Benign paroxysmal positional vertigo(BPPV)represents the most common form of positional vertigo.It is caused by dislodged otoconia that freely float in the semicircular canals(canalolithiasis)or attach to the cupula(c...Benign paroxysmal positional vertigo(BPPV)represents the most common form of positional vertigo.It is caused by dislodged otoconia that freely float in the semicircular canals(canalolithiasis)or attach to the cupula(cupulolithiasis).A cupulolithiasis-type(or a heavy cupula-type)of BPPV implicating the lateral semicircular canal(LSCC)exhibits persistent ageotropic direction-changing positional nystagmus(DCPN)in a head-roll test.However,in some cases,unlike any type of BPPV,persistent geotropic DCPN cannot be explained by any mechanisms of BPPV,and don’t fit the current classifications.Recently,the notion of light cupula has been introduced to refer to the persistent geotropic DCPN.In this study,we looked at the clinical features of light cuplula and discussed the possible mechanisms and therapeutic strategies of the condition.The notion of light cupula is a helpful addition to the theory of peripheral positional vertigo and nystagmus.展开更多
Background:Vestibular symptoms on sitting-up are frequent on patients seen by vestibular specialists.Recently,a benign paroxysmal positional vertigo(BPPV)variant which elicits vestibular symptoms with oculomotor evide...Background:Vestibular symptoms on sitting-up are frequent on patients seen by vestibular specialists.Recently,a benign paroxysmal positional vertigo(BPPV)variant which elicits vestibular symptoms with oculomotor evidence of posterior semicircular canal(P-SCC)cupula stimulation on sitting-up was described and named sitting-up vertigo BPPV.A periampullar restricted P-SCC canalolithiasis was proposed as a causal mechanism.Objective:To describe new mechanisms of action for the sitting-up vertigo BPPV variant.Methods:Eighteen patients with sitting-up vertigo BPPV were examined with a pre-established set of positional maneuvers and follow-up until they resolved their symptoms and clinical findings.Results:All patients showed up-beating torsional nystagmus(UBTN)and vestibular symptoms on coming up from either Dix-Hallpike(DHM)or straight head-hanging maneuver.Sixteen out of 18 patients presented a sustained UBTN with an ipsitorsional component to the tested side on half-Hallpike maneuver(HH).A slower persistent contratorsional down-beating nystagmus was found in eleven out18 patients tested on nose down position(ND).Conclusions:Persistent direction changing positional nystagmus on HH and ND positions indicative of PSCC heavy cupula was found in 11 patients.A sustained UBTN on HH with the absence of findings on ND,which is suggestive of the presence of P-SCC short arm canalolithiasis,was found on 5 patients.All patients were treated with canalith repositioning maneuvers without success,but they resolved their findings by means of Brandt-Daroff exercises.We propose P-SCC heavy cupula and P-SCC short arm canalolithiasis as two new putative mechanisms for the sitting-up vertigo BPPV variant.展开更多
Report of childhood positional vertigo is very rare. We present a 7-year-old boy who revealed persistent direction-changing geotropic positional nystagmus. In the supine position, horizontal nystagmus toward the left ...Report of childhood positional vertigo is very rare. We present a 7-year-old boy who revealed persistent direction-changing geotropic positional nystagmus. In the supine position, horizontal nystagmus toward the left continued as long as the position was maintained. However, it ceased when the head was turned to the right side by 45°. With greater head turn (right-ear-down), nystagmus toward the right lasted for more than 1 minute. In the left-ear-down position, horizontal nystagmus toward the left occurred and lasted for more than 1 minute. After the disappearance of positional nystagmus, we detected canal paresis of the right ear by caloric test. We considered that the pathophysiology of the persistent type of geotropic nystagmus is a result of light debris cupulolithiasis of the horizontal canal.展开更多
The semicircular canals, composed of lateral, anterior and posterior canals in the inner ear, are the sensors of equilibrium during head rotation movements in the three-dimensional space. Semicircular canals are fille...The semicircular canals, composed of lateral, anterior and posterior canals in the inner ear, are the sensors of equilibrium during head rotation movements in the three-dimensional space. Semicircular canals are filled with endolymph confined by the cupula. The study of the relationship between endolymph flow and cupular deformation is important in revealing the semicircular canals biomechanical behavior. To date, there are few studies focusing on the transient endolymph flow and cupular deformation in response to a head rotation motion. The lateral semicircular canal is mainly responsible for the sense of the horizontal rotation movement. In order to figure out the intricate dynamics in the lateral semicircular canal during the head rotation motion, the time evolutions of both endolymph flow and cupular deformation are analyzed in this article by using a fully coupled fluid-structure interaction model. It is shown that the cupular deformation provides cues for understanding the physiology of sensing the head rotation.展开更多
Objective:This study aims to analyze the clinical characteristics of persistent geotropic and apogeotropic positional nystagmus of LC-BPPV in view of light and heavy cupula discussion.Material and method:The study gro...Objective:This study aims to analyze the clinical characteristics of persistent geotropic and apogeotropic positional nystagmus of LC-BPPV in view of light and heavy cupula discussion.Material and method:The study group includes 184 patients with LC BPPV(98 apogeotropic,86 geotropic type)who have been examined between 2009 and 2020.Ninety-nine females and 85 males,aged between 16 and 92 years were included(Ageotropic 49.32±14.12,geotropic 44.49±13.90 years).Average slow phase velocity(SPV)of positional nystagmus was documented and those with persistent directionchanging positional nystagmus lasting more than a minute were grouped separately.Age,gender difference,side of involvement,and recurrence pattern were particularly reviewed.Chi-square and One way ANOVA tests were used to compare the difference between groups.Statistical significance was set at P<0.05.Results:Thirty-seven patients with apogeotropic nystagmus(30.7%;37/98)and 18 patients with geotropic nystagmus(20.9%;18/86)had persistent nystagmus(p?0.05).Comparison of slow phase velocity(SPV)of persistent and non-persistent geotropic and apogeotropic positional nystagmus of the affected side was significant(p?0.05).Comparison of average age,male to female ratio,side of involvement,and the recurrence rate in patients with persistent and non-persistent geotropic and apogeotropic type positional nystagmus groups were not significant(p=0.177,p=0.521,p=0.891,p=0.702).Conclusion:Persistent geotropic and apogeotropic positional nystagmus is mostly correlated with the size,amount,and position of otoconial debris.It is difficult to justify the light cupula as a new geotropic variant of cupular pathology.Patients with persistent positional nystagmus present similar therapeutic outcomes and recurrence rates.展开更多
A three-dimensional numerical model of the membranous labyrinth of the semicircular canal of the inner ear was established to investigate the effects of canalithiasis of BPPV on the balance function of the inner ear.T...A three-dimensional numerical model of the membranous labyrinth of the semicircular canal of the inner ear was established to investigate the effects of canalithiasis of BPPV on the balance function of the inner ear.The movement of otolith particles in the membranous labyrinth was simulated when a person turns his head to a specific position.The effects of otolith movements on the balance function of the inner ear were simulated for different numbers,diameters,and initial positions of otoliths.The simulation results show that the otolith diameter affects the movement duration of otoliths in the membranous labyrinth.The number and diameter of otoliths,the diameter of the membranous labyrinth,and the initial position of the otoliths can cause changes in the pressure difference on both sides of the cupula of the crista ampullaris(cupula).The latent period and onset period are related to the diameter of otolith particles and the position of the head.There is also a correlation between the severity of the disease and the diameter and number of otolith particles.展开更多
This study was conducted to clarify the distribution and morphology of free neuromasts during the development of half-smooth tongue sole （Cynoglossus semilaevis） using scanning electron microscopy. During developmen...This study was conducted to clarify the distribution and morphology of free neuromasts during the development of half-smooth tongue sole （Cynoglossus semilaevis） using scanning electron microscopy. During development, （1） the apical surface of free neuromasts changed in shape from a circle to a four-poiut star; （2） the external structure changed from being level with the epidermis to papilla-like above the level of the epidermis; （3） the neuromast cupula changed from cylindrical to blade-shaped; （4） the free neuromasts went from occurring singly to being in clusters of a few single organs; （5） the arrangement changed from a linear array to no discernable pattern; （6） there was a significant increase in the number of free neuromasts after metamorphosis. In adult C. semilaevis, free neuromasts were only observed on the abocular side of the head. Thus, there were more free neuromasts located on the abocular side of the head with a higher concentration around the anterior nostril and mouth, which may have a mechanical sensory function to help locate food as an adaptation to a benthic mode of life.展开更多
基金The study was supported by the National Twelfth-Five Year Research Program of China(No.2012BAI12B02)the National Natural Science Foundation of China(No.81873701).
文摘Benign paroxysmal positional vertigo(BPPV)represents the most common form of positional vertigo.It is caused by dislodged otoconia that freely float in the semicircular canals(canalolithiasis)or attach to the cupula(cupulolithiasis).A cupulolithiasis-type(or a heavy cupula-type)of BPPV implicating the lateral semicircular canal(LSCC)exhibits persistent ageotropic direction-changing positional nystagmus(DCPN)in a head-roll test.However,in some cases,unlike any type of BPPV,persistent geotropic DCPN cannot be explained by any mechanisms of BPPV,and don’t fit the current classifications.Recently,the notion of light cupula has been introduced to refer to the persistent geotropic DCPN.In this study,we looked at the clinical features of light cuplula and discussed the possible mechanisms and therapeutic strategies of the condition.The notion of light cupula is a helpful addition to the theory of peripheral positional vertigo and nystagmus.
文摘Background:Vestibular symptoms on sitting-up are frequent on patients seen by vestibular specialists.Recently,a benign paroxysmal positional vertigo(BPPV)variant which elicits vestibular symptoms with oculomotor evidence of posterior semicircular canal(P-SCC)cupula stimulation on sitting-up was described and named sitting-up vertigo BPPV.A periampullar restricted P-SCC canalolithiasis was proposed as a causal mechanism.Objective:To describe new mechanisms of action for the sitting-up vertigo BPPV variant.Methods:Eighteen patients with sitting-up vertigo BPPV were examined with a pre-established set of positional maneuvers and follow-up until they resolved their symptoms and clinical findings.Results:All patients showed up-beating torsional nystagmus(UBTN)and vestibular symptoms on coming up from either Dix-Hallpike(DHM)or straight head-hanging maneuver.Sixteen out of 18 patients presented a sustained UBTN with an ipsitorsional component to the tested side on half-Hallpike maneuver(HH).A slower persistent contratorsional down-beating nystagmus was found in eleven out18 patients tested on nose down position(ND).Conclusions:Persistent direction changing positional nystagmus on HH and ND positions indicative of PSCC heavy cupula was found in 11 patients.A sustained UBTN on HH with the absence of findings on ND,which is suggestive of the presence of P-SCC short arm canalolithiasis,was found on 5 patients.All patients were treated with canalith repositioning maneuvers without success,but they resolved their findings by means of Brandt-Daroff exercises.We propose P-SCC heavy cupula and P-SCC short arm canalolithiasis as two new putative mechanisms for the sitting-up vertigo BPPV variant.
文摘Report of childhood positional vertigo is very rare. We present a 7-year-old boy who revealed persistent direction-changing geotropic positional nystagmus. In the supine position, horizontal nystagmus toward the left continued as long as the position was maintained. However, it ceased when the head was turned to the right side by 45°. With greater head turn (right-ear-down), nystagmus toward the right lasted for more than 1 minute. In the left-ear-down position, horizontal nystagmus toward the left occurred and lasted for more than 1 minute. After the disappearance of positional nystagmus, we detected canal paresis of the right ear by caloric test. We considered that the pathophysiology of the persistent type of geotropic nystagmus is a result of light debris cupulolithiasis of the horizontal canal.
基金supported by the National Natural Science Foundation of China (Grant No. 30971528)the Shanghai Committee of Science and Technology of China (Grant No.10ZR1403500)supported by the Graduate Innovation Fund of Fudan University (Grant No.EYH2126023)
文摘The semicircular canals, composed of lateral, anterior and posterior canals in the inner ear, are the sensors of equilibrium during head rotation movements in the three-dimensional space. Semicircular canals are filled with endolymph confined by the cupula. The study of the relationship between endolymph flow and cupular deformation is important in revealing the semicircular canals biomechanical behavior. To date, there are few studies focusing on the transient endolymph flow and cupular deformation in response to a head rotation motion. The lateral semicircular canal is mainly responsible for the sense of the horizontal rotation movement. In order to figure out the intricate dynamics in the lateral semicircular canal during the head rotation motion, the time evolutions of both endolymph flow and cupular deformation are analyzed in this article by using a fully coupled fluid-structure interaction model. It is shown that the cupular deformation provides cues for understanding the physiology of sensing the head rotation.
文摘Objective:This study aims to analyze the clinical characteristics of persistent geotropic and apogeotropic positional nystagmus of LC-BPPV in view of light and heavy cupula discussion.Material and method:The study group includes 184 patients with LC BPPV(98 apogeotropic,86 geotropic type)who have been examined between 2009 and 2020.Ninety-nine females and 85 males,aged between 16 and 92 years were included(Ageotropic 49.32±14.12,geotropic 44.49±13.90 years).Average slow phase velocity(SPV)of positional nystagmus was documented and those with persistent directionchanging positional nystagmus lasting more than a minute were grouped separately.Age,gender difference,side of involvement,and recurrence pattern were particularly reviewed.Chi-square and One way ANOVA tests were used to compare the difference between groups.Statistical significance was set at P<0.05.Results:Thirty-seven patients with apogeotropic nystagmus(30.7%;37/98)and 18 patients with geotropic nystagmus(20.9%;18/86)had persistent nystagmus(p?0.05).Comparison of slow phase velocity(SPV)of persistent and non-persistent geotropic and apogeotropic positional nystagmus of the affected side was significant(p?0.05).Comparison of average age,male to female ratio,side of involvement,and the recurrence rate in patients with persistent and non-persistent geotropic and apogeotropic type positional nystagmus groups were not significant(p=0.177,p=0.521,p=0.891,p=0.702).Conclusion:Persistent geotropic and apogeotropic positional nystagmus is mostly correlated with the size,amount,and position of otoconial debris.It is difficult to justify the light cupula as a new geotropic variant of cupular pathology.Patients with persistent positional nystagmus present similar therapeutic outcomes and recurrence rates.
基金This study was founded by the National Nature Science Foundation of China(11572079,11772087,31500765,11472074,11372069)。
文摘A three-dimensional numerical model of the membranous labyrinth of the semicircular canal of the inner ear was established to investigate the effects of canalithiasis of BPPV on the balance function of the inner ear.The movement of otolith particles in the membranous labyrinth was simulated when a person turns his head to a specific position.The effects of otolith movements on the balance function of the inner ear were simulated for different numbers,diameters,and initial positions of otoliths.The simulation results show that the otolith diameter affects the movement duration of otoliths in the membranous labyrinth.The number and diameter of otoliths,the diameter of the membranous labyrinth,and the initial position of the otoliths can cause changes in the pressure difference on both sides of the cupula of the crista ampullaris(cupula).The latent period and onset period are related to the diameter of otolith particles and the position of the head.There is also a correlation between the severity of the disease and the diameter and number of otolith particles.
基金Supported by the earmarked fund for Modem Agro-Industry Technology Research System(CARS-50-G01)the Fund for Outstanding Talents and Innovative Team of Agricultural Scientific Research,the Qingdao Natural Science Foundation(No.12-1-4-12-(1)-jch)the Research Fund for the Postgraduate of Shanghai Ocean University(No.A1-0209-14-0900-5)
文摘This study was conducted to clarify the distribution and morphology of free neuromasts during the development of half-smooth tongue sole （Cynoglossus semilaevis） using scanning electron microscopy. During development, （1） the apical surface of free neuromasts changed in shape from a circle to a four-poiut star; （2） the external structure changed from being level with the epidermis to papilla-like above the level of the epidermis; （3） the neuromast cupula changed from cylindrical to blade-shaped; （4） the free neuromasts went from occurring singly to being in clusters of a few single organs; （5） the arrangement changed from a linear array to no discernable pattern; （6） there was a significant increase in the number of free neuromasts after metamorphosis. In adult C. semilaevis, free neuromasts were only observed on the abocular side of the head. Thus, there were more free neuromasts located on the abocular side of the head with a higher concentration around the anterior nostril and mouth, which may have a mechanical sensory function to help locate food as an adaptation to a benthic mode of life.
