Clinical characteristics of patients with multi-canal benign paroxysmal positional vertigo

IntroductionMulti-canal benign paroxysmal positional vertigo is considered to be a rare and controversial type in the new diagnostic guidelines of Bárány because the nystagmus is more complicated or atypical, which is worthy of further study.ObjectiveBased on the diagnostic criteria for multi-canal benign paroxysmal positional vertigo proposed by International Bárány Society, the study aimed to investigate the clinical characteristics, diagnosis and treatment of multi-canal benign paroxysmal positional vertigo.MethodsA total of 41 patients with multi-canal benign paroxysmal positional vertigo were included and diagnosed by Roll, Dix-Hallpike and straight head hanging tests. Manual reduction was performed according to the involvement of semicircular canals.ResultsAmong the 41 cases, 19 (46.3%) patients showed vertical up-beating nystagmus with or without torsional component and geotropic, apogeotropic horizontal nystagmus, and were diagnosed with posterior-horizontal canal. 11 (26.8%) patients showed vertical up-beating nystagmus with torsional component on one side and vertical down-beating nystagmus with or without torsional component on the other side during Dix-Hallpike test or straight head hanging test and were diagnosed with posterior-anterior canal benign paroxysmal positional vertigo 9 (26.8%) patients showed vertical down-beating nystagmus with or without torsional component and geotropic, apogeotropic horizontal nystagmus, and were diagnosed with anterior-horizontal canal 2 (4.9%) patients showed vertical geotropic torsional up-beating nystagmus on both sides and were diagnosed with bilateral posterior canal benign paroxysmal positional vertigo. High correlation between the sides with reduced vestibular function or hearing loss and the side affected by Multi-canal benign paroxysmal positional vertigo was revealed (contingency coefficient = 0.602, p = 0.010). During one-week follow up, nystagmus/vertigo has been significantly alleviated or disappeared in 87.8% (36/41) patients.ConclusionPosterior-horizontal canal benign paroxysmal positional vertigo was the most common type. Multi-canal benign paroxysmal positional vertigo involving anterior canal was also not uncommon. Caloric tests and pure tone audiometry may help in the determination of the affected side. Manual reduction was effective in most of Multi-canal benign paroxysmal positional vertigo patients.     

Conversion of canalolithiasis to cupulolithiasis in the course of a horizontal benign paroxysmal positional vertigo case

The benign paroxysmal positional vertigo of the horizontal semicircular canal is manifested with either geotropic or apogeotropic horizontal nystagmus. A 61-year-old male patient who experienced repeated episodes of positional vertigo is presented in this study. The vertigo was reported to be more severe while rotating his head to the left and then to the right. The initial examination revealed a geotropic purely horizontal nystagmus at the lateral positions of the head compatible with canalolithiasis of the left horizontal semicircular canal. In this case, the otoconia debris migrates from the vestibule into the horizontal semicircular canal through its nonampullary end, where they float freely (canalolithiasis). Five days later, the geotropic nystagmus transformed to apogeotropic. Thus, it may be assumed that the otoconia debris adhered to the cupula and converted the canalolithiasis to cupulolithiasis of the horizontal semicircular canal on the same side. With rotation of the head to the left while the patient was in the supine position, gravity causes the weighted cupula to deflect ampullofugally, resulting in apogeotropic nystagmus; the opposite was noticed when the head was rotated to the right. The so-called barbecue maneuver was initially effective curing the geotropic form of the condition and consequently the modified Semont maneuver for the apogeotropic form.     

Value of lying-down nystagmus in the lateralization of horizontal semicircular canal benign paroxysmal positional vertigo.

BACKGROUND: Horizontal canal benign paroxysmal positional vertigo is characterized by horizontal direction-changing nystagmus induced by lateral head turning in supine position. According to Ewald's second law, the direction of head turning that creates a stronger response represents the affected side in geotropic nystagmus and the healthy side in apogeotropic nystagmus. However, it may not always be possible to lateralize the involved ear only by comparing the intensity of the nystagmus. We studied the values of nystagmus induced by position change from sitting to supine in the lateralization of horizontal canal benign paroxysmal positional vertigo. METHODS: A retrospective study of 54 patients who had been diagnosed as having horizontal canal benign paroxysmal positional vertigo at the Dizziness Clinic of Seoul National University Bundang Hospital from May 2003 to February 2004 was performed. The directions of the nystagmus induced by lying down were compared with those determined by Ewald's second law. RESULTS: Of the 54 patients, 32 (20 apogeotropic and 12 geotropic) showed horizontal nystagmus induced by lying down. The nystagmus tended to be ipsilesional in apogeotropic patients (80%) and contralesional in their geotropic counterparts (75%). CONCLUSION: In horizontal canal benign paroxysmal positional vertigo, lying-down nystagmus mostly beats toward the involved ear in the apogeotropic type and directs to the healthy ear in the geotropic type. The direction of lying-down nystagmus may help lateralizing the involved ear in horizontal canal benign paroxysmal positional vertigo.     

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.     

The treatment of horizontal canal positional vertigo: our experience in 66 cases.

OBJECTIVES/HYPOTHESIS: The horizontal semicircular canal variant of paroxysmal positional vertigo (HSC-PPV) shows three subtype nystagmic patterns: 1) bilateral geotropic nystagmus, 2) bilateral apogeotropic nystagmus that may switch into bilateral geotropic, and 3) bilateral apogeotropic nystagmus that never switches into bilateral geotropic. In recent years, many methods of physical treatment have been proposed for HSC-PPV, yet no standard protocol has been defined. We studied the effects of different methods according to each different form of HSC-PPV after a precise definition of the nystagmic and clinical features. STUDY DESIGN: A prospective trial of 66 patients with horizontal canal paroxysmal positional vertigo treated with a combination of rotational maneuver and forced prolonged position. METHODS: We evaluated 66 patients with HSC-PPV in its three subtypes. For patients with bilateral geotropic nystagmus, the "barbecue" method was combined with "forced prolonged position." Patients with bilateral geotropic nystagmus were submitted to maneuvers aimed at a switch to bilateral geotropic. The cases that did not switch were submitted to a modified fourth step of the Semont maneuver. RESULTS: Eighty percent of the patients with bilateral geotropic nystagmus became symptom free within the second session, and in 90% of the patients, symptoms were resolved by the third session. In the bilateral apogeotropic cases, the modified fourth step of the Semont maneuver resulted in 75% of the patients being symptom free. CONCLUSIONS: The correct identification of both nystagmic pattern and site of the lesion is crucial for the choice of physical treatment of HSC-PPV and its success. We have standardized the treatment protocol consisting of a "barbecue" maneuver followed by "forced prolonged position" in cases of geotropic nystagmus and a modified fourth step of the Semont maneuver for apogeotropic nystagmus. Our results appear encouraging because 90% of the entire study group was symptom free after three sessions.     

Walk-rotate-walk test identifies patients responding to Lempert’s maneuver, with benign paroxysmal positional vertigo of the horizontal canal

Two hundred and fifteen patients were diagnosed and treated for benign paroxysmal positional vertigo of the horizontal canal (BPPV-HC). All patients were tested with conventional positional nystagmus tests lying supine and rotating head for geotropic nystagmus, registered with Frenzels glasses, and in 109 cases with ENG. The walk-rotate-walk (WRW) test, developed by one of us (T.R.) and described in the text, was applied to all patients. The immediate good treatment results with Lempert’s maneuver verify the correct diagnosis of BPPV-HC. The WRW test is a more sensitive test for BPPV-HC than earlier positional tests. The unhabituated acute phase of vestibular neuritis shows positive test results and must be eliminated with caloric tests. The WRW test identifies as a dynamic test patients with symptoms of even lesser magnitude, where the compensatory capacity of the equilibrium system suppresses the diagnostic findings with earlier positional horizontal canal tests. Received: 14 December 2000 / Accepted: 5 February 2001     

Repositioning maneuver for the treatment of the apogeotropic variant of horizontal canal benign paroxysmal positional vertigo.

OBJECTIVE: The purpose of this study was to determine the effectiveness of a new physical maneuver in the treatment of the apogeotropic variant of horizontal canal benign paroxysmal positional vertigo. STUDY DESIGN: Case review. SETTING: Outpatient clinic. PATIENTS: The diagnosis of apogeotropic horizontal canal benign paroxysmal positional vertigo was based on the history of recurrent sudden crisis of vertigo associated with bursts of horizontal apogeotropic paroxysmal nystagmus provoked by turning the head from the supine to either lateral position. The patients were three men and five women ranging in age from 31 to 73 years (average, 49.2 yr). INTERVENTIONS: All patients were treated with a repositioning maneuver based on the hypothesis that the syndrome is caused by the presence of free-floating dense particles inside the endolymph of the anterior arm of the horizontal canal. The maneuver favors their shifting into the posterior arm of the canal. Patients were reexamined immediately after the treatment and underwent Gufoni's liberatory maneuver for the geotropic variant of horizontal canal benign paroxysmal positional vertigo. MAIN OUTCOME MEASURE: The treatment outcome was considered as responsive when, after one repositioning maneuver, nystagmus shifted from apogeotropic to geotropic. RESULTS: The repositioning maneuver resulted in a transformation from the apogeotropic variant into a geotropic variant of horizontal canal benign paroxysmal positional vertigo in all patients. CONCLUSION: This maneuver represents a simple and effective approach to the treatment of the apogeotropic variant of horizontal canal benign paroxysmal positional vertigo. It favors the shifting of the canaliths from the anterior into the posterior arm of the horizontal canal from where they can migrate into the utricle with Gufoni's maneuver.     

Benign paroxysmal positional vertigo due to a simultaneous involvement of both horizontal and posterior semicircular canals

From April 2001 to November 2003, we investigated 8 patients with benign paroxysmal positional vertigo (BPPV) that was suspected to simultaneously affect both the horizontal and posterior semicircular canals (HSCC and PSCC). These cases showed typical vertical-torsional nystagmus induced by the Dix-Hallpike maneuver, followed by a horizontal nystagmus. They also showed a direction-changing geotropic or apogeotropic positional nystagmus triggered by lateral head rotations in the supine position. Using the three-dimensional analysis of the positional nystagmus, the rotation axis of the positional nystagmus had a component perpendicular to the plane of PSCC and another component perpendicular to the plane of HSCC. All these findings suggest that BPPV in these patients was a combination of posterior and horizontal canal BPPV. The observation of a vertical-torsional positional nystagmus should prompt the specialist to perform not only the canalith repositioning procedure, but also to execute lateral head turns in the supine position.     

离地性眼震水平半规管BPPV诊治策略

目的 探讨离地性眼震水平半规管良性阵发性位置性眩晕(HC-BPPV)的诊治策略.方法 回顾性分析2017年7月～2019年6月确诊的48例离地性眼震HC-BPPV患者的临床资料,均采用滚转试验(roll test)、低头仰头试验(bow and lean test)等方法判断侧别,通过Gufoni法、Barbecue法...     

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．     

Square wave manoeuvre for apogeotropic variant of horizontal canal benign paroxysmal positional vertigo in neck restricted patients

Objective:We aimed to describe the clinical features of the apogeotropic variant of horizontal canal benign paroxysmal positional vertigo(HC BPPV-AG)in a cluster of patients with restrictive neck movement disorders and a new therapeutic manoeuvre for its management.Methods:In a retrospective review of cases from an ambulatory tertiary referral center,patients with HC BPPV-AG in combination with neck movement restriction that prevented any classical manual repositioning procedure or who were refractory to canalith repositioning manoeuvres,were treated with a new manoeuvre comprised of sequential square-wave pattern of head and body supine rotations while nystagmus was being monitored,until either an apogeotropic to geotropic conversion or resolution of the nystagmus was observed.Results:Fifteen patients were studied.All but one[14/15 cases]showed a positive therapeutic response to the repositioning procedure in a single session.In two cases,a direct relief of vertigo and elimination of nystagmus was observed without an intermediate geotropic phase.Although in three patients the affected ear was not initially identified,it was ultimately identified and successfully treated by the square wave manoeuvre in all of them.Conclusions:The square-wave manoeuvre is an alternative for HC BPPV-AG treatment in either cases with neck restriction,where the affected side is not well identified at the bedside or when other manoeuvres fail to resolve the HC BPPV-AG.     

Benign paroxysmal vertigo of the horizontal canal

Over a period of 4 years we observed 15 cases of benign positional vertigo (BPV) probably caused by deposition of otoliths in the horizontal semicircular canal. Rapid rolling onto one side in recumbent position provokes a paroxysmal, purely horizontal and geotropic nystagmus which nearly always spontaneously inverts direction. Rolling the patient onto the other side provokes a left intense geotropic nystagmus. BPV is more violent but resolves more rapidly than that of the better known posterior canal positional vertigo. Sometimes both syndromes are present together.     

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.     

水平背地性眼震良性阵发性位置性眩晕的诊断和手法复位

目的：验证一种新的用于治疗水平背地性眼震良性阵发性位置性眩晕（apogeotropicHSC—BPPV）的手法复位方法。方法：该研究采取改良的SupineRollTest（M-RollTest）方法共诊断出l78例水平半规管良性阵发性位置性眩晕（HSC-BPPV）患者,其中37例apogeotropicHSC—BPPV纳入该研究样本,占发病数的20．79％。采用管石重置手法先将37例apogeotropicHSC—BPPV患者水平背地性眼震转变为水平向地性眼震;此后,施行传统barbecue法进行手法复位。管石重置手法如下：①患者取仰卧头垫高30°体位静卧;②10min后头快速向患侧转90°;③2min后头向中线回旋45°;④保持体位2min后患者恢复仰卧头高30°体位;静卧10min后,采用M—RollTest检查验证患者是否出现双侧水平向地性眼震。如管石重置失败,重复以上手法多次,直至出现双侧水平向地性眼震为止。结果：36例双侧水平背地性眼震经水平背地性眼震管石重置手法全部转变为双侧不同强度的水平向地性眼震,其中,18例经1次,11例经2次,4例经3次,3例经4～6次。1例经1次管石重置手法后自觉症状减轻,再次行M—RollTest检查证明水平眼震消失,但Dix-hallpike手法复位检查出现同侧上跳性扭转性眼震,确诊为同侧后半规管良性阵发性位置性眩晕（PSC-BPPV）。该组管石重置成功率为为97．3％。36例HSC—BPPV患者经barbecue法手法复位全部一次性获得成功,1例PSC—BPPV患者经Eptey管石复位法一次性获得成功。结论：该研究设计的水平背地性管石重置手法是治疗apogeotropicHSC—BPPV的必要手段,简便易学、成功率高,患者舒适度好,相对依从性高。     

Sudden sensorineural hearing loss with positional vertigo: Initial findings of positional nystagmus and hearing outcomes

Objectives: To investigate the initial findings of positional nystagmus in patients with sudden sensorineural hearing loss (SSNHL) and positional vertigo, and to compare hearing improvement among patients with different types of positional nystagmus. Design: The characteristics of positional nystagmus upon initial examination were analysed, and the initial mean pure-tone audiometry (PTA) threshold was compared with that at three months after treatment. Study sample: Forty-four SSNHL patients with concomitant positional vertigo were included. Results: Positional nystagmus was classified into five subgroups; persistent geotropic direction-changing positional nystagmus (DCPN) in head-roll test (HRT) and negative Dix-Hallpike test (DHT), persistent apogeotropic DCPN in HRT and negative DHT, positive DHT and negative HRT, persistent geotropic DCPN in HRT and positive DHT, and persistent apogeotropic DCPN in HRT and positive DHT. PTA threshold improvement was significantly greater in SSNHL patients with negative DHT than with positive DHT (p?=?0.027). Conclusions: When geotropic DCPN was elicited by HRT, the nystagmus was persistent, which suggests that alteration of specific gravity of the endolymph, rather than the lateral canal canalolithiasis, may be a cause of this characteristic positional nystagmus. Positive DTH may be a prognostic factor for worse hearing recovery among patients with SSNHL and positional vertigo.     

Dynamics of the vestibulo-ocular reflex in patients with the horizontal semicircular canal variant of benign paroxysmal positional vertigo

Objective Two types of direction-changing positional nystagmus, the geotropic and apogeotropic variants, are observed in patients with the horizontal semicircular canal (HSCC) type of benign paroxysmal positional vertigo (H-BPPV). In this study, we assessed the dynamics of the vestibulo-ocular reflex (VOR) of the HSCC in patients with H-BPPV.

Material and Methods Patients were rotated about the earth-vertical axis at frequencies of 0.1, 0.3, 0.5, 0.7 and 1.0 Hz with a maximum angular velocity of 50°/s. Eye movements were recorded on a video imaging system using an infrared charge-coupled device (CCD) camera, and our new technique for analyzing the rotation vector of eye movements in three dimensions was used.

Results In the patients with geotropic positional nystagmus, there were no differences in VOR gain between rotation to the affected and unaffected sides at frequencies of 0.1–1.0 Hz. Although no differences in VOR gain at frequencies of 0.3–1.0 Hz were noticed in patients with apogeotropic positional nystagmus, the VOR gain at 0.1 Hz was significantly smaller on rotation to the affected compared to the unaffected side.

Conclusion The results indicate that cupulolithiasis in the HSCC affected the dynamics of the HSCC-ocular reflex at 0.1 Hz, but not at higher frequencies, and that canalolithiasis in the HSCC does not change the VOR gain of the HSCC at any frequency. It is suggested that cupulolithiasis causes transient impairment of HSCC function by means of its mechanical restriction of movements of the cupula.     

Natural course of positional vertigo in patients with apogeotropic variant of horizontal canal benign paroxysmal positional vertigo

Objective

The purpose of this study was to assess the natural course of positional vertigo in patients with the apogeotropic variant of horizontal canal type of benign paroxysmal positional vertigo (AH-BPPV), which is reported to be more refractory to physiotherapy than the geotropic variant of horizontal canal type of BPPV (GH-BPPV).

Methods

14 patients with AH-BPPV treated without physiotherapy were asked to visit the hospital every 2 weeks. At every follow-up visit, they were interviewed and positional nystagmus was assessed. After the disappearance of positional nystagmus, patients were asked about the time of cessation of the positional vertigo. Thus, the primary outcomes were evaluated by the self-reported onset and remission of positional vertigo. The time course of remission of positional vertigo was then calculated.

Results

The average and median period from the onset to natural remission of positional vertigo in patients with AH-BPPV was 13 and 7 days, respectively.

Conclusion

We have already reported that the average and median period from the onset to natural remission of positional vertigo in patients with GH-BPPV was 16 and 7 days, respectively (Imai et al., 2005 [8]). Thus, the natural course of AH-BPPV is not as refractory as that of GH-BPPV.     

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.     

Benign paroxysmal positional vertigo showing sequential translations of four types of nystagmus

Objective

We report a case of benign paroxysmal positional vertigo (BPPV) showing sequential translation of four types of nystagmus and discuss its pathophysiology.

Methods

The case was 65-year-old female. We analyzed her nystagmus three-dimensionally.

Results

At the first visit, she showed vertical-torsio nystagmus of the posterior canal type of BPPV (P-BPPV) and subsequently showed recently reported geotropic nystagmus with a long time constant. Two weeks later, she showed apogeotropic nystagmus of the horizontal canal type of BPPV (AH-BPPV) and subsequently a geotropic nystagmus with a short time constant of the horizontal canal type of BPPV (GH-BPPV).

Conclusions

Three kind of nystagmus, namely P-BPPV, AH-BPPV and GH-BPPV can be explained by the otoconial debris hypothesis of the same ear. Finally, the recently reported geotropic nystagmus with a long time constant may be explained by a reversible lesion such as the denatured cupula or utricular imbalance of the same ear.     

Office-based differential diagnosis of transient and persistent geotropic positional nystagmus in patients with horizontal canal type of benign paroxysmal positional vertigo

Conclusion: A 30?s observation of geotropic positional nystagmus is sufficient to distinguish persistent geotropic positional nystagmus (PGPN) from transient geotropic positional nystagmus (TGPN) in patients with horizontal canal type of benign paroxysmal positional vertigo (H-BPPV) in ENT office.

Objective: As a canalith repositioning procedure effectively treats H-BPPV with TGPN, but not PGPN, the differentiation between patients with PGPN and with TGPN is essential. The purpose of this study is to determine the observation period enough to distinguish TGPN from PGPN.

Methods: This study first analyzed positional nystagmus images recorded with an infrared CCD camera three-dimensionally in 47 patients with H-BPPV. PGPN is distinguished from TGPN in patients with H-BPPV precisely by means of time constant calculated form analysis of positional nystagmus. Ten-second and 30-s movies were made of positional nystagmus of the all 47 patients. Ten independent otolaryngologists were then asked to distinguish TGPN from PGPN after a 10?s or 30?s observation of the geotropic positional nystagmus images in 47 patients with H-BPPV.

Results: The sensitivity and specificity to distinguish TGPN from PGPN was 100% and 97% after 30?s observation, but 100% and 40% after 10?s observation, respectively.