randomized controlled trials in the area, most pharmacological treatment options in Nystagmus remain empirical.
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the effects of gabapentin and memantine in acquired and congenital Nystagmus a retrospective study
British Journal of Ophthalmology, 2006Co-Authors: Thomas Shery, Rebecca J. Mclean, Frank A Proudlock, N Sarvananthan, Irene GottlobAbstract:Background: Pharmacological treatment has been successful in some forms of acquired neurological Nystagmus. However, drugs are not known to be effective in idiopathic infantile Nystagmus or Nystagmus associated with ocular diseases. Methods: The authors retrospectively analysed Snellen visual acuity (VA), subjective visual function, and eye movement recordings of 23 patients with Nystagmus (13 secondary to multiple sclerosis, three associated with other neurological diseases, two idiopathic infantile, and five with associated ocular diseases) treated with gabapentin or memantine. Results: With gabapentin, 10 of 13 patients with Nystagmus secondary to multiple sclerosis (MS) showed some improvement. Memantine improved the VA in all three patients with MS who did not improve on gabapentin. There was no change of Nystagmus in other neurological disorders. Patients with congenital Nystagmus showed reduction of Nystagmus and their VA changes depended on the ocular pathology. Conclusion: Gabapentin and memantine may be effective in acquired Nystagmus secondary to MS. To the authors’ knowledge this is the first series of patients showing that gabapentin is effective in improving Nystagmus in congenital Nystagmus/Nystagmus associated with ocular pathology. Memantine may be useful as an alternative drug in treating patients with Nystagmus.
Hui Jong Oh - One of the best experts on this subject based on the ideXlab platform.
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Predicting a successful treatment in posterior canal benign paroxysmal positional vertigo.
Neurology, 2007Co-Authors: Hui Jong OhAbstract:Objective: To elucidate the characteristics and prognostic value of positioning Nystagmus during the second position of the Epley maneuver (90° contralateral head turn from the initial Hallpike maneuver). Method: The Epley maneuver was performed in 126 patients with confirmed posterior canal benign paroxysmal positional vertigo (PC-BPPV). The characteristics of positioning Nystagmus were investigated using video Frenzel goggles. Results: During the second position, 99 patients developed torsional upbeating Nystagmus, which was in the same direction (orthotropic Nystagmus) as during the first position (Hallpike maneuver), whereas 15 patients showed a reversed pattern. In 12 patents, Nystagmus was not induced during the second position. All 99 patients with orthotropic Nystagmus had resolution of BPPV after the first or second trial of the Epley maneuver. In contrast, 12 of the 15 patients with reversed Nystagmus and 8 of the 12 patients without Nystagmus failed to resolve. Conclusion: During the second position of the Epley maneuver, an orthotropic pattern of Nystagmus predicts a successful repositioning, whereas reversed Nystagmus or no Nystagmus is suggestive of poor response to repositioning.
Taisheng Chen - One of the best experts on this subject based on the ideXlab platform.
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A Show of Ewald's Law: I Horizontal Semicircular Canal Benign Paroxysmal Positional Vertigo
Frontiers in neurology, 2021Co-Authors: X Zhang, Taisheng Chen, Wei Wang, Qiang Liu, Xi Han, Yanru Bai, Chao WenAbstract:Objective: To evaluate horizontal semicircular canal (HSC) effects according to Ewald's law and Nystagmus characteristics of horizontal semicircular canal benign paroxysmal positional vertigo (HSC-BPPV) in the supine roll test. Methods: Patients with HSC-BPPV (n = 72) and healthy subjects (n = 38) were enrolled. Latency, duration, and intensity of Nystagmus elicited by supine roll test were recorded using video nystagmography. Results: In patients with HSC-BPPV, horizontal Nystagmus could be elicited by right/left head position (positional Nystagmus) and during head-turning (head-turning Nystagmus), and Nystagmus direction was the same as that of head turning. Mean intensity values of head-turning Nystagmus in HSC-BPPV patients were (44.70 ± 18.24)°/s and (44.65 ± 19.27)°/s on the affected and unaffected sides, respectively, which was not a significant difference (p = 0.980), while those for positional Nystagmus were (40.81 ± 25.56)°/s and (17.69 ± 9.31)°/s (ratio, 2.59 ± 1.98:1), respectively, representing a significant difference (p < 0.0001). There was no positional Nystagmus in 49 HSC-BPPV patients after repositioning treatment, nor in the 38 healthy subjects. No significant difference in head-turning Nystagmus was detected in HSC-BPPV patients with or without repositioning. Conclusions: The direction and intensity of Nystagmus elicited by supine roll test in patients with HSC-BPPV, was broadly consistent with the physiological Nystagmus associated with a same HSC with single factor stimulus. Our findings suggest that HSC-BPPV can be a show of Ewald's law in human body.
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objective characteristics of Nystagmus in patients with posterior semicircular canal benign paroxysmal positional vertigo
Chinese journal of otorhinolaryngology head and neck surgery, 2019Co-Authors: Taisheng Chen, Wei Wang, Qiang Liu, Chao Wen, Xi Han, Peng LinAbstract:Objective To analyze and discuss the parameters and clinical significance of Nystagmus in patients with benign positional paroxysmal vertigo (BPPV) of posterior semicircular canal. Methods The subjects of the study were 564 BPPV patients diagnosed with posterior semicircular canal canalithis (PSC-can) from January 2016 to July 2017 in Tianjin No.1 Central Hospital, including 186 males and 378 females, with a median age of 57 years. The induced Nystagmus in Dix-Hallpike test was recorded by video nystagmuo graph(VNG), and the direction, latency, duration time and intensity characteristics of Nystagmus were compared with the position of hanging and sitting.SPSS17.0 software was used for statistical analysis. Results Vertical torsional Nystagmus was both induced with the position of hanging and sitting during Dix-Hallpike test. The vertical direction of the induced Nystagmus was upward and downward respectively. The latency, duration time and intensity of lesion side were L(2.65±1.92; 1.44±1.24), D(14.90±10.46; 15.28±8.06), and P(29.75±21.26; 14.08±9.48). The latency and intensity in hanging position were higher than those of sitting. The intensity rate was about 2∶1, with statistically significant difference (t=13.831, and 17.296, P all 0.05). Conclusions The Nystagmus intensity rate in Dix-Hallpike test between hanging and sitting position of lesion side in PSC-Can is 2∶1, which conforms to the Ewald′s law. The direction, latency and intensity of Nystagmus can be used as a reference index for the localization diagnosis of PSC-Canotolith. Key words: Benign paroxysmal positional vertigo; Semicircular canal; Nystagmus; Physiology
