Prospective study of positional nystagmus in 100 consecutive patients

OBJECTIVES: The purpose of this study was to investigate the various diagnoses of patients who present with positional nystagmus. METHODS: Positional maneuvers were systematically performed in the plane of the posterior canal (PC; Dix-Hallpike maneuver) and the horizontal canal (HC; patients were rolled to either side in a supine position) on 490 consecutive patients essentially referred for vertigo and/or gait unsteadiness. RESULTS: One hundred patients (20%) presented positional nystagmus. This nystagmus had a peripheral origin in 83 patients, including 80 patients with benign paroxysmal positional vertigo (BPPV). In BPPV, the PC was involved in 61 patients, the HC in 18 patients (geotropic horizontal nystagmus in 11 and ageotropic in 7; changing from geotropic to ageotropic or the reverse in 4 patients), and both the PC and HC in 1 patient. There was evidence of central positional nystagmus in 12 patients, including positional downbeat nystagmus during the Dix-Hallpike maneuver in 7 patients with various neurologic disorders, and ageotropic horizontal nystagmus during the HC maneuver in 2 patients with, respectively, cerebellar ischemia and definite migrainous vertigo. The peripheral or central origin of the positional nystagmus could not be ascertained in 5 patients, including 1 patient with probable migrainous vertigo and another with possible anterior canal BPPV. CONCLUSIONS: A rotatory-upbeat nystagmus in the context of PC BPPV, a horizontal nystagmus, whether geotropic or ageotropic, due to HC BPPV, and a positional downbeat nystagmus related to various central disorders are the 3 most common types of positional nystagmus. Geotropic horizontal positional nystagmus and, most certainly, horizontal positional nystagmus changing from geotropic to ageotropic or the reverse point to HC BPPV. In contrast, an ageotropic horizontal positional nystagmus that is not changing (from ageotropic to geotropic) may indicate a central lesion.     

Combined horizontal and posterior canal benign paroxysmal positional vertigo in three patients with head trauma

We report 3 patients who complained of positional vertigo shortly after head trauma. Positional maneuvers performed in the plane of the posterior canal (PC; Dix-Hallpike maneuver) and the horizontal canal (HC; patients were rolled to either side in a supine position with the head raised 30 degrees) revealed a complex positional nystagmus that could only be interpreted as the result of combined PC and HC benign paroxysmal positional vertigo (BPPV). Two patients had a right PC BPPV and an ageotropic HC BPPV, and 1 patient had a bilateral PC BPPV and a left geotropic HC BPPV. All 3 patients were rapidly free of vertigo after the PC BPPV was cured by the Epley maneuver and the geotropic HC BPPV was cured by the Vannucchi method. The ageotropic HC BPPV resolved spontaneously. Neuroimaging (brain computed tomography and/or magnetic resonance imaging scans) findings were normal in all 3 patients. From a physiopathological viewpoint, it is easy to conceive that head trauma could throw otoconial debris into different canals of each labyrinth and be responsible for these combined forms of BPPV. Consequently, in trauma patients with vertigo, it is mandatory to perform the Dix-Hallpike maneuver, as well as supine lateral head turns, in order to diagnose PC BPPV, HC BPPV, or the association of both. Early diagnosis and treatment of BPPV may help to reduce the postconcussion syndrome.     

Pathological localization of so-called posterior canal BPPV

OBJECTIVE: Based on the hypothesis that the origin of nystagmus is from the posterior canal (PC), the nystagmus in the head hanging and sitting position should be mirror images. To clarify the anatomical origin of positioning nystagmus in BPPV patients, we analyzed the positioning nystagmus of benign paroxysmal positioning vertigo (BPPV) patients three-dimensionally. METHODS: Twenty-six patients with BPPV participated in this study. The positioning nystagmus was recorded in complete darkness from the patient's left eye by means of an infrared CCD camera. We performed three-dimensional analysis of nystagmus using video image analysis system (VIAS). Subsequently, the rotation axis of the 3D eye movements of the positioning nystagmus was calculated. RESULTS: Among the 26 patients tested, 20 patients demonstrated the axes of nystagmus in good or relatively good alignment to the PC axis. However, in 11 of these 20 patients there was poor alignment of the axis of nystagmus in the sitting position to the PC axis. In addition, six patients showed axes of nystagmus with poor alignment to the PC in the head hanging position. Among them, two patients exhibited axes of nystagmus in good alignment with the anterior canal, in spite of diagnosis of these patients as PC BPPV by experienced examiner based on the positioning nystagmus test. CONCLUSION: These results demonstrated that only one-third of patients who were diagnosed as BPPV, could be diagnosed as true BPPV which originates from a PC pathology. Besides the possibility that the pathology may originate from the AC, it is still unclear which part of the inner ear may be the candidate site of origin of the pathology of BPPV in the other 15 patients.     

Treatment of benign positional vertigo using the semont maneuver: efficacy in patients presenting without nystagmus

OBJECTIVE: To evaluate and compare the efficacy of the Semont liberatory maneuver on "objective" benign paroxysmal positional vertigo (BPPV) defined as vertigo with geotropic nystagmus in Dix-Hallpike positioning versus "subjective" BPPV defined as vertigo without nystagmus in Dix-Hallpike positioning. STUDY DESIGN: Retrospective chart review. METHODS: One hundred sixty-two patients with positional vertigo during Dix- Hallpike positioning were identified. Patients were evaluated for the presence or absence of nystagmus. All patients underwent the Semont liberatory maneuver. The patient's condition at follow-up was documented at 3 weeks as complete, partial, or failure. Repeated procedures were performed if necessary. RESULTS: There were 127 cases of objective BPPV and 35 cases of subjective BPPV. Overall, 90% of all patients tested had significant improvement of their vertigo after 1.49 maneuvers on average. Improvement was seen in 91% of patients with objective BPPV after 1.59 maneuvers on average, compared with 86% in subjective BPPV after 1.13 maneuvers on average (chi2 test, not significant [P = .5]). Patients with a history of traumatic origin or cause had an overall success rate of 81% compared with 92% for nontraumatic causes or origins (chi2 test, not significant [P = .1]). Recurrences were seen in 29% of patients after a successful initial maneuver; however, 96% of these patients responded to further maneuvers. Four patients with persistent symptoms after conservative management underwent posterior semicircular canal occlusion with resolution of symptoms. CONCLUSION: The Semont liberatory maneuver provides relief of vertigo in patients with positional vertigo, even in patients without objective nystagmus.     

上半规管良性阵发性位置性眩晕41例

目的 探讨上半规管良性阵发性位置性眩晕(BPPV)诊断和治疗的最佳方案。方法 回顾性分析41例上半规管BPPV患者的病历资料,并对所有患者的诊断及复位进行评估分析。结果 SRM-Ⅳ模拟Dix-Hallpike试验诱发出典型垂直向下眼震28例(68.3%),其中眼震伴有向地扭转的成分19例,不伴有扭转成分9例;SRM-Ⅳ上半规管BPPV诱发试验诱发出典型垂直向下眼震35例(84.6%),其中眼震伴有向地扭转的成分30例,不伴有扭转成分5例。在所有41例患者中有38例能通过两种诱发试验对受累侧别做出判断,其中因诱发眼震伴有扭转成分而判断侧别30例,单侧诱发诱发出垂直向下眼震且不伴有扭转成分3例,双侧诱发出垂直向下眼震5例,且不伴有扭转成分,但因眩晕及眼震的强度有明显差别而判断出侧别,患者对受累侧别不能判断3例。在能判断出侧别的38例患者中有左侧上半规管受累25例,右侧上半规管受累13例。对41例采用SRM-Ⅳ上半规管BPPV复位法进行治疗,通过一次治疗痊愈28例,有效12例,无效1例。结论 上半规管BPPV 临床上被越来越重视,应用SRM-ⅣBPPV诊疗系统对上半规管BPPV进行诊治效果好,应该在临床得到推广。     

Comparison between objective and subjective benign paroxysmal positional vertigo: clinical features and outcomes

Conclusions: Objective benign paroxysmal positional vertigo (O-BPPV) and subjective BPPV (S-BPPV) have similar demographic and clinical features. Canalith repositioning manoeuvres (CRMs) can be an effective treatment for patients with S-BPPV, and a diagnosis of positional nystagmus is not essential for considering CRMs. This study supports the use of CRMs as the primary treatment for S-BPPV.

Objective: To examine differences in demographic and clinical features, as well as treatment outcomes, between O-BPPV and S-BPPV.

Methods: The medical records of 134 patients with BPPV were reviewed for demographic characteristics, past medical history, associated symptoms, response to CRMs, interval between symptom onset and the first medical visit, and recurrence rate. The O-BPPV group (n?=?101) comprised patients who experienced vertigo and accompanying autonomic symptoms, and showed typical nystagmus. The S-BPPV group (n?=?33) comprised patients who, when subjected to a provoking manoeuvre, showed all of the classic BPPV symptoms but did not show nystagmus. All patients had at least 3 years of follow-up.

Results: The demographics (age and sex ratio), past medical history, and associated symptoms were not significantly different between the two groups. Posterior semi-circular canal BPPV appeared more than twice as often as horizontal semi-circular canal BPPV in patients with S-BPPV. However, both canals were affected to a similar proportion in patients with O-BPPV, and the difference was marginally significant (p?=?0.073). Overall improvement was better in O-BPPV than in S-BPPV; however, there was no significant difference. The total numbers of manoeuvres for recovery and the interval between symptom onset and the first medical visit also did not show any significant inter-group differences. During a 3-year follow-up, the recurrence rate was 13.8% for O-BPPV and 21.2% for S-BPPV.     

Clinical features of benign paroxysmal positional vertigo

Our understanding of the pathomechanism of benign paroxysmal positional vertigo (BPPV) has improved dramatically. A type of BPPV featuring mixed torsional and vertical nystagmus induced by the Dix-Hallpike maneuver involves the posterior semicircular canal (P-BPPV). The other type of BPPV featuring horizontal nystagmus induced by spine-to-lateral head positioning involves the horizontal canal BPPV (H-BPPV). In complaints of vertigo or dizziness, 619 patients visited our department last year. Of these, 142 (23%) was had positional nystagmus consistent with a diagnosis of BPPV, 118 (19%) had no nystagmus but were suspected of BPPV due to vertigo episodes. BPPV was the most frequent diagnosis. H-BPPV was not rare, but accounted for 30% of BPPV. Of H-BPPV, 73% featured direction changing geotropic nystagmus, and 27% direction changing apogeotropic nystagmus. H-BPPV resolved faster than P-BPPV. Most cases caused by head trauma were P-BPPV. Transition between P- and H-BPPV was found in 6 cases. Women outnumbered men by about 3 to 2 in both P- and H-BPPV. Peak incidence was found in the those in their 60s and 70s, suggesting that the etiologies of both types of BPPV are essentially the same.     

Multiple positional nystagmus suggests multiple canal involvement in benign paroxysmal vertigo

CONCLUSION: Video-oculography demonstrates a higher occurrence of atypical positional nystagmus in patients with benign paroxysmal positional vertigo (BPPV). This includes anterior and horizontal canal variants and multiple positional nystagmus, suggesting combined lesions affecting several canals. OBJECTIVE: To analyse the video-oculographic findings of positional tests in patients with BPPV. MATERIAL AND METHODS: Seventy individuals with symptoms of BPPV and positional nystagmus were included in this study. The diagnosis was based on a history of brief episodes of vertigo and the presence of positional nystagmus as confirmed by video-oculographic examination during the Dix-Hallpike test, the McClure test or the head-hanging manoeuvre. Patients were treated by means of different particle repositioning manoeuvres according to the affected canal (Epley's manoeuvre for the posterior or anterior canals and Lempert's manoeuvre for the lateral canal) and the effectiveness was evaluated at 7 and 30 days. RESULTS: Twenty-nine individuals (41.43%) presented an affected unilateral posterior canal. Fifteen patients (21.43%) presented a pure horizontal direction-changing positional nystagmus consistent with a diagnosis of horizontal canal BPPV. Twelve individuals (17.14%) presented a unilateral down-beating nystagmus, suggesting possible anterior canal BPPV. In addition, 14 patients (20%) showed multiple positional nystagmus during the examination corresponding to simultaneous multi-canal BPPV, 5 had bilateral posterior canal BPPV and 2 presented a positional down-beating nystagmus in both left and right Dix-Hallpike manoeuvres and the head-hanging manoeuvre, which is highly suggestive of anterior canal BPPV. However, seven individuals showed positional horizontal and vertical side-changing nystagmus that could not be explained by single-canal BPPV. These patients with multiple positional nystagmus showed changing patterns of positional nystagmus at follow-up.     

水平半规管良性阵发性位置性眩晕的诊断

目的探讨水平半规管良性阵发性位置性眩晕（BPPV）的诊断。方法自2003年1月至2006年9月，本眩晕中心共确诊为水平半规管BPPV（HSC BPPV）患者46例。诊断依据为典型的病史及用红外视频眼震电图仪记录患者在Dix—Hallpike试验和滚转试验中的眼震结果，并排除其他疾病。研究HSC BPPV的眼震特点。结果441例诊断为BPPV患者中，46例（10．43％）为水平半规管BPPV。其中38例（82．61％）为单侧病变，5例（10．87％）患者合并同侧后半规管病变，3例（6．52％）为双侧病变。35例患者通过两种试验诱发出水平眼震，11例患者仅通过滚转试验诱发出水平眼震。25例患者眼震方向向地，13例患者眼震方向背地，3例患者眼震方向不固定，5例患者各种手法诱发出同一方向的眼震。29例患者在双侧手法中出现眼震，17例患者在一侧手法中出现眼震。结论HSC BPPV眼震为完全水平性且多为快相向地。通常受累耳在双侧手法中均可出现眼震，以向患侧为重。一侧水平半规管和后半规管可同时受累。滚转试验在HSC BPPV检查中比Dix—Hallpike试验更加敏感。Dix—Hallpike试验结合滚转试验可使更多的HSCBPPV患者得到确诊．     

Persistent positional nystagmus

Involvement of the superior semicircular canal (SSC) in benign paroxysmal positional vertigo (BPPV) is rare. SSC BPPV is distinguished from the more common posterior semicircular canal (PSC) variant by the pattern of nystagmus triggered by the Dix-Hallpike position: down-beating torsional nystagmus in SSC BPPV versus up-beating torsional nystagmus in PSC BPPV. SSC BPPV may be readily treated at the bedside, which is a key component in excluding central causes of down-beating nystagmus. We present an unusual video case report believed to represent refractory SSC BPPV based on the pattern of nystagmus and the absence of any other central signs.     

Horizontal canal type BPPV: bilaterally affected case treated with canal plugging and Lempert's maneuver

A 54-year-old woman complained of positional vertigo. During 3 months' observation, the patient showed mostly geotropic or apogeotropic nystagmus due to right canalolithiasis or cupulolithiasis, however, she sometimes showed nystagmus which suggested left horizontal canalolithiasis. We suspected that she suffered from bilateral horizontal canal type benign paroxysmal positional vertigo (BPPV) and performed Lempert's maneuver for both directions, however, they were ineffective. She underwent canal plugging for right horizontal canal. After surgery she showed no positional nystagmus of right horizontal canal origin. However, apogeotropic nystagmus of the left horizontal canal origin was still observed. This nystagmus changed to geotropic nystagmus and finally disappeared following Lempert's maneuver for the left side. Bilateral horizontal canal BPPV is difficult to be resolved, probably because physical treatment for one side would move debris to the cupula in the other canal. Canal plugging combined with Lempert's maneuver to the other side is one treatment option for intractable bilateral horizontal canal BPPV.     

Oculographic findings in 145 patients with benign paroxysmal positional vertigo

ObjectiveBenign paroxysmal positional vertigo (BPPV) can be produced by specific manoeuvres and be studied by electrooculography (EOG). It allows an exhaustive study of features in the positional nystagmus. Although most of the patients with BPPV express typical nystagmus, there exists a group of them that exhibit a non typical form. In this work, a comparative study was carried out between two groups of patients.Material and methodsWe have studied retrospectively 145 patients with BPPV and Dix-Hallpicke (D-H) positive manoeuvre registered by EOG techniques. All patients were explored in a complete EOG tests. Two groups were identified: typical response/atypical response according to the features of nystagmus response. Possible alterations in other EOG tests in each group were investigated and differences between both types of response were analyzed.Results83.5% of cases showed typical nystagmus and atypical in the rest. Other EOG alterations observed in these patients, were (group typical response/atypical response): caloric hypofunction (17.3%/23%), positional nystagmus (12.4%/62.5%), alterations in visual-oculomotor function tests (10%/50%).ConclusionsFrequent alterations were observed in the classic manoeuvres and also in the rest of EOG tests. Probably atypical response in the first is due to or can explain the existence of the second.     

Multiple positional nystagmus suggests multiple canal involvement in benign paroxysmal positional vertigo

Conclusion. Video-oculography demonstrates a higher occurrence of atypical positional nystagmus in patients with benign paroxysmal positional vertigo (BPPV). This includes anterior and horizontal canal variants and multiple positional nystagmus, suggesting combined lesions affecting several canals. Objective. To analyse the video-oculographic findings of positional tests in patients with BPPV. Material and methods. Seventy individuals with symptoms of BPPV and positional nystagmus were included in this study. The diagnosis was based on a history of brief episodes of vertigo and the presence of positional nystagmus as confirmed by video-oculographic examination during the Dix–Hallpike test, the McClure test or the head-hanging manoeuvre. Patients were treated by means of different particle repositioning manoeuvres according to the affected canal (Epley's manoeuvre for the posterior or anterior canals and Lempert's manoeuvre for the lateral canal) and the effectiveness was evaluated at 7 and 30 days. Results. Twenty-nine individuals (41.43%) presented an affected unilateral posterior canal. Fifteen patients (21.43%) presented a pure horizontal direction-changing positional nystagmus consistent with a diagnosis of horizontal canal BPPV. Twelve individuals (17.14%) presented a unilateral down-beating nystagmus, suggesting possible anterior canal BPPV. In addition, 14 patients (20%) showed multiple positional nystagmus during the examination corresponding to simultaneous multi-canal BPPV, 5 had bilateral posterior canal BPPV and 2 presented a positional down-beating nystagmus in both left and right Dix–Hallpike manoeuvres and the head-hanging manoeuvre, which is highly suggestive of anterior canal BPPV. However, seven individuals showed positional horizontal and vertical side-changing nystagmus that could not be explained by single-canal BPPV. These patients with multiple positional nystagmus showed changing patterns of positional nystagmus at follow-up.     

Benign paroxysmal positional vertigo

Benign paroxysmal positional vertigo (BPPV) is characterized by positional vertigo (brief attacks of rotatory vertigo triggered by head position changes in the direction of gravity) and is the most common peripheral cause of vertigo. There are two types of BPPV pathophysiology: canalolithiasis and cupulolithiasis. In canalolithiasis, otoconial debris is detached from the otolithic membrane and floats freely within the endolymph of the canal. In cupulolithiasis, the otoconial debris released from the otolithic membrane settles on the cupula of the semicircular canal and the specific gravity of the cupula is increased. Consensus has been reached regarding three subtypes of BPPV: posterior-canal-type BPPV (canalolithiasis), lateral-canal-type BPPV (canalolithiasis) and lateral-canal-type BPPV (cupulolithiasis). In the interview-based medical examination of BPPV, questions regarding the characteristics of vertigo, triggered movement of vertigo, duration of vertigo and cochlear symptoms during vertigo attacks are important for the diagnosis of BPPV. The Dix–Hallpike test is a positioning nystagmus test used for diagnosis of posterior-canal-type BPPV. The head roll test is a positional nystagmus test used for diagnosis of lateral-canal-type BPPV. When the Dix–Hallpike test is repeated, positional nystagmus and the feeling of vertigo typically become weaker. This phenomenon is called BPPV fatigue. The effect of BPPV fatigue typically disappears within 30 min, at which point the Dix–Hallpike test again induces clear positional nystagmus even though BPPV fatigue had previously caused the positional nystagmus to disappear. For the treatment of BPPV, sequential head movements of patients can cause the otoconial debris in the semicircular canal to move to the utricle. This series of head movements is called the canalith repositioning procedure (CRP). The appropriate type of CRP depends on the semicircular canal in which the otoconial debris is located. The CRP for posterior-canal-type BPPV is called the Epley maneuver, and the CRP for lateral-canal-type BPPV is called the Gufoni maneuver. Including a time interval between each head position in the Epley maneuver reduces the immediate effect of the maneuver. This finding can inform the development of methods for reducing the effort exerted by doctors and the discomfort experienced by patients with posterior-canal-type BPPV during the Epley maneuver.     

颗粒复位法治疗后半规管良性阵发位置性眩晕

目的 评价颗粒复位法治疗良性阵发性位置性眩晕的效果。方法 对１９９６年７月－１９９８年６月间治疗的３１一半规管性良性性位置性眩晕患者进行回顾分析。地规管耳右症假说,患者接受１次颗粒复位法治疗。治疗结束２周后复查并评价疗效。结果 ２１例患者的眩晕和眼一立刻或在１－２周内逐渐消失。６例改善,４例无效。总有效率８７．１％。结论 颗粒复位法对大多数良性阵发性位置性眩晕患者有效,推荐作为治疗该的首选方法。     

The test and treatment methods of benign paroxysmal positional vertigo and an addition to the management of vertigo due to the superior vestibular canal (BPPV‐SC)

A review of the tests and treatment manoeuvres for benign paroxysmal positional vertigo of the posterior, horizontal and superior vestibular canals is presented. Additionally, a new way to test and treat positional vertigo of the superior vestibular canal is presented. In a prospective study, 57 out of 305 patients' visits are reported. They had residual symptoms and dizziness after the test and the treatment of benign paroxysmal positional vertigo of the horizontal canal (BPPV‐HC) and posterior canal (PC). They were tested with a new test and treated with a new manoeuvre for superior canal benign paroxysmal positional vertigo (BPPV‐SC). Results for vertigo in 53 patients were good; motion sickness and acrophobia disappeared. Reactive neck tension to BPPV was relieved. Older people were numerous among patients and their quality of life (QOL) improved.     

Dynamics of canal response to head-shaking test in benign paroxysmal positional vertigo

CONCLUSIONS: Time constant and maximum slow phase velocity (SPV) of head-shaking nystagmus (HSN) demonstrated a differential canal response to head shaking in 24% of patients with posterior canal benign paroxysmal positional vertigo (BPPV). We suggest that vestibular lithiasis has a limited contribution to the mechanism that generates HSN. OBJECTIVE: To determine the canal response to head shaking in BPPV. PATIENTS AND METHODS: This was a case-control study including 104 individuals with BPPV. The diagnosis was based on the presence of vertigo and nystagmus during the positional test. Subjects were examined by the horizontal and vertical head-shaking test. Eye movements were recorded on a video camera to analyze the nystagmus. The head was shaken passively in the horizontal and sagittal planes, respectively, for horizontal and vertical HSN at a frequency of 2 Hz. HSN was considered when six consecutive beats of nystagmus with an SPV of at least 2 degrees/s were detected. Main outcome measures were the presence of horizontal and vertical HSN, maximum SPV of HSN, time constant of HSN, and canal paresis. RESULTS: Maximum SPV of vertical HSN was higher in BPPV patients with posterior canal BPPV (n = 10) than in controls (p = 0.04). Moreover, the time constant of vertical HSN was significantly lower for posterior canal BPPV when compared with controls (p < 0.02).     

不同类型良性阵发性位置性眩晕的诊断和治疗

目的探讨不同类型良性阵发性位置性眩晕（benign paroxysmal positional vertigo，BPPV）的诊断和治疗方法。方法对我科2004年4月-2006年3月就诊的BPPV病人131例．应用红外线视频眼动记录分析变位试验诱发的眼震特点，进行分型、定侧，并采用相应的耳石复位技术治疗。结果（1）后半规管BPPV94例（71．8％），随机分组采用Epley管石复位法和Semont管石解脱法各47例。（2）水平半规管BPPV29例（22．1％），水平向地性眼震者16例，另13例为水平背地性眼震者，自行或采用Gufoni疗法后转换为水平向地性9例，方向不能转换4例。采用barbecue翻滚和／或强迫侧卧体位疗法。（3）前半规管BPPV6例（4．6％），采用Epley管石复位法。（4）混合型BPPV2例（1．5％），行上述相应半规管的疗法。1周后随访总有效率85．5％（112／131），3个月后92.4％（121／131）。结论BPPV的诊断和治疗应根据不同变位试验诱发的眼震特征判别不同半规管及不同发病机理类型，并选择合适的耳石复位技术治疗。     

上半规管良性阵发性位置性眩晕的诊断及治疗

目的探讨上半规管良性阵发性位置性眩晕（benign paroxysmal positional vertigo，BPPV）的诊断和治疗。方法回顾性分析了上半规管BPPV患者31例，并对所有患者采用管石复位法治疗后的效果进行评估。结果在Dix-Hallpike检查中，所有患者均诱发出垂直向下的眼震。22例（70．97％）患者一侧诱发出眼震，其中17例眼震伴有扭转成分，5例眼震不伴扭转成分。其余9例（29．03％）患者双侧诱发出现眼震，眼震伴有扭转成分的7例，其中2例眼震扭转方向指向同一侧，4例眼震的扭转方向不固定，1例患者仅一侧出现扭转成分。另外2例患者眼震不伴扭转成分。受累侧别明确诊断的19例（61．29％），其中11例为左侧上半规管受累，8例为右侧上半规管受累。受累侧别未明确诊断的12例（38．71％）。所有患者中，11例（35．48％）患者同时合并后半规管受累。对所有患者采取管石复位法治疗，21例（67．74％）痊愈，29例（93．55％）有效、2例（6．45％）无效。其中首次治愈14例（45．16％），平均治愈次数为1．71次。随访期间5例复发。结论上半规管BPPV临床中少见。在变位检查中，眼震的扭转成分较弱，临床中不易观察。在部分单侧上半规管BPPV患者中，双侧检查均能诱发眼震。管石复位法是治疗上半规管BPPV简单有效的手段。     

Anterior semicircular canal benign paroxysmal positional vertigo and positional downbeating nystagmus

PURPOSE: The aim of this study was to describe the clinical features and video-oculographic findings in patients with anterior semicircular canal benign paroxysmal positional vertigo (BPPV). MATERIALS AND METHODS: STUDY DESIGN: This is a prospective case series. SETTING: The study was set at an outpatient clinic in a general hospital. PATIENTS: Fourteen individuals with symptoms of BPPV and positional downbeating nystagmus (pDBN) were included in the study. The diagnosis was based on a history of brief episodes of vertigo and the presence of pDBN confirmed in the video-oculographic examination during Dix-Hallpike test (DH) or head-hanging maneuver. INTERVENTION: Patients were treated by particle repositioning maneuver and the effectiveness was evaluated at 7, 30, and 180 days posttreatment. The treatment was repeated up to 4 times if pDBN was persistent. MAIN OUTCOME MEASURES: The main outcome measure is the number of patients without pDBN at 30 and 180 days. RESULTS: Video-oculography showed a predominant pDBN in response to DH. Of the 14 patients, 7 had arterial hypertension, and 5 of 14 cases presented abnormalities on the caloric test. Horizontal spontaneous nystagmus was found in 3 of 14 individuals. Positional nystagmus at different positional test was observed in 5 of 14 individuals, suggesting the involvement of several canals. Of the 14 patients, 10 (71%) did not present vertigo, and the positional tests were negative at 30 days. However, 3 cases presented a positive DH with persistence of BPPV episodes and pDBN at 30 days, and another developed a contralateral posterior canal affectation. One of the patients maintained a persistent pDBN at 180 days despite the repeated maneuvers. CONCLUSIONS: Video-oculography demonstrates that anterior canal BPPV is characterized by a predominant downbeating nystagmus in response to DH. These individuals may show alterations in the vestibular caloric, and they can have multicanal affectation.