Direction-changing Positional Nystagmus Research Articles

Evaluation of the reliability and validity of the upright head roll test for lateral semicircular canal benign paroxysmal positional vertigo.

The upright head roll test (UHRT) is a recently introduced diagnostic maneuver for lateral semicircular canal benign paroxysmal positional vertigo (LSC-BPPV). This study aimed to evaluate the reliability and validity of the UHRT. Two separate studies were conducted. Study 1 analyzed 827 results of videonystagmography (VNG) to assess UHRT reliability, and Study 2 analyzed 130 LSC-BPPV cases to evaluate UHRT validity. The inter-test reliability between UHRT and the supine head roll test (SHRT) showed substantial agreement (Cohen's kappa = 0.753) in direction-changing positional nystagmus (DCPN) and almost perfect agreement (Cohen's kappa = 0.836) in distinguishing the direction of DCPN. The validity assessment of UHRT showed high accuracy in diagnosing LSC-BPPV (80.0%) and in differentiating the variant types (74.6%). UHRT was highly accurate in diagnosing the canalolithiasis type in LSC-BPPV patients (Cohen's kappa = 0.835); however, it showed only moderate accuracy in diagnosing the cupulolithiasis type (Cohen's kappa = 0.415). The intensity of nystagmus in UHRT was relatively weaker than that in SHRT (P < 0.05). UHRT is a reliable test for diagnosing LSC-BPPV and distinguishing subtypes. However, UHRT has a limitation in discriminating the affected side owing to a weaker intensity of nystagmus than SHRT.

Clinical characteristics and lateralization of the horizontal semicircular canal light cupula.

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. 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. 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. 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.

The Light Cupula Phenomenon: A Scoping Review.

Direction-changing positional nystagmus (DCPN), which refers to the change in the direction of nystagmus with different head positions, is a well-known characteristic of horizontal semicircular canal BPPV. The supine head roll test is commonly used to diagnose horizontal canal BPPV. However, persistent geotropic DCPN observed during this test cannot be explained by the conventional explanations of canalolithiasis or cupulolithiasis. To account for this unique nystagmus, the concept of a "light cupula" has been recently introduced. In this review, we provide an overview of the historical background, clinical features and diagnostic methods, proposed mechanisms, and treatment strategies associated with the light cupula phenomenon based on the available literature to date.

Pathological Study of Light Cupula Syndrome on a Visual Bionic Semicircular Canal.

A type of persistent direction-changing positional nystagmus with a null point during head position deflection is known as light cupula syndrome (LCS) in the clinic. To date, the pathogenesis and biomechanical response of human semicircular canals with light cupula syndrome (LCS) (HSCs-LCS) are still unclear. In this study, based on the anatomical structure and size of the one-dimensional human semicircular canal (HSC) and imitating the pathological changes of the endolymph in HSC with LCS, a visual bionic semicircular canal (BSC) with LCS was fabricated using three-dimensional printing technology, hydrogel modification, and target tracking technology. Through theoretical derivation, mathematical models of the HSC-LCS perception process were established. By conducting in vitro experiments on the bionic model, the biomechanical response process of HSC-LCS was studied, and the mathematical models were validated. The results of pulse acceleration stimulation showed that the pathological changes in the density and viscosity of the endolymph could reduce the deformation of the cupula of the BSC-LCS and increase the time constant. The results of the sinusoidal acceleration stimulation showed that the amplitude-frequency gain of the BSC-LCS decreased and the phase difference increased. The BSC-LCS can be used as a tool for pathological research of the HSC-LCS. The results of this study can provide a theoretical basis for clinical diagnosis.

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

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

Benign paroxysmal positional vertigo (BPPV) is the most common cause of positional vertigo and nystagmus. Direction-changing positional nystagmus (DCPN), which refers to the change in the direction of nystagmus with different head positions, is a well-known characteristic of horizontal semicircular canal BPPV. The supine head roll test is commonly used to diagnose horizontal canal BPPV. However, persistent geotropic DCPN observed during this test cannot be explained by conventional mechanisms of canalolithiasis or cupulolithiasis. The concept of a “light cupula” has been proposed to account for this unique nystagmus. In this review, we summarize the historical background, clinical features and diagnostic methods, presumed mechanisms, and treatment approaches of the light cupula phenomenon based on the available literatures up to date.

Treating benign paroxysmal positional vertigo of the lateral semicircular canal with a shortened forced position.

Benign paroxysmal positional vertigo (BPPV) is the peripheral vestibular disorder that is most frequently encountered in routine neuro-otological practice. Among the three semicircular canals, the lateral semicircular canal (LSC) is the second most frequently interested in the pathological process. In most cases, LSC BPPV is attributable to a canalithiasis or cupulolithiasis mechanism. The clinical picture of LSC BPPV is that of positional nystagmus and vertigo evoked by turning the head from the supine to the side lateral position. With such a movement, a horizontal positional (and often also paroxysmal) direction-changing nystagmus is generated. Depending on whether the pathogenetic mechanism is that of canalithiasis or cupulolithiasis and depending on where the dense particles are located, LSC BPPV direction-changing positional nystagmus is geotropic or apogeotropic on both lateral sides. Due to its mechanical nature, BPPV is effectively treated by means of physical therapy. In the case of a LSC BPPV, one of the most effective therapies is the forced prolonged position (FPP), in which the patient is invited to lie for 12 h on the lateral side on which vertigo and nystagmus are less intense, to move the canaliths out from the canal (or to shift them inside of the canal from one tract to another) exploiting the force of gravity. Despite its efficacy, FPP is not always well tolerated by every patient, and it cannot be done during the diagnostic session because of its duration. The present study aimed to verify the efficacy of a different forced position, shortened forced position (SFP), with respect to the original FPP. SFP treatment would allow patients to more easily bear the forced position and physicians to control the outcome almost immediately, possibly enabling them to dismiss patients without vertigo. After 1 h of lying on the side where vertigo and nystagmus are the less intense, 38 out of 53 (71.7%) patients treated with SFP were either healed or improved. Although the outcomes are not as satisfying as those of the original FPP, SFP should be considered as a therapeutic prospect, especially by those physicians who work in collaboration with emergency departments or otherwise encounter acute patients to cure them of vertigo as soon as possible.

Characteristics and utility of combined duplex color-coded ultrasonography in the cervical rotational position with head MRI and MRA in the differential diagnosis of apogeotropic direction-changing positional nystagmus

ObjectiveTo determine whether cervical ultrasonography, magnetic resonance imaging (MRI), and magnetic resonance angiography (MRA) are useful in the differential diagnosis of etiology and understanding the pathophysiology in cases of apogeotropic direction-changing positional nystagmus (DCPN). MethodsThirty patients with apogeotropic DCPN were classified into 11 cases of central disease, seven cases of mixed central and peripheral disease, and 12 cases of peripheral disease by differential diagnosis based on various balance function, neuro-otological, and imaging tests.Cervical ultrasonography using the cervical rotation method and MRI and MRA of the head and neck were performed in most patients with apogeotropic DCPN. We reviewed the presence of abnormal imaging findings according to the disease etiology. ResultsOf the 30 patients with apogeotropic DCPN, 23 showed vascular abnormalities or central lesions on imaging. Vascular lesions were found in six of the 12 patients with peripheral disease. Cervical ultrasonography with cervical rotation detected blood flow disturbance in the vertebral artery in eight patients in whom the disturbance could not be detected by MRI or MRA of the head and neck. DiscussionWe hypothesize that the causative disease of apogeotropic DCPN may be strongly associated with circulatory insufficiency of the vertebrobasilar and carotid arteries, and that impaired blood flow in these vessels may affect peripheral vestibular and central function. In patients with apogeotropic DCPN, examinations of vestibular function, central nervous system symptoms, and brain hemodynamics are valuable for differential diagnosis.

Assessing Agreement Between Upright and Supine Head Roll Tests for Horizontal Semicircular Canal Benign Paroxysmal Positional Vertigo

Background and Objectives The newly introduced upright head roll test (UHRT), which exploits head rotations in the roll plane with the patient in the upright sitting position, is a diagnostic maneuver for horizontal canal-benign paroxysmal positional vertigo (HC-BPPV). This study is designed to determine whether UHRT, compared to supine head roll test (SHRT), can more accurately diagnose HC-BPPV and determine the subtype of HC-BPPV.Subjects and Method A total of 455 video nystagmus tests performed between April 2019 to June 2021 were retrospectively reviewed, and 63 patients with direction-changing positional nystagmus at UHRT or SHRT were enrolled in this study. UHRT result was classified as negative (if no nystagmus was observed), positive incomplete (if nystagmus was detected in one side), and positive complete (if nystagmus was evoked in both side). The frequency of nystagmus is also included in our assessment. In addition, the results of 4 patients with bow and lean test (BLT) records on videonystagmography were also analysed.Results The concordance rate between UHRT and SHRT was 97.8%, and the positive concordance rate was 91.38%. UHRT and SHRT provided identical subtype diagnosis in 98.1% (52 of 53 cases). In one case, UHRT and SHRT showed opposite results. Evaluating the affected side with bow and lean records, the SHRT, UHRT and BLT showed consistent results. The mean frequency of nystagmus was faster in SHRT than in UHRT.Conclusion UHRT showed equivalent results to SHRT in distinguishing subtype of HC-BPPV. UHRT is a useful method in diagnosing HC-BPPV simply in a sitting position.

“Sitting-up vertigo as an expression of posterior semicircular canal heavy cupula and posterior semicircular canal short arm canalolithiasis”

BackgroundVestibular symptoms on sitting-up are frequent on patients seen by vestibular specialists. Recently, a benign paroxysmal positional vertigo (BPPV) variant which elicits vestibular symptoms with oculomotor evidence of posterior semicircular canal (P-SCC) cupula stimulation on sitting-up was described and named sitting-up vertigo BPPV. A periampullar restricted P-SCC canalolithiasis was proposed as a causal mechanism. ObjectiveTo describe new mechanisms of action for the sitting-up vertigo BPPV variant. MethodsEighteen patients with sitting-up vertigo BPPV were examined with a pre-established set of positional maneuvers and follow-up until they resolved their symptoms and clinical findings. ResultsAll patients showed up-beating torsional nystagmus (UBTN) and vestibular symptoms on coming up from either Dix-Hallpike (DHM) or straight head-hanging maneuver. Sixteen out of 18 patients presented a sustained UBTN with an ipsitorsional component to the tested side on half-Hallpike maneuver (HH). A slower persistent contratorsional down-beating nystagmus was found in eleven out 18 patients tested on nose down position (ND). ConclusionsPersistent direction changing positional nystagmus on HH and ND positions indicative of P-SCC heavy cupula was found in 11 patients. A sustained UBTN on HH with the absence of findings on ND, which is suggestive of the presence of P-SCC short arm canalolithiasis, was found on 5 patients. All patients were treated with canalith repositioning maneuvers without success, but they resolved their findings by means of Brandt-Daroff exercises. We propose P-SCC heavy cupula and P-SCC short arm canalolithiasis as two new putative mechanisms for the sitting-up vertigo BPPV variant.

Analysis of persistent geotropic and apogeotropic positional nystagmus of the lateral canal benign paroxysmal positional vertigo

ObjectiveThis study aims to analyze the clinical characteristics of persistent geotropic and apogeotropic positional nystagmus of LC-BPPV in view of light and heavy cupula discussion. Material and methodThe study group includes 184 patients with LC BPPV (98 apogeotropic, 86 geotropic type) who have been examined between 2009 and 2020. Ninety-nine females and 85 males, aged between 16 and 92 years were included (Ageotropic 49.32 ± 14.12, geotropic 44.49 ± 13.90 years). Average slow phase velocity (SPV) of positional nystagmus was documented and those with persistent direction-changing positional nystagmus lasting more than a minute were grouped separately. Age, gender difference, side of involvement, and recurrence pattern were particularly reviewed. Chi-square and One way ANOVA tests were used to compare the difference between groups. Statistical significance was set at P < 0.05. ResultsThirty-seven patients with apogeotropic nystagmus (30.7%; 37/98) and 18 patients with geotropic nystagmus (20.9%; 18/86) had persistent nystagmus (p ˂0.05). Comparison of slow phase velocity (SPV) of persistent and non-persistent geotropic and apogeotropic positional nystagmus of the affected side was significant (p ˂0.05). Comparison of average age, male to female ratio, side of involvement, and the recurrence rate in patients with persistent and non-persistent geotropic and apogeotropic type positional nystagmus groups were not significant (p = 0.177, p = 0.521, p = 0.891, p = 0.702). ConclusionPersistent geotropic and apogeotropic positional nystagmus is mostly correlated with the size, amount, and position of otoconial debris. It is difficult to justify the light cupula as a new geotropic variant of cupular pathology. Patients with persistent positional nystagmus present similar therapeutic outcomes and recurrence rates.

Clinical Manifestations of Benign Paroxysmal Positional Vertigo of the Horizontal Semicircular Canal: Pathophysiology of Atypical Manifestations

The presence of a direction changing positional nystagmus (DCPN) in a patient with vertigo is the characteristic sign to diagnose a benign paroxysmal positional vertigo of the horizontal semicircular canal (HSC-BPPV). If a persistent DCPN is observed when positional tests are performed, a light or heavy cupula phenomenon must be suspected. In order to differentiate between these clinical phenomena, a null plane test should be considered for diagnosis. On the other hand, when a paralytic or irritative fixed direction nystagmus is found, then a complete or incomplete jamming within the HSC may be involved. In this particular situation a head shaking nystagmus test may be clarifying. When persitent DCPN or paralytic-irritative nystagmus are found in positional testing, ENT clinicians must keep alert to search for atypical clinical forms of HSC-BPPV.

Nystagmus in adult patients with acute otitis media or otitis media with effusion without dizziness.

The present study aimed to investigate the incidence and patterns of nystagmus in adult patients with acute otitis media (AOM) or otitis media with effusion (OME) without dizziness or vertigo, and discuss possible mechanisms. From February 2018 to November 2018, 34 consecutive patients with AOM or OME without dizziness were included. Nystagmus was examined with video Frenzel glasses. Of 34 adult AOM or OME patients without dizziness, nystagmus was observed in 28 patients (82%). In unilateral AOM or OME (n = 30), the most commonly observed nystagmus pattern was irritative-type direction-fixed nystagmus (n = 13), followed by paretic-type direction-fixed nystagmus (n = 8), and direction-changing positional nystagmus (n = 4). In bilateral AOM or OME (n = 4), direction-fixed nystagmus and direction-changing positional nystagmus were observed in two and one patients, respectively. Nystagmus was observed in as many as 82% of adult AOM or OME patients even though they did not complain of dizziness, and the pattern of nystagmus was either direction-fixed or direction-changing. Direct effect of inflammatory mediators penetrated from the middle ear and biochemical alteration in the inner ear fluids due to blood-perilymph barrier dysfunction may result in the presence of nystagmus in AOM or OME patients without dizziness.

Clinical Implications of Horizontal Beating Nystagmus Induced by Dix-Hallpike Test in the Diagnosis of Horizontal Canal Benign Paroxysmal Positional Vertigo.

The purpose of this study was to identify the diverse patterns of nystagmus during the Dix-Hallpike test (DHT) and analyze their clinical significance in horizontal canal benign paroxysmal positional vertigo (HC-BPPV). Retrospective medical records review. Two hundred ninety-five patients diagnosed with HC-BPPV. Various nystagmus patterns identified during the DHT in patients with HC-BPPV were analyzed. The correlation between the affected side of HC-BPPV and the direction of the horizontal beating nystagmus (HBN) during the DHT was also analyzed. The nystagmus pattern during the DHT in 128 patients with geotropic HC-BPPV demonstrated, direction-changing positional nystagmus on both sides in 48 (37.5%) patients, HBN toward one side in 25 (19.6%) patients, and no nystagmus in 55 (42.9%) patients. In 144 patients with apogeotropic HC-BPPV, 54 (37.5%) patients presented with direction-changing positional nystagmus on both sides, 27 (18.8%) patients presented with HBN toward one side, and 63 (43.7%) patients did not show nystagmus during the DHT. The direction of HBN provoked by the DHT was significantly correlated with the affected side in each subtype of HC-BPPV (geotropic type, p = 0.049; apogeotropic type, p = 0.040; respectively). More than half of the patients with HC-BPPV (56.6%) showed HBN during the DHT. When HBN was present during the DHT, it may provide a clue for determining the subtype and affected side in diagnosis of HC-BPPV before performing the supine roll test.

Clinical Characteristics of Patients with Persistent Apogeotropic and Persistent Geotropic Direction-Changing Positional Nystagmus.

Background and PurposeThis study aimed to determine the clinical features, diagnosis, and treatment of patients with persistent geotropic (pG) and persistent apogeotropic (pAG) direction-changing positional nystagmus (DCPN).MethodsThis retrospective study included 30 patients with pG-DCPN and 44 patients with pAG-DCPN. All patients underwent neurological and neurotological examinations, including an evaluation of gaze-evoked nystagmus, eye-movement tests, and assessments of limb ataxia and balance, as well as magnetic resonance imaging to exclude central causes. The characteristics of positional nystagmus were detected using the supine roll test (SRT) and bow-and-lean test (BLT). The null point (NP) at which the nystagmus disappeared was determined. All patients were treated with the barbecue maneuver, and treatment efficacy was evaluated immediately, 1 week, and 1 month after treatment.ResultsThe history of diseases associated with atherosclerosis, peripheral vestibular disorders, otological disease, and migraine differed significantly between patients with pG-DCPN and pAG-DCPN. The affected sides of persistent horizontal DCPN can be determined using the SRT and the BLT, while determining the second NP and vestibular function as well as performing an audiological evaluation can be used to assist in identifying the affected side. The efficacy rates immediately and 1 week after treatment with the barbecue maneuver were higher in patients with pAG-DCPN than in patients with pG-DCPN.ConclusionspAG-DCPN was more compatible with the characteristics of cupulolithiasis, and pG-DCPN was more likely to be associated with a light cupula rather than canalolithiasis. pAG-DCPN was more likely to be accompanied by a disease associated with atherosclerosis, while pG-DCPN was often accompanied by autoimmune-related diseases and a history of migraine. The associations between pAG-DCPN, pG-DCPN, and the above-mentioned diseases need to be clarified further. The canalith-repositioning maneuver was effective in patients with pAG-DCPN and ineffective in patients with pG-DCPN, but most cases of pG-DCPN are self-limiting.

A Case of Persistent Direction-Changing Positional Nystagmus with Sudden Sensorineural Hearing Loss

A Case of Persistent Direction-Changing Positional Nystagmus with Sudden Sensorineural Hearing Loss

Spontaneous Direction-Changing or Reversing Positional Nystagmus without Changing Head Position during Head-Roll/Head-Hanging Maneuvers: Biphasic Positional Nystagmus

Background and ObjectivesConflicting mechanisms have been reported about spontaneous reversal of positional nystagmus during head-roll maneuver in patients with benign paroxysmal positional vertigo (BPPV). The objective of this study is to review the reports about the characteristics and possible mechanisms of reversing positional nystagmus and to present seven new cases.Subjects and MethodsSeven cases (5 males, 2 females; 4 left-sided, 3 right-sided) were recruited among 732 patients with BPPV seen outpatient clinic between 2009 and 2019. Diagnosis of lateral canal canalolithiasis was confirmed when transient geotropic nystagmus was documented during head-roll test. Reversing positional nystagmus was analyzed in each case and clinical characteristics of the patients were documented.ResultsThe age of patients was ranging between 30 to 64 years (46.44±10.91). Duration of symptoms was short (21.34±19.74). Six of them had a story of head trauma. Initial latency was short. First, intense geotropic nystagmus was observed following provocative head-roll position on the affected side. There was short “silent phase”. Then, a longer second-phase of reversed nystagmus was noted. Total duration of nystagmus was 78.40±6.82 seconds. Maximal slow phase velocity was 24.05±6.34 deg/sec. All patients were cured with barbeque maneuver.ConclusionsIpsilateral reversing positional nystagmus during head-roll maneuver is due to lateral canal canalolithiasis. Mechanism is likely to be due to endolymphatic double flow. Bilateral cases may be due to simultaneous co-existence of canalolithiasis and cupulolithiasis. Longer recording of nystagmus is recommended not to miss the cases with spontaneous direction-changing positional nystagmus.

Positional Audiometry in Patients with Light Cupula: A Preliminary Study

Objectives: Light cupula is characterized by persistent geotropic direction-changing positional nystagmus in a supine head-roll test. The purpose of this study is to investigate if hearing level is influenced by the change of head position in light cupula under the assumption that relative density difference similarly occurs between the tectorial membrane and endolymph. Methods: Twelve patients with unilateral light cupula who underwent positional audiometry were included in this study. Pure tone thresholds were compared among three head positions. Results: Hearing threshold in pure tone audiometry (PTA) of the affected ear was not different from that of the healthy ear. PTA thresholds of the affected side were not significantly different in three head positions; upright seating, cochlear apex-up, and cochlear apex-down positions. Conclusions: Although positional change of nystagmus direction is the most significant clinical feature of light cupula, positional change of hearing level was not observed in those patients. The lack of positional influence on hearing may be explained as follows: (1) the heavier endolymph phenomenon occurs only in the vestibular end organ without involving the cochlea; (2) the light cupula phenomenon is more likely to occur due to light debris mechanism rather than heavier endolymph or lighter cupula mechanism; and (3) the effects of light cupula could be modified by outer hair cells, which work for tuning in the cochlea, even though light tectorial membrane or heavy endolymph occurs. Keywords: Light cupula; Positional audiometry; Vertigo; Nystagmus; Hearing loss 중심 단어: 가벼운팽대부마루, ì²´ìœ„ì„±ì²­ë ¥ê²€ì‚¬, 현훈, 안진, 난청

Nystagmus in patients with lateral semicircular canal dysplasia

Background Dizziness is not a common symptom in the lateral semicircular canal (LSCC) dysplasia, and nystagmus findings has been rarely described in LSCC dysplasia. Objective To investigate the characteristics of spontaneous and positional nystagmus in patients with LSCC dysplasia. Methods Patterns of spontaneous and positional nystagmus of twelve patients with LSCC dysplasia, who visited our clinic with a chief complaint of dizziness, were investigated. Results LSCC dysplasia was observed unilaterally in 4, and bilaterally in 8 patients. Non-rotatory dizziness with various onset times was the most common description of dizziness, and unilateral caloric weakness was observed in 82% of patients. Direction-fixed nystagmus, in which the direction of spontaneous nystagmus was same with that of positional nystagmus, was observed in 9 patients, and direction-changing positional nystagmus, in which the direction of nystagmus was changed from that of spontaneous nystagmus by positioning maneuvers, was observed in 3 patients, of whom down-beating or direction-changing spontaneous nystagmus was observed in one patient each. Conclusion While direction-fixed horizontal nystagmus is the most commonly observed type of nystagmus in LSCC dysplasia, atypical spontaneous nystagmus, such as down-beating nystagmus or direction-changing spontaneous nystagmus, may be observed in patients with bilateral LSCC dysplasia.

Nystagmus in Ramsay Hunt syndrome with or without dizziness.

The presence of dizziness has been reported as a negative prognostic factor for recovery of facial palsy in Ramsay Hunt syndrome (RHS). The aim of this study was to investigate the incidence and patterns of nystagmus in RHS patients without dizziness, and discuss possible mechanisms. We also compared the severity and prognosis of facial palsy between RHS patients with and without dizziness. From January 2014 to January 2019, 36 patients diagnosed with RHS (27 with dizziness and 9 without dizziness) were included. Patterns of nystagmus were examined and categorized using video-nystagmography. House-Brackmann(HB) grade of facial palsy was compared between RHS patients with and without dizziness. Not only RHS patients with dizziness exhibited nystagmus in most cases (96%, 26 of 27) but also as many as 67% (6 of 9) of RHS patients without dizziness exhibited nystagmus, though the intensity was remarkably weak. In both groups of RHS with and without dizziness, direction-fixed nystagmus and direction-changing positional nystagmus were observed. Initial HB grade and recovery of facial palsy after treatment were not significantly different between RHS with and without dizziness. Various patterns of nystagmus including direction-fixed and positional direction-changing nystagmus were observed in RHS patients, and inflammation of the vestibular nerve and inner ear end organs may be responsible for the production of nystagmus in these patients. The results support that the evaluation of vestibular function may be necessary even in RHS patients who do not complain of dizziness or vertigo.