Benign Paroxysmal Positional Nystagmus Research Articles

Semicircular canal biomechanics in health and disease.

The semicircular canals are responsible for sensing angular head motion in three-dimensional space and for providing neural inputs to the central nervous system (CNS) essential for agile mobility, stable vision, and autonomic control of the cardiovascular and other gravity-sensitive systems. Sensation relies on fluid mechanics within the labyrinth to selectively convert angular head acceleration into sensory hair bundle displacements in each of three inner ear sensory organs. Canal afferent neurons encode the direction and time course of head movements over a broad range of movement frequencies and amplitudes. Disorders altering canal mechanics result in pathological inputs to the CNS, often leading to debilitating symptoms. Vestibular disorders and conditions with mechanical substrates include benign paroxysmal positional nystagmus, direction-changing positional nystagmus, alcohol positional nystagmus, caloric nystagmus, Tullio phenomena, and others. Here, the mechanics of angular motion transduction and how it contributes to neural encoding by the semicircular canals is reviewed in both health and disease.

Central paroxysmal positional nystagmus: Characteristics and possible mechanisms.

The diagnosis of central paroxysmal positional nystagmus (CPPN) is challenging, and the mechanisms require further elucidation. This study aimed to determine the characteristics and mechanisms of CPPN. Seventeen patients with CPPN were subjected to analyses of their clinical findings, MRI lesions, and oculographic data on spontaneous and positional nystagmus. The direction of CPPN was mostly aligned with that of the head motion during the positioning, and 3 types of CPPN were identified: downbeat nystagmus on straight-head hanging, upbeat nystagmus on uprighting, and apogeotropic nystagmus during supine head roll test. The direction of CPPN was aligned with the vector sum of the rotational axes of the semicircular canals that were normally inhibited during the positioning. The intensity of evoked nystagmus was at its peak initially and then decreased exponentially over time. The time constants (TC) of the vertical CPPN ranged from 3 to 8 seconds, which corresponds to the TC of the vertical rotational vestibulo-ocular reflex. Sixteen patients (94.1%) showed more than one type of CPPN. Furthermore, persistent downbeat or apogeotropic positional nystagmus was associated in 11 patients (64.7%). Most patients with CPPN from a circumscribed brain lesion showed an involvement of the cerebellar nodulus or uvula. CPPN may be ascribed to enhanced responses of the vestibular afferents due to lesions involving the nodulus and uvula. CPPN could be differentiated from benign paroxysmal positional nystagmus by positional nystagmus induced in multiple planes, temporal patterns of nystagmus intensity, and associated neurologic findings suggestive of central pathologies.

Pseudo-anterior canalolithiasis

Conclusion: Because nystagmus induced by ampullopetal inhibition of the posterior semicircular canal (PSCC) rotates around the axis perpendicular to the plane of the anterior semicircular canal (ASCC) of the other side, when free-floating debris is initially located at the distal portion of the PSCC, a patient showing positional nystagmus appears to have the ASCC type of benign paroxysmal positional nystagmus. We name this ‘pseudo-anterior canalolithiasis'. Objective: We report on pseudo-anterior canalolithiasis originating in the PSCC and discuss the differential findings between pseudo-anterior and true anterior canalolithiasis by means of three-dimensional (3D) analysis of the positional nystagmus. Methods: We performed 3D analysis of the positional nystagmus in a patient with true anterior canalolithiasis and in another patient with pseudo-anterior canalolithiasis. Results: In the patient with true anterior canalolithiasis, the direction of positional nystagmus during reverse Epley maneuver was constant and its axis was perpendicular to the plane of the right ASCC three-dimensionally. In contrast, in the patient with pseudo-anterior canalolithiasis, the first positional nystagmus of which the axis was perpendicular to the plane of the left ASCC became a second positional nystagmus of which the axis was perpendicular to the plane of the right PSCC during the reverse Epley maneuver.

Analysis of benign paroxysmal positional nystagmus in children

IntroductionBenign paroxysmal positional vertigo (BPPV) is the most common vestibular disorder. However, BPPV in children has been studied less extensively than in the adult population. This is because the observation of benign paroxysmal positional nystagmus (BPPN) in children is technically very difficult and BPPV is rare in children. In this study, we present the only two cases of BPPV in children in which we successfully recorded and analyzed the BPPN. MethodsOne case was an 11-year-old boy and the other was a 3-year-old girl. We analyzed their BPPN three-dimensionally. ResultsApogeotropic positional nystagmus was observed in the first case. We analyzed it to verify the presence of cupulolithiasis in the horizontal semicircular canal (HSCC). Geotropic positional nystagmus was observed in the second case, and the analyzed data indicated the presence of canalolithiasis in HSCC. Over the last decade, we have examined 3341 patients complaining of vertigo or dizziness. Among them, there were 63 children with the same complaint, so that the proportion of cases of BPPV in children was only 3% (2/63). DiscussionAmong patients complaining of vertigo or dizziness, children with BPPV are rare (3%). However, we have recorded their BPPN to confirm that BPPV does occur in children and that their characteristics of positional nystagmus are generally identical to those in adults. We emphasize that this is the first report of a child as young as 3 years old being diagnosed with BPPV.

Particle Repositioning Maneuver Versus Brandt-Daroff Exercise for Treatment of Unilateral Idiopathic BPPV of the Posterior Semicircular Canal

To compare the outcome and probability of recurrence in a series of patients with unilateral idiopathic benign paroxysmal positional vertigo of the posterior canal (PC-BPPV) that were randomly treated by Brandt-Daroff exercise (B-D exercise) or by particle repositioning maneuver (PRM). Randomized prospective clinical trial. Tertiary referral center. Patients were included in this study if they complained of vertigo and had been diagnosed as having unilateral idiopathic PC-BPPV for at least 1 week before Dix-Hallpike maneuver (DHM), remained for 30 days in the randomly assigned treatment, and had at least 48 months' follow-up. Forty-one patients were treated with a single PRM and 40 patients by B-D exercise. Resolution of benign paroxysmal positional nystagmus on the DHM. The probability of recurrence was also studied. At Day 7, DHM was negative in 80.5% of the PRM-treated patients and in 25% of those treated by B-D exercise (p < 0.001). At Month 1, the differences between both treatment groups remained statistically significant (92.7% in PRM versus 42.5% in the B-D exercise had a negative DHM; p < 0.001). The variable that influenced that DHM became negative was the PRM (RR = 4.8; 95% confidence interval, 2.5-9.2; p < 0.001). The number of recurrences in PRM and B-D exercise were 0.56 ± 0.8 and 0.48 ± 0.8, respectively (p = 0.48). The recurrence rate at 48 months was 35.5% (15/41) in B-D exercise and 36.6% (9/31) in the PRM group (p = 0.62). Although the time interval until the first recurrence was similar (p = 0.44), patients included in the PRM group showed a significantly longer time interval between the first and second recurrence (p = 0.04). PRM is more effective treatment and as safe as B-D exercise in the short term for unilateral and idiopathic PC-BPPV, and although it does not reduce the probability of recurrence in the 4-year follow-up period compared with B-D exercise, it may delay the second recurrence's onset in those patients who had already experienced a single recurrence. Our study supports the use of PRM as the treatment of choice in unilateral and idiopathic PC-BPPV, although exercise may be also considered as an alternative treatment in selected cases.

Effectiveness of Particle Repositioning Maneuvers in the Treatment of Benign Paroxysmal Positional Vertigo: A Systematic Review

Benign paroxysmal positional vertigo (BPPV) is the most common cause of vertigo. The purpose of this systematic review was to determine whether patients diagnosed with posterior canal (PC) BPPV, based on positional testing, and treated with a particle repositioning maneuver will show the resolution of benign paroxysmal positional nystagmus (BPPN) on the Dix-Hallpike Test performed 24 hours or more after treatment. Data were obtained from an electronic search of the MEDLINE, EMBASE, and CINAHL databases from 1966 through September 2009. The study topics were randomized controlled trials (RCTs), quasi-RCTs, the diagnosis of PC BPPV, treatment with the particle repositioning maneuver, and outcome measured with a positional test 24 hours or more after treatment. Data extracted were study descriptors and the information used to code for effect size. In 2 double-blind RCTs, the odds in favor of the resolution of BPPN were 22 times (95% confidence interval=3.41-141.73) and 37 times (95% confidence interval=8.75-159.22) higher in people receiving the canalith repositioning procedure (CRP) than in people receiving a sham treatment. This finding was supported by the results reported in 8 nonmasked quasi-RCTs. Studies with limited methodological quality suggested that a liberatory maneuver (LM) was more effective than a control intervention; there was no significant difference in the effectiveness of the LM and the effectiveness of the CRP; the self-administered CRP was more effective than the self-administered LM; and the CRP administered together with the self-administered CRP was more effective than the CRP administered alone. The Brandt-Daroff exercises were the least effective self-administered treatments. The limitations included the methodological quality of the studies, the lack of quality-of-life measures, and confounding factors in reporting vertigo. Randomized controlled trials provided strong evidence that the CRP resolves PC BPPN, and quasi-RCTs suggested that the CRP or the LM performed by a clinician or with proper instruction at home by the patient resolves PC BPPN. There were no data on the effects of the maneuvers on outcomes relevant to patients.

Differential diagnosis of true and pseudo-bilateral benign positional nystagmus

Conclusions. Two patients showing two rotational axes of their positional nystagmus had canalolithiasis in bilateral posterior semicircular canals (PSCCs), leading to the diagnosis of true bilateral benign paroxysmal positional nystagmus (P-BPPN). Another 18 patients had a single rotation axis of their positional nystagmus with short time constant (TC) on one side and long TC on the other. Since canalolithiasis in the uppermost PSCC may be transient cupulolithiasis, evoking positional nystagmus with long TC, the diagnosis of the latter patients should be pseudo-bilateral P-BPPN. Objective. To differentiate the true bilateral posterior canal type of P-BPPN from pseudo-bilateral P-BPPN. Patients and methods. The rotational axis and TC of positional nystagmus were three-dimensionally analyzed in 20 patients showing geotropic torsional nystagmus on the left and right Dix-Hallpike (D-H) maneuvers. Results. Two patients showed two rotational axes of their positional nystagmus, which were perpendicular to the plane of the PSCCs. There were no differences in TCs of their positional nystagmus between bilateral D-Hs. Another 18 patients showed a single rotational axis of their positional nystagmus, which was perpendicular to the plane of either the left or right PSCC. TCs of their positional nystagmus were short on one side and long on the other.

Giant cell arteritis: a new association with benign paroxysmal positional vertigo.

To assess the incidence and characteristics of both benign paroxysmal positional vertigo (BPPV) and positional nystagmus in a series of patients with giant cell arteritis (GCA). Patients diagnosed with GCA between June 1999 and May 2001 at the single hospital for a defined population were examined prospectively. Patients included in this study fulfilled the 1990 American College of Rheumatology classification criteria for GCA. Otologic and oculographic studies were performed. Type, frequency, and outcome of positional oculographic findings was assessed. Patients were required to have been examined within 1 week after the onset of corticosteroid therapy. Data found in GCA patients were compared with those observed in an age, sex, and ethnically matched control population. Further studies in patients and controls were performed 3 and 6 months later. Forty-four patients and 44 matched controls were included in this study. Nine (20.5%) GCA patients fulfilled diagnostic criteria of BPPV compared with only 1 (2.3%) of the controls (P =.007). In seven of these nine GCA patients, BPPV was related to the posterior and two to the horizontal semicircular canals, respectively. Horizontal nystagmus was found in seven GCA patients who developed nystagmus in the head hanging position test compared with none in the controls (P =.006). The present study shows a higher frequency of BPPV in GCA than in matched controls. Because most clinical manifestations in GCA are caused by ischemic complications, our results suggest an ischemic etiology as responsible for BPPV in these elderly patients. According to these results, GCA may constitute a new association with BPPV.

Benign paroxysmal positional nystagmus in hospitalized subjects receiving ototoxic medications.

To investigate the occurrence of benign paroxysmal positional nystagmus in subjects undergoing treatment with potentially ototoxic medications. Prospective and retrospective record reviews. Tertiary referral neurotology clinic; clinical research and technology center. Ninety-nine hospitalized subjects undergoing treatment of infectious disease or carcinoma with potentially ototoxic medications. Records review, tests of vestibular function. Results of Hallpike positional tests for benign paroxysmal positional nystagmus (electro-oculography). Forty-one (41%) of 99 subjects were female and 58 (59%) were male. Age range was 15 to 73 years (mean, 47 years). Forty-nine (50%) of 99 subjects had an unequivocally positive Hallpike test for benign paroxysmal positional nystagmus in one or both ears. The occurrence of benign paroxysmal positional nystagmus in the Hallpike-positive population was distributed equally across age decades. Of the 49 subjects with benign paroxysmal positional nystagmus, 22 (44%) were female and 27 (56%) were male. Benign paroxysmal positional nystagmus is the most common cause of vertigo in the general population, including subjects receiving ototoxic drugs. Complaints of vertigo in subjects receiving ototoxic drugs therefore may or may not indicate onset of ototoxicity. Occurrence of benign paroxysmal positional nystagmus in subjects receiving ototoxic drugs was independent of gender or age. The high occurrence rate of benign paroxysmal positional nystagmus in subjects receiving potentially ototoxic medications is consistent with the observation that benign paroxysmal positional nystagmus occurs in combination with many pathologic conditions. Benign paroxysmal positional nystagmus presenting in subjects receiving ototoxic drugs may complicate the clinical identification of ototoxicity and obfuscate clinical decision-making processes.

Evaluation of vestibular functions in children with vertigo attacks

Aim: To examine vestibular system functions in children with episodic vertigo attacks. Methods: Thirty four children (20 males) aged 4–18 years with paroxysmal dizziness and/or vertigo attacks were evaluated. A...

良性発作性頭位めまい症の回旋性眼振の垂直成分

Benign paroxysmal positional vertigo (BPPV), one of the most common diseases of peripheral vestibular origin, is characterized by transient vertigo accompanied by benign paroxysmal positional nystagmus (BPPN) provoked by turning over in bed, lying down or sitting up. BPPN with a torsional component, short latency and a crescendo-decrescendo mode, is provoked by positional testing and disappears within 30 sec. The direction of the torsional nystagmus, provoked by lying down, reverses by sitting up. The nystagmus may decrease by repeated provocations as an adaptation. Canalolithiasis of the posterior canal is widely accepted as a cause of BPPV, because BPPN is well predicted and BPPV is successfully treated by Epley's canalith repositioning procedure on the basis of this hypothesis. Canalolithiasis of both the horizontal and anterior canals has also been reported as BPPV-variants. In this study, BPPN recorded by an infrared CCD camera and video recorder, and the incidence and meaning of the vertical component of BPPN were investigated in 110 cases of BPPV with torsional BPPN. Out of all 110 cases, up beating vertical component appeared in 39 (35.5%), down beating in 24 (21.8%) and no vertical component in 47 cases (42.7%), when torsional BPPN was provoked by lying down. Horizontal nystagmus of the direction changing type was also observed in 4 cases. According to the canalolithiasis hypothesis, upward and downward vertical components triggered by lying down should occur in the posterior and anterior canal types, respectively. Pure torsional positional nystagmus provoked by positioning was assumed to occur in the crus communis type, in which free-floating endolymph particles remain in the crus communis of the labyrinth.

Robert Bárány and the controversy surrounding his discovery of the caloric reaction.

It was not until the latter half of the 19th century that the vestibular part of the inner ear was recognized to have a function separate from hearing. Robert Bárány was one of the first clinicians to assess vestibular function systematically in patients. He developed standard caloric, rotational, and pointing tests and was the first to describe benign paroxysmal positional nystagmus. Bárány began his career working in the otology clinic of Adam Politzer at the University of Vienna. He received the Nobel Prize in Medicine in 1916 for his work on the mechanism of the caloric reaction. However, in the aftermath of the First World War and the controversy surrounding his selection for the Nobel Prize, Bárány left Vienna for Uppsala, Sweden, where he spent the last 20 years of his life in relative isolation.

Orientational evaluation of otolith function by eye counter-rolling in patients with various kinds of vertigo

Measurement of ocular counterrolling (OCR) is well known as a simple method to evaluate the peripheral vestibular organ, especially the otolith organ. But it has rarely been used because of the difficulty in differentiating between pathologically reduced OCR and the wide physiological variation of this parameter. In this study, the OCR of 55 patients with unclarified vertigo (n = 20), vestibular neuronitis (n = 15), Menière's disease (n = 10), and benign paroxysmal positional nystagmus (n = 10) were evaluated and compared to a control group (n = 30) with the intention of diagnosing peripheral vestibular dysfunction and establishing a differential diagnosis. The test sequence was carried out with Vesta goggles by Panares and included head tilts of 5 degrees, 15 degrees, and 30 degrees to the left and right. The results show a significantly reduced OCR in patients suffering from peripheral vestibular disorders when compared to the control group. There is no specific finding for a specific type of vestibular lesion, but otolith function is affected in several disorders as measured by ocular counterrolling.

頭部外傷後の発作性頭位めまい症の２症例 方向交代性頭位眼振の検討

In 1962, Schuknecht reported that cupulolithiasis in the posterior semicircular canal caused by the otoconia detached from the otolithic membrane in the utricular macula was a possible cause of positional vertigo of the benign paroxysmal type (BPPV). In 1996, we reported that basophilic deposits adhered to the cupula in not only the posterior semicircular canals but also in the lateral and anterior semicircular canals. It is very interesting to evaluate the kinds of nystagmus caused by the cupulolithiasis and canalolithiasis in the lateral and anterior semicircular canals.In this study, the origin of direction changing positional nystagmus in the upper ear found in cases of benign paroxysmal positional nystagmus (BPPN) after head trauma was investigated. The subjects included two paients with direction changing positional nystagmus to the upper ear with BPPN after head trauma treated at the Neuro-otological clinic, Kitasato University Hospital between 1985 and 1996.It was suggested that the origin of this type of nystagmus as well as the various other types of nystagmus observed during their respective clinical courses was cupulolithiasis or canalolithiasis in the lateral semicircular canal and/or posterior semicircular canal.Although it was suggested that direction changing positional nystagmus from the upper or lower ear was caused by central vestibular disorder, especially that in the vermis, it was lil; ly that one case in this series was also caused by peripheral vestibular disorder.

Three-component analysis of benign paroxysmal positional nystagmus.

Three-component analysis of Benign Paroxysmal Positional Nystagmus (BPPN), focusing on the horizontal, vertical, and torsional, using a computerized eye movement analysis system, was carried out in 10 patients. Using a pendular rotation stimulus, we also measured three components of eye movement elicited from the vertical semicircular canals in normal subjects. We compared two components (vertical and torsional) of BPPN with that of eye movements elicited from the vertical semicircular canals. In BPPN, the torsional component of eye movements was larger than that of the vertical component. Conversely, the vertical component from the vertical semicircular canals was larger than that of the torsional component. From these results, by analysing the vestibulo-ocular reflex of the vertical semicircular canals, it is difficult to support the idea that the pathology of the BPPV is localized in the posterior semi-circular canal alone.

正弦波直線加速度刺激による耳石器機能検査法

正弦波直線加速度刺激による耳石器機能検査法

MAN IN MOTION

This is a review of selected aspects of the history of the vestibular system (J. E. Purkyne, E. Mach, A. Crum-Brown) and of our current understanding of vestibular malfunction in clinical vertigo syndromes. Evidence is presented for a preliminary classification of central vestibular brainstem syndromes according to the three major planes of action of the vestibulo-ocular reflex (VOR): (1) disorders of the VOR in the horizontal (yaw) plane (horizontal nystagmus, pseudo 'vestibular neuritis'); (2) disorders of the VOR in the sagittal (pitch) plane (downbeat nystagmus; upbeat nystagmus); (3) disorders of the VOR in the frontal (roll) plane (ocular tilt reaction; lateropulsion). The pathophysiology of peripheral vestibular disorders is discussed: a specific gravity differential between the cupula fluid and the endolymph (buoyancy mechanism) causes vertigo in benign paroxysmal positioning vertigo and positional alcohol nystagmus. Vestibular neuritis is probably a partial unilateral vestibular paralysis due to viral infection of the superior division of the nerve trunk. The common post-traumatic vertigo is explained by otolith dysfunction secondary to dislodged otoconia resulting in unequal loads on the macula beds and a tonus imbalance between the two otoliths.

卵円窓へのアルゴンレーザー照射による頭位眼振モデルの検討

Experimental positional nystagmus (EPN) similar to benign paroxysmal positional nystagmus (BPPN) was induced in 8 of 20 rabbits by argon laser irradiation to the footplate. The power of the argon beam used was 2.0 watts and irradiation time was 1 or 2 sec. EPN and BPPN showed the following similarities maintained (1) When the head was maintained in the affected ear down position and the head positioned from the sitting to the supine position nystagmus directed to the affected ear or vertical nystagmus corresponding to rotatory nystagmus in man were provoked. (2) Delayed onset for provocation of nystagmus. (3) Limited duration. (4) Fatigability. (5) The direction of nystagmus was reversed when the head returned to the initial position (in two rabbits). Histological examination of the temporal bones showed separation of otoconia from the otolithic membrane of the saccule and bleeding in the saccule in both conditions. No lesions in the utricle and semicircular canals were evident. It was assumed that ablation of otoconia of the saccule causes this experimental positional nystagmus.

A condition marked by benign paroxysmal positional nystagmus occurring during the course of Meniere's disease

A condition marked by benign paroxysmal positional nystagmus occurring during the course of Meniere's disease

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

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