垂直半规管功能检测进展

日常生活中人体依靠前庭、视觉及本体觉组成"平衡三联"维持平衡,而其中前庭系统是司平衡的器官.目前临床上对前庭功能的检测(vestibular function test),常通过视眼动系统、前庭眼反射(vestibulo-ocular reflex,VOR)通路、前庭脊髓通路等几种途径来实现.前庭感受器主要由成对的水平半规管、前垂直半规管、后垂直半规管和两对前庭囊(椭圆囊和球囊)组成,其中冷热试验(caloric test)和旋转试验(rotation test)作为水平半规管功能检测的常用方法已经得到广泛运用,但尚无常规有效检测垂直半规管(vertical semicircular canal)功能的方法[1],所以还不能反映整体的前庭功能,临床常见眩晕性疾病与人体的垂直半规管功能密切相关.     

良性阵发性位置性眩晕半规管功能分析

目的 评估良性阵发性位置性眩晕(benign paroxysmal positional vertigo,BPPV)患者半规管损伤与异位耳石的关系及其损伤频率特征.方法 BPPV患者214例,包括后半规管管石症(posterior semicircular canal canalithasis,PSC-Can) 107例,水平半规管管石症(horizontal semicircular canal canalithasis,HSC-Can) 80例,水平半规管嵴顶结石症(horizontal semicircular canal cupulolithiasis,HSC-Cup) 27例;其中合并有其他疾病者190例(88.8％),无合并疾病者24例(11.2％).三组患者均完成高频视频头脉冲试验(video head impulse test,vHIT)、中频摇头试验(head shaking test,HST)和低频冷热试验三项检查,以vHIT的增益值(vHIT gain,vHIT-G)、HST诱发摇头眼震(head shaking nystagmus,HSN)和冷热试验单侧半规管反应非对称值(unilateral weakness,UW)为指标,分析三组不同责任半规管BPPV患者的三项试验结果特点及其相互关系.结果 所有BPPV患者vHIT、HST及冷热试验的阳性率分别为7.0％、24.3％和71.0％,相差比较明显,经x2检验,差异具有统计学意义(P值均＜0.05);有和无合并疾病的两类BPPV患者上述三项试验的阳性率结果比较,差异无统计学意义(P值均＞0.05).三组BPPV患者每一项试验(vHIT、HST及冷热试验)结果进行组间比较,差异均无统计学意义(P值均＞0.05).三组BPPV患者各组内上述三项试验结果之间比较,差异均具有统计学意义(P值均为0.000).三组冷热试验单侧异常者UW值比较,差异无统计学意义(F=0.970,P=0.383).结论 BPPV多存在与椭圆囊病变同源的半规管损伤,该损伤主要发生在低频区,异位耳石不是其损伤的主要原因;中频HST和高频vHIT不宜用作BPPV半规管损伤的筛查项目.     

水平半规管良性阵发性位置性眩晕患者眼震参数客观特征

目的 探讨水平半规管良性阵发性位置性眩晕(BPPV)眼震的方向、强度、时间等参数的客观特征及机制.方法 水平半规管BPPV患者233例,其中水平半规管管石症(horizontal semicircular canalithasis,HSC-Can) 179例,水平半规管壶腹嵴顶结石症(horizontal semicircular canal cupulolithiasis,HSC-Cup)54例.应用视频眼震图仪分别记录滚转试验诱发眼震,比较各个试验头位的眼震方向、强度、时间等参数特点.采用SPSS17.0统计软件进行数据处理.结果 水平半规管BPPV患者滚转试验在左侧、右侧转头位均可诱发出水平性眼震.HSC-Can诱发眼震方向与转头方向相同,向患侧和健侧转头位诱发眼震的潜伏期(-x±s,下同)为(1.922±1.501)s和(1.447±0.855)s,持续时间为(25.620±10.409)s和(22.110±10.931)s,强度为(56.441±33.168)°/s和(24.239±13.892)°/s,向患侧转头诱发眼震的潜伏期、持续时间及强度均大于健侧,差异均具有统计学意义(t值分别为3.715、15.219和4.070,P值均＜0.01),其中眼震强度之比约为2∶1.HSC-Cup诱发眼震方向与转头方向相反,向健侧转头诱发眼震的强度明显大于向患侧转头,其强度之比约为2∶1,差异具有统计学意义(t=-7.634,P＜0.01);而向健侧和向患侧转头诱发眼震的潜伏期,差异则无统计学意义(t=1.670,P=0.101).HSC-Can滚转试验中向患侧转头诱发眼震的潜伏期、强度均大于HSC-Cup向健侧转头,但差异无统计学意义(t值分别为1.554和0.305,P值均＞0.05).结论 水平半规管BPPV患者滚转试验向左右侧转头诱发眼震的强度均遵循Ewald定律,强弱之比约为2∶1;潜伏期、持续时间及强度等眼震图参数可作为BPPV的客观诊断指标.     

上半规管裂综合征

Minor等于1998年报道了一组以强声刺激、中耳压力或颅内压改变为诱发的眩晕、耳内震动感及平衡紊乱为临床表现的病例,其诱发的眼震方向与上半规管平面一致,颞骨薄层CT显示上半规管顶部骨质部分缺损,其中2例经颅中窝进路手术探查证实上半规管顶裂,故将其命名为“上半规管裂综合征（superior semicircular canal dehiscence syndrome,SSCD）”。此后不断有个案病例报道,该病主要的临床表现为传导性聋和声音或压力诱发的眩晕。本病在临床上容易漏诊,现将有关的文献资料结合临床表现介绍如下。     

三半规管阻塞与迷路切除术后前庭功能动态变化

目的：比较豚鼠三半规管阻塞与迷路切除术后前庭功能代偿的异同。材料与方法：将15只健康豚鼠分为2组，其中8只豚鼠行右侧三半规管阻塞术（triple semicircular canal occlusion,TCO)，7只豚鼠行右侧迷路切除术（labyruinthectomy,LE)，于术后一个月内观察豚鼠行为学及眼震电图（ENG）的动态变化，结果：发现术后第1天两组均出现自发性眼震，正弦摆动刺激术侧时未引出衣发性眼震，头向右侧偏斜并沿地面垂直轴向术侧旋转；LE组却出现番滚现象，术后第3，5，10，15，30天正弦摆动眼震试验，两组豚鼠术侧眼震均随时间的推移逐渐恢复，TCO组于15天左右向眼震基本恢复对称，而LE组至术后30天仅摆动幅度120，150度，180度左右向眼震基本对称，摆动幅度为60度，90度双向眼震反应差异仍有显著意义（P＜0．05），。另外，LE组有3只豚鼠仍存在头偏，结论：TCO组要比LE组动物恢复快，建立代偿和失平衡时间短。     

后半规管良性阵发性位置性眩晕患者复位中眼震分析

目的 分析后半规管良性阵发性位置性眩晕(posterior semicircular canal benign paroxysmal positional vertigo,PC-BPPV)患者复位中的眼震,探讨BPPV可能的发病机制.方法 2007年12月至2008年4月眩晕门诊就诊的66例PC-BPPV患者,详细记录病史、体位试验及复位中不同位置眼震的情况,对PC-BPPV患者可能发病机制进行探讨.结果 变位试验完伞符合贵阳会议诊断标准的66例PC-BPPV患者,采用改良Epley复位,视频眼震记录技术记录复位中四个位置的眼震方向及强度,24例患者复位中出现的眼震均为垂直扭转向上眼震;21例除第一个位置出现上向扭转眼震,其余三个位置眼震阴性;7例变位试验初诊PC-BPPV的患者在第二次复位中出现强烈水平眼震;14例患者复位的第二或第三个位置出现下向垂直眼震.由复位中不同位置出现的眼震分析,66例确诊为PC-BPPV的患者,52例复位中的表现符合管石及嵴顶耳石症理论,占78.8%.结论 除了目前公认的管石症及嵴顶耳石症理论外,推测部分PC-BPPV可能与耳石器官及球囊椭圆囊神经病变有关.     

双温试验中不同刺激顺序下眼震强度比较

目的比较双温试验中不同的冷、热刺激顺序下冷、热气刺激引起的眼震强度的不同。方法对40例正常对照者和自2004～2006年来我院就诊的229例有眩晕主诉的患者,随机分为两组,先冷后热刺激组包括20例正常对照者和101例患者,刺激顺序是①右冷,②左冷,③右热,④左热。先热后冷刺激组包括20例正常对照者和128例患者,刺激顺序是①右热,②左热,③右冷,④左冷。取眼震最强的10秒钟计算眼震最大慢相速度;眩晕患者按照半规管轻瘫指数(canal paresis,CP)≥20%为标准,分为半规管功能正常组和半规管轻瘫组,比较各组不同刺激顺序下冷、热气刺激引起的眼震强度。结果正常对照者先热后冷刺激组,右耳的冷、热气刺激引起的眼震强度无差异,其余各组比较耳冷、热气刺激引起的眼震强度差别有明显统计学意义,而且优先刺激者眼震强。对第1次刺激耳的眼震强度进行比较,正常对照者和半规管轻瘫的眩晕患者眼震强度无差异,而半规管功能正常的眩晕患者热气刺激引起的眼震强。结论双温试验中冷、热气刺激引起的眼震强度相似;不同的刺激顺序对于冷、热气刺激引起的强度有影响,优先刺激者引起的眼震强;正常人中,冷气优先刺激引起的眼震强度明显强,前庭适应更加明显。     

三半规管阻塞与迷路切除术后前庭功能动态变化

目的 :比较豚鼠三半规管阻塞与迷路切除术后前庭功能代偿的异同。材料与方法 :将 15只健康豚鼠分为 2组 ,其中 8只豚鼠行右侧三半规管阻塞术 (triple semicircular canal occlusion,TCO) ,7只豚鼠行右侧迷路切除术(labyrinthectomy,L E) ,于术后一个月内观察豚鼠行为学及眼震电图 (ENG)的动态变化。结果 :发现术后第 1天两组均出现自发性眼震 ,正弦摆动刺激术侧时未引出诱发性眼震 ,头向右侧偏斜并沿地面垂直轴向术侧旋转 ;L E组却出现翻滚现象。术后第 3、5、10、15、30天正弦摆动眼震试验 ,两组豚鼠术侧眼震均随时间的推移逐渐恢复 ,TCO组于 15天左右向眼震基本恢复对称 ,而 L E组至术后 30天仅摆动幅度 12 0°、15 0°、180°左右向眼震基本对称 ,摆动幅度为 6 0°、90°双向眼震反应差异仍有显著性意义 (P <0 .0 5 ) ;另外 ,L E组有 3只豚鼠仍存在头偏。结论 :TCO组要比 L E组动物恢复快 ,建立代偿和失平衡时间短     

SRM-Ⅳ前庭诊疗系统速度阶跃试验及临床意义

目的研究健康成人应用SRM-Ⅳ前庭诊疗系统进行速度阶跃试验及其特征性参数的正常值,并分析其临床意义。方法 400例健康成人作为受试者,应用SRM-Ⅳ前庭诊疗系统进行速度阶跃试验,记录分析其顺时针和逆时针旋转急停后30s内眼震慢相速度及其慢相速度不对称比和眼震衰减时间的不对称比。结果顺时针和逆时针阶跃旋转急停后30s内眼震平均慢相速度无明显差别,合计其总的眼震平均慢相速度为(19.25±5.47)°/s,95%参考值范围为8.53°/s-29.97°/s;双侧水平半规管旋转急停眼震慢相速度不对称比为(9.15±5.29)%,上限值为17.83%,眼震衰减时间不对称比为(10.92±5.20)%,上限值为19.45%。结论通过SRM-Ⅳ前庭诊疗系统进行速度阶跃试验并建立了旋转急停后30s内眼震慢相速度、两侧眼震慢相速度不对称比和眼震衰减不对称比的正常值。可通过与其他的前庭功能试验的互补而更加全面地评价前庭功能,为眩晕疾病的诊断与康复效果的评价提供客观依据。     

正常人双温试验反应强度和年龄的相关性分析

目的 比较耳科正常人标准双温试验中眼震最大慢相速度的平均值和年龄的相关性.方法 选择20～72岁的耳科正常人,以10岁为一个年龄组,将受试者分为20～、30～、40～、50～、60～72岁五个年龄组,进行标准的双温试验.取四次刺激的眼震最大慢相速度(°/s)的平均值进行比较.结果 5组正常人温度试验中眼震最大慢相速度的平均值分别为:20～岁组:8.39±2.50°/s;30～岁组:11.29±4.71°/s;40～岁组:12.18±5.81°/s;50～岁组:9.56±4.31°/s;60～岁组:11.20±4.53°/s.对各组眼震慢相速度的平均值采用单因素方差分析,相邻各年龄组之间眼震的强度差异没有统计学意义(P＞0.05).结论 随着年龄的增长,双温试验引起的眼震最大慢相速度没有明显的下降,说明水平半规管的功能随着年龄的增长并没有明显下降.     

Neurotological evaluation of vertical semicircular canal function in inner ear malformation. A case report.

A 9-year-old boy with inner ear malformation complained of slight deafness and unsteadiness. CT revealed a normal cochlea despite enlargement of the lateral semicircular canals. The vertical semicircular canals developed more or less normally. The caloric test showed complete canal paresis bilaterally; however, a horizontal rotational stimulus elicited a vestibulo-ocular response, which showed only rightward and downward nystagmus, and their maximal slow-phase velocities were low. In addition, the examination of the vertical semicircular canal function using the head-tilted rotation test revealed a more active response, and the maximal slow-phase velocities were higher than those of a standard horizontal rotational test. These results suggest that the function of the vertical semicircular canal was well preserved and that it may have perceived the horizontal acceleration instead of the lateral semicircular canal.     

Selective stimulation of the equilibrium organ using monochromatic near infrared

BACKGROUND: The aim of this study was, to establish, if a selective thermal warm-stimulation using monochromatic near infrared radiation (NIR) in healthy persons, patients with chronic otitis media (chronic mucosal inflammation) and after radical surgery of one ear shows quantitative or qualitative changes of the nystagmus reaction. PATIENTS AND METHODS: Healthy persons (n = 3), patients with a large central defect of the tympanic membrane (n = 5) and after radical ear surgery (n = 6) were examined. In healthy persons a stimulation with monochromatic NIR (lambda = 980 nm) of several areals of the external auditory canal was performed. In patients with large defects of the tympanic membrane the promontorium was stimulated. In patients with a radical cave of the ear a selective NIR-stimulation of the region of the vertical and the anterior semicircular canal was performed. The horizontal semicircular canal was visible as a landmark. Registration of the nystagmus was performed by means of videonystagmography. RESULTS: In healthy persons the mean slow phase velocity of the nystagmus depended on the stimulated region. But there was no qualitative change of three dimensional eye movement. Stimulation of the promontorium showed a strong directional horizontal nystagmus. In patients with a radical cave the stimulation of the regions of the three semicircular canals showed a qualitative difference in three dimensional eye movement. NIR-stimulation showed in all cases a nystagmus into the stimulated ear. CONCLUSIONS: The method of monochromatic near infrared stimulation can be used for selective stimulation of several regions of the external auditory canal, the promontorium and the regions of the semicircular canals in a radical cave of the ear as well as to prove the warm reaction of the equilibrium organ. A specific nystagmus after stimulation of the semicircular canal-region in a radical cave of the ear could be an indication for a normal semicircular canal function.     

Three-dimensional analysis of caloric nystagmus in the rhesus monkey.

The aim of this study was to investigate whether caloric nystagmus contains response components that can be attributed to a stimulation of the vertical semicircular canals. Three dimensional eye movement recordings with a dual search coil technique revealed important horizontal, vertical and torsional nystagmus components following irrigation of the external ear canal with cold water in various head positions relative to gravity. Horizontal nystagmus components, i.e. lateral semicircular canal vectors, followed a cosine function of both the pitch and yaw angle of the head relative to gravity, confirming a mainly thermovective mechanism for stimulation of the horizontal canals. Vertical and torsional nystagmus components behaved differently following left and right ear irrigations. Right-left symmetrical vectors emerged only when the vertical and torsional components were transposed into vectors of single semicircular canal directions. The intensity of these vertical semicircular canal vectors as a function of the position of the corresponding canal relative to gravity, however, excludes important thermovective mechanisms acting at the vertical canals. It remains an open question whether these vertical canal vectors represent a non-thermovective caloric stimulation of vertical canal afferents.     

On the vertical caloric nystagmus

Eye movements in response to caloric stimuli are recorded traditionally in the horizontal plane only. Twin channel electronystagmographic traces of 124 patients undergoing evaluation of vertigo were reviewed. Thirty traces (24%) were found to include a "true" vertical component to the evoked nystagmus. There was no correlation between the existence and the nature of any vestibular pathology and the presence of the vertical nystagmus. Thus, a vertical component to the caloric nystagmus (the so-called "perverted" caloric nystagmus) is not necessarily a pathological sign, and can be a normal variant, caused by excitation of the vertical semicircular canal - most probably the posterior one. The mechanisms of heat transfer in the temporal bone and the source of this vertical caloric nystagmus are discussed in the context of the published literature.     

Vertical nystagmus provoked by locally applied calorization at the vertical semicircular canals: a study in pigeons

Calorization of the vertical semicircular canals in pigeons was performed by irrigation of water through a polyethylene cannula, that was attached at a selected site to the bony wall of the anterior or posterior canal of the labyrinth. The temperature differences between the stimulated site and the corresponding location inside the contralateral mastoid were detected by two thermistors. (a) Calorization of an anterior or posterior canal evoked a dissociated vertical nystagmus in both eyes. (b) The direction of the nystagmus and of the vertical slow phase velocity proved to be temperature-dependent. (c) The vertical eye movements disappeared when the stimulated canal was placed horizontally during calorization. (d) During parabolic flight the vertical and horizontal eye movements, elicited by sustained calorization, disappeared during short periods of microgravity and proved to be dependent to the g load. (e) All vertical canal calorizations evoked eye movements in the plane parallel to the stimulated canal. Left and right eye moved in opposite vertical directions, depending on the selected site of calorization on the vertical canal. (f) The same mode (warm or cold) of calorization of an anterior canal provoked similar vertical movements of both eyes as compared to the vertical eye movements that were induced by calorization of the contralateral posterior canal. The results are discussed in view of the 'convection current' and the 'expansion/contraction' theory and they are compared to previously reported results of vestibular nerve stimulation.     

Angles between left and right vertical semicircular canals

To clarify anatomical relationships between the left and right vertical semicircular canal (SCC), we measured angles between the left and right posterior SCCs, and angles between left and right anterior SCCs. Subjects were T2 images of axial magnetic resonance imaging (MRI) in 50 patients reporting headaches. The mean angle between the left and right posterior SCC was 92.6 degrees (S.D. = 11.7) and that between the left and right anterior SCC was 76.1 degrees (S.D. = 10.4). These results suggest that angles between the left and right vertical semicircular canals are not always 90 degrees, and interindividual differences in the relationship between canal planes are great, indicating a need for discretion in analyzing peripheral nystagmus.     

Hunt综合征伴眩晕患者的半规管损伤频率特征

目的 探讨Hunt综合征伴眩晕患者的前庭半规管损伤频率特征以及视频头脉冲试验(video head impulse test,vHIT)在评估其前庭功能中的应用价值.方法 Hunt综合征伴眩晕患者26例(病例组)分别进行高频vHIT、中频摇头试验(head shaking test)和低频冷热试验(caloric test);30例健康人为对照组进行vHIT.以冷热试验单侧半规管反应非对称值(unilateral weakness,UW)、摇头试验诱发摇头眼震(head shaking nystagmus,HSN)、vHIT的增益值(video head impulse test gain,vHIT-G)为观察指标,应用SPSS 16.0统计软件分析对照组vHIT-G、病例组的三项试验结果特点及其相关性.结果 对照组6个半规管的vHIT-G均符合正态分布,方差分析,相互间差异无统计学意义(F=0.005,P＜0.01);双侧前、水平和后半规管平均vHIT-G((x)±s,下同)分别为16.80％±9.80％、16.57％±10.30％、16.52％±11.12％;病例组的患耳前、水平和后半规管vHIT-G分别为46.96％±34.54％、75.35％±35.29％、41.65％±32.87％,均符合正态分布,与对照组对应半规管比较差异有统计学意义(P值均＜0.01);vHIT、摇头试验和冷热试验阳性者分别为23例(88.46％)、22例(84.61％)和24例(92.31％),双侧确切概率法x2检验,P值均＞0.05,差异无统计学意义;UW与水平半规管vHIT-G之间存在正相关(r=0.692,P＜0.01).结论 Hunt综合征伴眩晕患者的半规管功能损伤呈多频或近乎全频性损伤,具有传导阻滞性神经损伤特点;vHIT可以作为Hunt综合征伴眩晕患者前庭功能评定的有效检查方法.     

Caloric vertical nystagmus: the vertical semicircular canal in caloric testing

Vertical nystagmus elicited by caloric testing does not necessarily mean there is central pathology. In a patient with confirmed peripheral vestibular disease, caloric stimulation produced an intense vertical nystagmus, which showed all the features of a caloric nystagmus. The patient had bilateral mastoid cavities, allowing easy stimulation of the posterior semicircular canal, using air. At the same time, a unilateral horizontal semicircular canal functional loss was observed, raising the possibility of dissociated canal dysfunction.     

Vertical vestibulo-ocular reflex in patients with benign paroxysmal positional nystagmus

The vertical vestibulo-ocular reflex (VOR) was tested in 13 patients with benign paroxysmal positional nystagmus and in ten normal subjects. Patients and normal subjects were rotated in the sagittal plane and in the plane of the vertical semicircular canal pairs using sine and step stimuli. Gain, phase, and time-constant measurements of the vertical components of induced nystagmus were not significantly different (P greater than normal 0.05) in the normal subjects and patients for any test condition. At least for the range of test stimuli used in this study, the dynamics of the vertical VOR were normal in patients with benign paroxysmal positional nystagmus.     

Is it possible to diagnose Posterior Semicircular Canal BPPV from the sitting position? The role of the Head Pitch Test and the upright tests along the RALP and LARP planes

PurposeThe diagnosis of benign paroxysmal positional vertigo (BPPV) involving the posterior semicircular canal (PSC) is traditionally entrusted to positioning tests where patients are rapidly brought in the supine position. This prospective study aims to define the role of a diagnostic protocol for PSC-BPPV including only upright tests.Materials and methods109 patients with PSC-BPPV were enrolled. The Head Pitch Test (HPT) was carried out first. If uneventful, the patient's head was turned 45° to each side and bent back-and-forth along the plane aligning either with the right anterior-left posterior (RALP) or left anterior-right posterior (LARP) canals, thus performing the upright RALP / upright LARP (uRALP/uLARP) test. Nystagmus observed was used to predict the diagnosis, which was therefore confirmed by Dix-Hallpike tests.ResultsPSC-BPPV could be correctly diagnosed in 75.2% of cases with the sole HPT and in 87.2% of cases by adding the uRALP/uLARP test (Upright Protocol). The time elapsed from symptoms onset was closely related to the protocol sensitivity, as it reached 100% (64/64) in acute patients while decreased to 68.9% (31/45) in cases evaluated after 7 days (p < 0.001).ConclusionsUpright maneuvers could correctly diagnose PSC-BPPV in most cases. uRALP/uLARP test demonstrated to improve the sensitivity of the HPT, mainly in recent-onset BPPV.