The Light Cupula: An Emerging New Concept for Positional Vertigo

Variants of posterior semicircular canal involvement in benign paroxysmal positional vertigo

Benign paroxysmal positional vertigo is the most common cause of peripheral vertigo. It is characterized by short and recurrent episodes of vertigo, trigged by specific head movements that displace otoconia within the semicircular canals. The movement of dislodge otoconia from the utricle cause abnormal positional endolymphatic currents. Primary treatment involves reposition maneuvers aimed at moving the displaced otoconia out the affected canal, therefore correct identification of the affected canal is essential for the diagnosis. The posterior semicircular canal (PSC) is the most frequently affected due to its spatial orientation and the force of gravity. Recent technological advances have allowed for better assessment of positional nystagmus during diagnostic and therapeutic maneuvers, revealing various possible scenarios of PSC involvement. Regarding the PSC, otoconia may be found in different parts of the canal, and not just in the expected location, floating in the long arm of the canal. The understanding of these variants is crucial, as the prognosis and the disease progression differ in such cases. This review aims to describe the six possible variants of PSC involvement described so far.

Clinical characteristics and lateralization of the horizontal semicircular canal light cupula

Introduction

Positional vertigo and nystagmus are the main symptoms and signs of dizziness, respectively. Despite the clinical utility of the supine roll test (SRT) and null point (NP) in diagnosing light cupula, a type of positional vertigo, there exists a notable gap in the literature concerning the comprehensive evaluation of lateralization values based on various nystagmus characteristics and the intensity of direction-changing positional nystagmus (DCPN) in the SRT, particularly in comparison to the NP. Additionally, limited data on abnormal canal paresis (CP) in light cupula patients underscores the need for further research with a larger patient population to elucidate this mechanism. This study aims to investigate the characteristics of positional nystagmus and lateralization of the horizontal semicircular canal (HSCC) light cupula, which is a type of positional vertigo and nystagmus that is poorly understood.

Methods

Eighty-five patients (17 males, 68 females; mean age, 60.9 years) with light cupula were reviewed. We summarized the characteristics of spontaneous nystagmus and positional nystagmus, including supine positioning nystagmus, bow nystagmus, and lean nystagmus. Then, the side of the NP was identified as the affected side, and the values of the fast phase direction of the spontaneous nystagmus, supine positioning nystagmus, bow nystagmus, and lean nystagmus, as well as the intensity of the DCPN in the SRT, were used to diagnose the affected sides. Caloric testing was also performed for some patients.

Results

Light cupula was observed in 5.7% of the patients with positional nystagmus. The frequencies of supine positioning nystagmus (88.2%), bow nystagmus (90.6%), and lean nystagmus (83.5%) were higher than spontaneous nystagmus (61.2%) (p < 0.001). The second NP (NP2) (92.9%) and third NP (NP3) (83.5%) were readily detected, affecting the left and right sides in 38 and 47 patients, respectively. Lateralization through the fast phase directions of bow nystagmus and lean nystagmus did not significantly differ from that of NP (all p > 0.05). However, the accuracy rate of lateralization through the sides with more vigorous DCPN in the SRT was 63.5%, significantly lower than through NP (p < 0.001). Particularly in patients with supine positioning nystagmus (n = 75), the rate was only 58.7% (p < 0.001). However, the rate was 100% in patients without supine positioning nystagmus (n = 10). Among the 70 patients who underwent caloric testing, 37 had abnormal CP, and the sides of the reduced caloric reaction were ipsilateral to the affected sides of the light cupula in 83.8% of the patients.

Conclusion

Besides utilizing the NP to determine the affected side, the fast phase direction of the bow nystagmus or lean nystagmus can also aid in identification. However, a simple comparison of the intensity of DCPN in SRT cannot provide accurate lateralization, especially in patients with supine positioning nystagmus. There is a high incidence of CP on the affected side of the light cupula.

Clinical Characteristics of persistent geotropic horizontal direction-changing positional nystagmus: Experience in 189 participants

BACKGROUND

The etiology and mechanism of persistent geotropic horizontal direction-changing positional nystagmus (DCPN) are still unclear. Whether this pattern of nystagmus is a subtype of benign paroxysmal positional vertigo (BPPV) remains controversial.

OBJECTIVE

The goal of this study was to observe the clinical characteristics of persistent geotropic horizontal DCPN involving the lateral semicircular canal.

METHODS

The analysis was performed to participants with episodic positional vertigo in our clinic from 2014 to 2021. Participants were included via positional test. We observed and summarized the distribution data, vertigo history, follow-up tests, and recurrence situations of 189 persistent geotropic horizontal DCPN participants.

RESULTS

The mean age at the first time showing of persistent geotropic horizontal DCPN was 56±14.7 and more women than men were affected by persistent geotropic horizontal DCPN (female-to-male ratio 2.4 : 1). Overall, 58.7% (57/94) of participants who came for the first-week follow-up test were asymptomatic. Thirty-three participants experienced recurrence (female-to-male ratio: 4.5 : 1). Fifty-three (28.0%) participants experienced the conversion of the patterns of DCPN in the history, the follow-up tests and the recurrence compared to the first showing of persistent geotropic horizontal DCPN. 24(12.1%) participants still experienced persistent geotropic horizontal DCPN attack in the follow-up tests and the recurrences without benign paroxysmal positional vertigo history.

CONCLUSION

Persistent geotropic horizontal DCPN affected more women than men. The persistent geotropic horizontal DCPN that with conversion to transient geotropic horizontal DCPN or to persistent apogeotropic horizontal DCPN might be a subtype of BPPV or in a stage of BPPV process. However, the persistent geotropic horizontal DCPN without conversion might be an independent disease that is not related to BPPV.

Light cupula phenomenon: a systematic review

Geotropic direction-changing positional nystagmus (DCPN) is transient in lateral semicircular canal (LSSK) canalolithiasis; it usually cuts off within a minute and fatigues. However, a “light cupula” mechanism has been described for patients with positional vertigo who exhibit a persistent geotropic DCPN without delay or fatigue. When the cupula becomes lighter than the surrounding endolymph, deflection may occur in the cupula under the influence of gravity. The person experiences dizziness and persistent positional nystagmus can be observed while remaining in that position.

In this review, studies investigating the “light cupula phenomenon,” which is a newly defined phenomenon in the literature, were compiled. A systematic literature search was conducted on the light cupula phenomenon in PubMed and Google Scholar databases to illuminate the clinical side of this new phenomenon and reveal its distinctive features. Turkish and English articles published between 2010 and 2021 were scanned; the thesis, reviews, and books were excluded from the study. Forty-eight articles were included in the study.

Mechanisms underlying light cupula has been explained as the “heavier endolymph hypothesis” with increased endolymph specific gravity due to an acute attack such as labyrinth hemorrhage, insufficient inner ear perfusion, or inflammation in the inner ear; “lighter cupula hypothesis” based on alcohol acting on the cupula earlier and making it lighter than the endolymph; “light particle hypothesis” due to the buoyancy of light debris, which are degenerative, swollen, and inflammatory cells in the endolymph adhering to the cupula and the “altered endolymph/perilymph density ratio hypothesis” that the difference in density between perilymph and endolymph causes light cupula. The pathophysiology of the light cupula phenomenon is still unclear, but it can be thought that all the different hypotheses may be effective in this phenomenon. Therefore, nystagmus characteristics and clinical course should be considered in patients for a more effective diagnosis and treatment process. In addition, the results of the studies show that light cupula may not be an uncommon disease and that some patients with geotropic DCPN can often be misdiagnosed as canalolithiasis LSCC-BPPV.

Direction-changing spontaneous nystagmus in patients with dizziness

PURPOSE

The present study aimed to investigate the clinical features of patients with direction-changing spontaneous nystagmus (DCSN) and gain insight into its underlying mechanisms.

METHODS

Medical records and vestibular function test results collected in our dizziness clinic between February 2013 and February 2020 were retrospectively reviewed. Spontaneous nystagmus was recorded while sitting upright using videonystagmography for 2 min to confirm the spontaneous changes in nystagmus direction. Causative disease diagnoses were based on the patients' clinical history, audiometry results, vestibular function tests, and imaging studies.

RESULTS

Of 4786 patients, DCSN was observed in 41 (0.86%). Causative disease diagnoses included vestibular neuritis (n = 9), lateral semicircular canal cupulopathy (n = 9), cerebellopontine angle tumor (n = 8), vestibular paroxysmia (n = 2), vestibular migraine (n = 2), vestibular nucleus infarction (n = 1), sudden sensorineural hearing loss with vertigo (n = 2), Meniere's disease (n = 2), Ramsay Hunt syndrome (n = 1), labyrinthine fistula due to middle ear cholesteatoma (n = 1), lateral semicircular canal dysplasia (n = 1), post tympanomastoidectomy dizziness (n = 1), and head trauma (n = 2).

CONCLUSIONS

Although the periodicity of DCSN could not be determined because of insufficiently long observation times, it was observed in various central and peripheral vestibulopathies. Careful examination of spontaneous nystagmus over a sufficient period may ensure the detection of DCSN when evaluating dizziness.

Less talked variants of benign paroxysmal positional vertigo

The diagnostic criteria were established for benign paroxysmal positional vertigo (BPPV), the most common vestibular disorder worldwide, by the Barany Society in 2015. This marked an important milestone in the diagnosis and treatment of BPPV. However, there still remain uncertainties and ambiguities regarding the clinical features and pathophysiology of BPPV, and its clinical variants. In this manuscript, we will discuss 1) the emerging and controversial syndromes of BPPV (i.e., canalolithiasis of the anterior canal, cupulolthiasis of the posterior canal, and lithiasis of multiple canals) with updates, 2) atypical nystagmus according to the canal involved (e.g., nystagmus induced by head position changes in the pitch plane in horizontal canal BPPV, and positional downbeat nystagmus in posterior canal BPPV), 3) persistent geotropic positional nystagmus. Consideration of these uncommon types and manifestations of BPPV would broaden our understanding of BPPV pathomechanisms and allow differentiation from central vertigo and nystagmus.

Analysis of the nystagmus characteristics of cupula diseases: A case report

INTRODUCTION

Clinically, there is a kind of patients with positional vertigo or dizziness, which occurs when they turn left or right, look down or up, lie down or sit up. With a long duration and varying frequency, it is not consistent with the manifestations of benign paroxysmal positional vertigo (BPPV). In addition, the persistent geotropic direction-changing positional nystagmus (PG-DCPN) was observed in a supine head-roll test.

PATIENT CONCERNS

With no apparent trigger for visual rotation and a sense of self instability, an 81-year-old female patient had suffered from vertigo for 3 days. The vertigo occurred every day, lasting several minutes each time, and associated with head movements and changes in body position. In a supine head-roll test, it appeared persistent geotropic direction-changing positional nystagmus for a long time, without latency, fatigability and in the presence of 3 zero planes.

DIAGNOSIS

Light cupula.

INTERVENTIONS

Difenidol hydrochloride 25 mg orally 3 times/day for 2 weeks and betahistine hydrochloride 12 mg orally 3 times/day for 1 month were administered.

OUTCOMES

After 1 month of treatment, the patient's vertigo symptoms disappeared. And in the supine head-roll test, the persistent geotropic direction-changing positional nystagmus disappeared.

CONCLUSION

We report the characteristics of nystagmus produced in a typical patient with light cupula during the supine head-roll test. After reviewing the relevant literatures, we believe that a simpler method can be used to identify canalolithiasis and cupula disease, to distinguish light and heavy cupula, and to determine the pathological semicircular canal to which the lesion belongs.

Immediate and short-term effects of Gufoni and Appiani liberatory maneuver for treatment of ageotropic horizontal canal benign paroxysmal positional vertigo: A prospective randomized trial

OBJECTIVE

To examine the treatment effects of repositioning maneuvers with the head turned 45° downwards (Gufoni maneuver) and 45° upwards (Appiani maneuver) in 25 patients with ageotropic horizontal semicircular canal (HSCC) benign paroxysmal positional vertigo (BPPV).

METHODS

Patients were randomly assigned to the Gufoni or Appiani maneuvers, and their immediate and short-term efficacy was investigated.

RESULTS

The immediate treatment response was successful in four of 16 patients who were treated with the Appiani maneuver and were not successful in any of the nine patients treated with the Gufoni maneuver. The patients who showed spontaneous resolution during follow-up outnumbered the patients who showed resolution of ageotropic HSCC BPPV immediately after the repositioning maneuvers.

CONCLUSION

This study showed a very low immediate resolution rate of ageotropic HSCC BPPV after the Gufoni maneuver; this may be attributed to the less effectiveness of the Gufoni maneuver against debris that often exists in the canal side of the cupula. Another interesting finding was that the rate of spontaneous resolution during the follow-up period was higher than that of immediate resolution after the repositioning maneuvers, which may support the recently proposed hypothesis that ageotropic positional nystagmus can also be evoked by causes other than the otolithic attachment on the cupula, such as a slight change in the biochemical composition of the inner ear fluids.

LEVEL OF EVIDENCE

3.

Lateral semicircular canal-BPPV: Prospective randomized study on the efficacy of four repositioning maneuvers

INTRODUCTION

Multiple repositioning maneuvers have been described to treat lateral semi-circular canal Benign Paroxysmal Positional Vertigo (LC-BPPV) patients. In this study, we compare efficacy of four therapeutic repositioning maneuvers for LC-BPPV patients and aim to identify clinical variables associated with persistent disease.

MATERIAL AND METHODS

A prospective study was conducted at a tertiary center, between January 2017 and September 2019. Patients diagnosed with LC-BPPV were randomly treated with Gufoni or barbecue-roll maneuvers (for the geotropic variant) and Gufoni-Appiani, barbecue-roll or Zuma-e-Maia maneuvers (for the apogeotropic form). Efficacy was compared and statistical analysis was performed to find clinical factors associated with no response.

RESULTS

Forty-eight patients and 82 maneuvers were included. Female patients and right side were more commonly affected. The mean age was 67 years. Seven cases (14.6%) resulted from a canal-switch. One single maneuver resolved 23 cases (47.9%) and the success rate rose to 75% at the end of the first visit (after up to 4 maneuvers) and to 93.8% after a-week of follow-up. Success rates were significantly better with Gufoni (68%) than with barbecue roll (34.8%; p=0.021) in geotropic LC-BPPV and better with Gufoni-Appiani (71.4%) than barbecue roll and Zuma-e-Maia maneuvers (33.3%; p=0.239) in apogeotropic LC-BPPV. Higher rates of persistent disease after first visit were found with older patients, left side and apogeotropic LC-BPPV and with longer latency and duration diagnostic nystagmus.

CONCLUSION

Our study suggests that Gufoni and Gufoni-Appiani maneuvers may be the most efficacious treatment for geotropic and apogeotropic LC-BPPV, respectively, compared to barbecue-roll and Zuma-e-Maia maneuvers.

Update on benign paroxysmal positional vertigo

Benign paroxysmal positional vertigo (BPPV) is the most common cause of vertigo worldwide. This review considers recent advances in the diagnosis and management of BPPV including the use of web-based technology and artificial intelligence as well as the evidence supporting the use of vitamin D supplements for patients with BPPV and subnormal serum vitamin D.

Light Cupula: To Be Or Not to Be?

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.

Direction-Changing Positional Nystagmus in Acute Otitis Media Complicated by Serous Labyrinthitis: New Insights into Positional Nystagmus

OBJECTIVE

To demonstrate characteristic nystagmus findings in acute otitis media (AOM) complicated by serous labyrinthitis and discuss the mechanism of direction-changing positional nystagmus (DCPN) in this condition.

PATIENTS

A patient with AOM complicated by serous labyrinthitis on the left side.

INTERVENTION

Video nystagmography and 3D fluid attenuated inversion recovery (FLAIR) magnetic resonance imaging (MRI).

MAIN OUTCOME MEASURES

Characterize positional nystagmus in a head-roll test observing the change of nystagmus direction in process of time and compare findings of temporal bone 3D FLAIR MRI.

RESULTS

A previously healthy 50-year-old man who complained of acute otalgia, hearing loss, and vertigo was diagnosed with AOM complicated by serous labyrinthitis on the left side. A head-roll test performed on the day when vertigo developed showed persistent geotropic DCPN. While pre- and postcontrast T1-weighted MRI showed no signal abnormality in both inner ears, 10-minute delay postcontrast 3D FLAIR image showed enhancement in the inner ear on the left side. Four-hour-delay postcontrast 3D FLAIR images showed more conspicuous enhancement of the whole cochlea, vestibule, and semicircular canals on the left side.

CONCLUSIONS

In AOM complicated by serous labyrinthitis, density of perilymph may increase due to direct penetration of cytokines and other inflammatory mediators from the middle ear into perilymph and breakdown of blood-labyrinth barrier that causes vascular leakage of serum albumin into perilymph. The density difference between perilymph and endolymph makes the semicircular canal gravity sensitive. A buoyant force is also generated by gravity, causing indentation of endolymphatic membrane in the ampulla and cupula displacement. Thus, at the early stage of serous labyrinthitis, a head-roll test may elicit persistent geotropic DCPN, of which the direction can be changed over time.

Comorbid Cupulolithiasis Is Rare in Patients With Horizontal Semicircular Canal Canalolithiasis

OBJECTIVES

Considering that otolith particles pass through the canal until attaching to the cupula in the canal-side horizontal semicircular canal (HSCC) cupulolithiasis, comorbidity of HSCC canalolithiasis and cupulolithiasis may occur. We aimed to investigate the incidence of comorbidity of cupulolithiasis in patients with HSCC canalolithiasis and to improve treatment efficacy.

STUDY DESIGN

Retrospective study.

SETTING

Tertiary referral academic center.

PATIENTS

Ninety-seven consecutive patients with HSCC canalolithiasis between March 2017 and March 2019 were included.

MAIN OUTCOME MEASURES

Coexistence of HSCC cupulolithiasis was hierarchically investigated. 1) Spontaneous reversal of initial nystagmus is observed bilaterally in a head-roll test (HRT), 2) nystagmus is in the same direction at each of the three times the supine position was tested, and 3) both bowing and leaning nystagmus with opposite direction are observed.

RESULTS

Of 97 patients with HSCC canalolithiasis, 2 patients (2%) had comorbid HSCC cupulolithiasis.

CONCLUSIONS

Although coexistence of HSCC canalolithiasis and cupulolithiasis should be considered when spontaneous reversal of nystagmus direction is observed without position change during a HRT, the incidence of coexistence is very low. However, canalith repositioning maneuvers for both canalolithiasis and cupulolithiasis should be performed in cases with comorbidity.

A new treatment (the affected-ear-up 90° maneuver) for benign paroxysmal positional vertigo of the lateral semicircular canal

Background: Although several researchers have tried various kinds of canalith repositioning procedures for lateral canalolithiasis, a standard treatment has not been established. We have adopted 90° rotation, which is anatomically appropriate. Objective: To clarify the efficacy of the affected-ear-up 90° maneuver. Materials and methods: The subjects were 23 consecutive patients (15 females, 8 males) who revealed transient direction-changing geotropic positional nystagmus. After determining the affected side, we immediately performed the canalith repositioning procedure. To perform this maneuver: (1) Place the patient in the supine position. (2) Rotate the head toward the healthy side until 90° from the supine. (3) Sit up. (4) Ask the patient to remain upright with the chin down until going to bed. Results: Nineteen patients (83%) became symptom-free by only one maneuver. However, three patients converted to ipsilateral cupulolithiasis of the lateral canal, and one patient required a second maneuver. Conclusion: The affected-ear-up 90° maneuver is effective against lateral canalolithiasis.

Central positional nystagmus: Characteristics and model-based explanations

The central vestibular system operates to precisely estimate the rotational velocity and gravity orientation using the inherently ambiguous information from peripheral vestibular system. Therefore, any lesions disrupting this function can generate positional nystagmus. Central positional nystagmus (CPN) can be classified into the paroxysmal (transient) and persistent forms. The paroxysmal CPN has the features suggesting a semicircular canal origin regarding the latency, duration, and direction of nystagmus. Patients with paroxysmal CPN commonly show several different types of nystagmus classified according to the provoking positioning. The persistent form of CPN mostly appears as downbeat nystagmus while prone or supine, or apogeotropic or geotropic horizontal nystagmus when the head is turned to either side while supine. CPN may be ascribed to erroneous neural processing within the velocity-storage circuit that functions in estimating angular head velocity, gravity direction, and inertia. Paroxysmal CPN appears to be post-rotatory rebound nystagmus due to lesions involving the cerebellar nodulus and uvula. In contrast, persistent CPN may arise from erroneous gravity estimation. The overlap of lesion location responsible for both paroxysmal and persistent CPN may account for the frequent coexistence of both forms of nystagmus in a single patient.

Density difference between perilymph and endolymph: A new hypothesis for light cupula phenomenon

Light cupula is an emerging concept accounting for positional nystagmus. It can be diagnosed when persistent geotropic direction-changing positional nystagmus (PG DCPN) is observed in a head-roll test. Although hypotheses explaining light cupula phenomenon such as "light debris", "lighter cupula", and "heavier endolymph" have been proposed, the mechanism underlying light cupula has not been clearly elucidated yet. In the present study, we proposed a new hypothesis accounting for light cupula, i.e., density difference between perilymph and endolymph could elicit characteristic PG DCPN in a head-roll test. We also discussed the mechanism how membranous canal containing endolymph became buoyant within the perilymphatic space under constant influence of gravity when the density of perilymph was higher than that of endolymph.

Benign paroxysmal positional vertigo in the elderly: current insights

Balance disorders, unsteadiness, dizziness and vertigo in the elderly are a significant health problem, needing appropriate treatment. One third of elderly patients with vertigo were diagnosed with benign paroxysmal positional vertigo (BPPV), the most common cause of dizziness in both primary care specialist Neurology and Ear Nose Throat settings. BPPV presents a specific paroxysmal positional nystagmus which can be obtained using the appropriate diagnostic positional test and can be treated effectively using specific therapeutic maneuvers. This review presents current insights into the diagnostic, pathogenetic and therapeutic aspects of BPPV in the elderly. BPPV in older patients does not differ significantly from BPPV in younger patients, with regard to pathogenesis, diagnosis and treatment. However, in older patients, its prevalence is higher and it responds less effectively to treatment, having a tendency for recurrence. Specific issues which should be considered in the elderly are: 1) difficulty in obtaining an accurate history; 2) difficulty in performing the diagnostic and therapeutic maneuvers, which should be executed with slow and gentle movements and extremely cautiously to avoid any vascular or orthopedic complications; and 3) the relation between BPPV and falls.

The effective clinical outcomes of the Gufoni maneuver used to treat 91 vertigo patients with apogeotropic direction-changing positional nystagmus (apo-DCPN)

This study aimed to observe and analyze the effects and outcomes of patients with apogeotropic direction-changing positional nystagmus (apo-DCPN) who received Gufoni maneuver.A total of 91 patients with positional vertigo admitted to the specialized dizziness clinic in Zhejiang Provincial People's Hospital from February 2014 to August 2017 were included. The immediate treatment responses to the Gufoni maneuver were observed and recorded. The patients in whom the treatment was ineffective were followed up for 4 weeks to observe the outcome of apo-DCPN.In 21 patients, the apo-DCPN was transformed after Gufoni maneuver, and 7 patients developed transformation within 4 weeks of follow-up. Spontaneous remission of apo-DCPN within the follow-up period was observed in 55 patients who were unresponsive to the Gufoni maneuver. The prevalence of migraine was significantly higher in the early remission group (P < .05) and the period between the initial visit and nystagmus remission was significantly shorter in the group of patients with migraine history (P < .05).This study demonstrates that the immediate treatment efficacy of the Gufoni maneuver is poor in positional vertigo patients with apo-DCPN. We believe that the reason for the low efficacy is that the Gufoni maneuver is only effective for some patients with apo-DCPN type HSC-BPPV. In patients with early spontaneous remission and a history of migraine, central positional nystagmus of probable vestibular migraine (VM) or benign recurrent vertigo should be considered for the mechanisms of apo-DCPN generation.

Effect of intratympanic steroid injection in light cupula

OBJECTIVE

To evaluate the effects of intratympanic steroid injection (ITS) in light cupula.

METHODS

A total of 47 patients showing persistent geotropic direction-changing positional nystagmus with null point (light cupula) were randomly classified into three groups: ITS (n = 15), vestibular suppressant (VS, n = 16) and canalith repositioning procedure (CRP, n = 16). Positional nystagmus and dizziness severity by dizziness handicap inventory (DHI) and visual analogue scale (VAS) were conducted before and 3 d and 1 week after first treatment to compare the effect of each treatment.

RESULTS

DHI and VAS scores had decreased after each treatment; however, there were no differences among the three groups. A week after the first treatment, 7, 6 and 7 patients showed resolution of direction-changing positional nystagmus (DCPN) in the ITS, CRP and VS groups, respectively. There were no significant differences between the three groups. In the ITS group only, however, reversal of the stronger side on head roll test was observed in 6 patients, and 2 of them showed resolution of DCPN at the third day.

CONCLUSIONS

ITS was not effective for patients with light cupula at 1-week follow-up. However, some patients in the ITS group showed resolution of DCPN at earlier follow-up.