Torsional Nystagmus Research Articles

The clinical characteristics of the evoked nystagmus in the non-affected side during Dix-Hallpike test in the unilateral posterior semicircular canal benign paroxysmal positional vertigo

Objective: To investigate the clinical characteristics of the evoked nystagmus in the non-affected side during Dix-Hallpike test(D-H test)in unilateral posterior semicircular canal benign paroxysmal positional vertigo(PC-BPPV). Method: Two hundred and thirty-six patients were diagnosed with unilateral PC-BPPV in the Tinnitus and Dizziness clinic.Among them,14 patients exhibited positive nystagmus when the non-affected side was stimulated by D-H test. The clinical data from this subgroup of patients were retrospectively analyzed. Result: The upbeat and torsional nystagmus of 14 patients were all evoked by D-H test in the affected side. 11 cases were right PC-BPPV and 3 cases were left PC-BPPV. Among these 14 patients, 5 patients exhibited the upbeat and torsional nystagmus during D-H test in the non-affected side, which was in the same direction as that evoked in the affected side. Among them, 4 cases were right PC-BPPV and 1 case was left PC-BPPV. However, the downbeat nystagmus of the remaining 9 patients were evoked by D-H test in the non-affected side, in which 7 cases were right PC-BPPV and 2 cases were left PC-BPPV.The nystagmus and vertigo of all patients completely disappeared after performing the Epley or Semont repositioning maneuvers on the affected side. Conclusion: The bilateral positive nystagmus of unilateral PC-BPPV can be evoked by D-H test. The form of nystagmus on the non-affected side is related with the initial position of otoconia in affected semicircular canal and the moving direction of otoconia during the positional test. It is effective to perform Epley or Semont repositioning maneuvers on the affected side. Meanwhile, both the effect of maneuvers and the type of nystagmus evoked by D-H test can verify which side is affected.

Incidence and Clinical Significance of Positional Downbeat Nystagmus in Posterior Canal Benign Paroxysmal Positional Vertigo.

Background and PurposeThe aim of this study was to determine the incidence and clinical significance of positional downbeat nystagmus (pDBN) after treatment of posterior canal (PC) benign paroxysmal positional vertigo (BPPV).MethodsWe recruited 77 patients with a diagnosis of PC BPPV, and assessed the presence of pDBN during follow-up positional tests after performing the Epley maneuver.ResultsAn immediate response to the Epley maneuver was exhibited by 57 of the 77 patients, with resolution of their positional torsional upbeat nystagmus (pT-UBN). Twenty-two (39%) of them exhibited pDBN during follow-up tests performed 1 hour later. The latency and duration of pDBN were 3.2±2.0 and 12.0±10.0 s (mean±SD), respectively. The maximum slowphase velocity of pDBN was 5.1±2.5 degrees, and ranged from 2.0 to 12.2 degrees. A torsional component was also observed in six patients. The patients with pDBN were much more likely to develop a typical form of PC BPPV again at a 1-week follow-up (5/22, 23%) compared to those without pDBN (1/31, 3%; p=0.036). pDBN disappeared in all patients within 6 months.ConclusionsOur study found transient pDBN in 40% of patients with PC BPPV after the immediate resolution of positional vertigo and pT-UBN. pDBN may be attributed to residual debris in the distal portion of the PC, which can move toward the ampulla producing an ampullopetal flow of endolymph during positioning.

Significance of the seated supine positioning nystagmus for the diagnosis of benign paroxysmal positional vertigo

Objective:To observe and assess the significance of seated supine positioning nystagmus (SSPN) in the diagnosis of benign paroxysmal positional vertigo(BPPV).Method:Two hundreds patients who were diagnosed BPPV were tested with the seated supine positioning test(SSPT) to observe SSPN,then were tested Supine roll test(SRT) and Dix-Hallpike test(DHT). According to the result of SRT and DHT,patients were divided into different groups. The positive rate and feature of SSPN in different types of BPPV was analyzed.Result:Among the 200 patients,116 cases(58.0%) of them showed SSPN. Among the 116 cases who were divided to the posterior semicircular canal BPPV(PSC-BPPV) group,72 cases of them showed SSPN. Horizontal semicircular canal BPPV(HSC-BPPV) group were 60 cases,44 cases showed SSPN. Anterior semicircular canal BPPV(ASC-BPPV) group were 4 cases and none of them showed SSPN. The direction of SSPN was a combination of torsional nystagmus with the upper pole of the eyes beating toward the affected side combined with vertical nystagmus beating upward (toward the forehead) typically in the PSC-BPPV group. Canalolithiasis of HSC were 41 cases,and 28 cases showed SSPN,and SSPN was contralesional in 22 cases(78.6%) and ipsilesional in 6 cases. Cupulolithiasis of HSC were 19 cases and 16 cases showed SSPN,and SSPN was ipsilesional in 16 cases.Conclusion:Significance of the seated supine positioning nystagmus in different types of BPPV is different.

Central Positional Nystagmus: A Systematic Literature Review.

To provide a systematic review of the clinical and radiological features of lesion-induced central positional nystagmus (CPN) and identify salient characteristics that differentiate central from peripheral positional nystagmus (PN). Systematic literature search according to the preferred reporting items for systematic reviews and meta-analysis. A total of 82 patients from 28 studies met the participants intervention, comparison, outcomes, and study designs criteria for inclusion. An atypical direction of nystagmus for the stimulated canal was reported in 97.5% patients during Dix-Hallpike (D-H) and 54.5% upon supine roll testing. Five types of CPNs were identified during positional testing: positional horizontal nystagmus (pHN) (36.8%), positional downbeating nystagmus (pDBN) (29.2%), positional torsional nystagmus (pTN) (2.1%), positional upbeating nystagmus (pUBN) (2.1%), and a combination of the four profiles (29.9%). CPN was paroxysmal (<60 s) in 85% patients on straight head hanging (SHH), 63.9% on D-H, and 37.5% on supine roll, and had a latency <3 s upon positioning in 94.7% patients in which it was reported. Concurrent vertigo was reportedly present in 63.4% patients and 48.8% demonstrated other neurological signs. Radiologically, in 74.4%, there was mention of cerebellar involvement, isolated brainstem involvement in 8.5%, and 14.6% involved the fourth ventricle. Currently, there is a lack of robust data on the clinical and radiological characteristics of CPN highlighting the need for better phenotyping of CPN to help differentiate this entity from peripheral causes of PN. With increased awareness of CPN, particularly in the acute setting, we may see a change in the estimated prevalence of CPN and improved clinical markers to promptly identify the frequently sinister underlying causes.

Juvenile nephronophthisis and dysthyroidism: a rare association.

Nephronophthisis, an autosomal recessive kidney disease, represents the most frequent genetic cause of end-stage kidney disease in the first three decades of life. A 27-year-old male was presented with gait imbalance, sever pruritus since 10days prior time of admission. In past medical history, he had bilateral cataract, torsional nystagmus, and bilateral optic nerve atrophy since 2years of age. He was also mentioned history of multinodular goiter with dysfunctional thyroid state since 2years before admission. At admission bilateral blindness, torsional nystagmus, asymmetric thyromegaly with nodularity was found in physical examination. Laboratory tests showed elevated urea and creatinine (200, 10.7mg/dl), hypomagnesemia (1.1mEq/l), decreased thyroid stimulating hormone (<0.004mIU/l). Ophthalmologist consultation confirmed retinitis pigmentosa. Renal sonography showed small-sized kidneys. Brain magnetic resonance imaging did not reveal molar tooth sign. Genetic testing performed and a large homozygous deletion at the NPHP1 gene locus was found. The patient was diagnosed with juvenile nephronophthisis and consideration of dysthyroidism as extrarenal manifestation of nephronophthisis is suggested in this case. Furthermore, loss of function mutation in SLC41A1 gene that leads to magnesium depletion must be noted in patients with suspected to nephronophthisis.

Observation of harmonic vestibulosomatic reactions in a patient with demyelinating lesion in the medulla oblongata region at the level of vestibular nuclei

The article is devoted to the problems of differential diagnosis of central and peripheral vestibular dysfunctions. Authors discuss the case of the so-called “pseudo-acute peripheral vestibulopathy” described in literature sources. The authors observe peripheral vestibular symptoms (horizontal–torsional contralesional spontaneous nystagmus and harmonic nature of axial lateropulsion during the study of equilibrium) in a patient with central vestibular disorder genesis – demyelinating disease in the region of the vestibular nuclei in the brain stem, confirmed by magnetic resonance imaging. The data of vestibular testing and the results of spontaneous nystagmus study by means of video-oculography are analyzed. The authors bring up the issue of the necessity of more careful exclusion of lesions in the area of the vestibular nuclei of the brain stem in patients with the signs of peripheral vestibular dysfunction, especially when they are accompanied by the central vestibular symptomatology.

Various Nystagmus Patterns and Their Clinical Significance in Benign Paroxysmal Positional Vertigo of Anterior Semicircular Canal

Objective The purpose of this study was to identify the diverse patterns of nystagmus and analyze their clinical significance in benign paroxysmal positional vertigo (BPPV) of the anterior semicircular canal. Methods Fifty-three patients diagnosed with anterior canal BPPV (AC-BPPV) were analyzed retrospectively. Patients were classified according to the presence or absence of the torsional component of the nystagmus and the direction of Dix-Hallpike test which induced the nystagmus. We compared the clinical characteristics and treatment outcomes among the different patient groups. Results There were 11 patients with unilateral down beat (DB) nystagmus, 11 patients with bilateral DB nystagmus, 14 patients with ipsilateral torsional down beat (TDB) nystagmus, 7 patients with contralateral TDB nystagmus, and 7 patients with bilateral TDB nystagmus. There were no differences between the unilateral and the bilateral DB groups in terms of the duration of nystagmus or vertigo and the number of treatment sessions. In addition, the ipsilateral TDB group showed no significant clinical difference compared to the contralateral or bilateral TDB group. Conclusion Various nystagmus patterns can be seen in AC-BPPV. There was no statistically significant difference in the clinical characteristics according to the different nystagmus patterns. This information may be helpful for clinicians in counseling and managing the patients with AC-BPPV. Keywords: Benign paroxysmal positional vertigo; Torsional nystagmus; Downbeat nystagmus; Anterior semicircular canal 중심 단어: 양성 돌발성 두위현훈, ì „ë°˜ê³ ë¦¬ê´€, íšŒì„ ì•ˆì§„, 하방안진

Vestibular and oculomotor influences on visual dependency.

The degree to which a person relies on visual stimuli for spatial orientation is termed visual dependency (VD). VD is considered a perceptual trait or cognitive style influenced by psychological factors and mediated by central reweighting of the sensory inputs involved in spatial orientation. VD is often measured with the rod-and-disk test, in which participants align a central rod to the subjective visual vertical (SVV) in the presence of a background that is either stationary or rotating around the line of sight-dynamic SVV. Although this task has been employed to assess VD in health and vestibular disease, what effect torsional nystagmic eye movements may have on individual performance is unknown. Using caloric ear irrigation, 3D video-oculography, and the rod-and-disk test, we show that caloric torsional nystagmus modulates measures of VD and demonstrate that increases in tilt after irrigation are positively correlated with changes in ocular torsional eye movements. When the direction of the slow phase of the torsional eye movement induced by the caloric is congruent with that induced by the rotating visual stimulus, there is a significant increase in tilt. When these two torsional components are in opposition, there is a decrease. These findings show that measures of VD can be influenced by oculomotor responses induced by caloric stimulation. The findings are of significance for clinical studies, as they indicate that VD, which often increases in vestibular disorders, is modulated not only by changes in cognitive style but also by eye movements, in particular nystagmus.

Classification, diagnostic criteria and management of benign paroxysmal positional vertigo.

Benign paroxysmal positional vertigo (BPPV) is the most common peripheral vertigo and the posterior and/or lateral semicircular canals are usually affected. BPPV is characterized by brief attacks of rotatory vertigo associated with positional and/or positioning nystagmus, which are elicited by specific head positions or changes in head position relative to gravity. In patients with the posterior-canal-type of BPPV, torsional nystagmus is induced by the Dix-Hallpike maneuver. In patients with the lateral-canal-type of BPPV, horizontal geotropic or apogeotropic nystagmus is induced by the supine roll test. The pathophysiology of BPPV is canalolithiasis comprising free-floating otoconial debris within the endolymph of a semicircular canal, or cupulolithiasis comprising otoconial debris adherent to the cupula. The observation of positional and/or positioning nystagmus is essential for the diagnosis of BPPV. BPPV is treated with the canalith repositioning procedure (CRP). Through a series of head position changes, the CRP moves otoconial debris from the affected semicircular canal to the utricle. In this review, we provide the classification, diagnostic criteria, and examinations for the diagnosis, and specific and non-specific treatments of BPPV in accordance with the Japanese practical guidelines on BPPV published by the Japan Society for Equilibrium Research.

Persistent Down-Beating Torsional Positional Nystagmus: Posterior Semicircular Canal Light Cupula?

A 16-year-old boy with rotatory positional vertigo and nausea, particularly when lying down, visited our clinic. Initially, we observed vertical/torsional (downward/leftward) nystagmus in the supine position, and it did not diminish. In the sitting position, nystagmus was not provoked. Neurological examinations were normal. We speculated that persistent torsional down-beating nystagmus was caused by the light cupula of the posterior semicircular canal. This case provides novel insights into the light cupula pathophysiology.

How Were Eye Movements Recorded Before Yarbus?

Alfred Yarbus introduced a new dimension of precision in recording how the eyes moved, either when attempts were made to keep them stationary or when scanning pictures. Movements of the eyes had been remarked upon for millennia, but recording how they move is a more recent preoccupation. Emphasis was initially placed on abnormalities of oculomotor function (like strabismus) before normal features were considered. The interest was in where the eyes moved to rather than determining how they got there. The most venerable technique for examining ocular stability involved comparing the relative motion between an afterimage and a real image. In the late 18th century, Wells compared afterimages generated before body rotation with real images observed following it when dizzy; he described both lateral and torsional nystagmus, thereby demonstrating the directional discontinuities in eye velocities. At around the same time Erasmus Darwin used afterimages as a means of demonstrating ocular instability when attempting to fixate steadily. However, the overriding concern in the 19th century was with eye position rather than eye movements. Thus, the characteristics of nystagmus were recorded before those of saccades and fixations. Eye movements during reading were described by Hering and by Lamare (working in Javal's laboratory) in 1879; both used similar techniques of listening (with tubes placed over the eyelids) to the sounds made during contractions of the extraocular muscles. Photographic records of eye movements during reading were made by Dodge early in the 20th century, and this stimulated research using a wider array of patterns. Eye movements over pictures were examined by Stratton and later by Buswell, who drew attention to the effects of instructions on the pattern of eye movements. In midcentury, attention shifted back to the stability of the eyes during fixation, with the emphasis on involuntary movements. The suction cap methods developed by Yarbus were applied with some success to recording the perceptual effects of retinal image stabilization. It is an historical irony that the accuracy of image stabilization with contact lenses was assessed by comparison with the oldest method for examining eye movements--afterimages.

Audiovestibular impairments associated with intracranial hypotension

ObjectiveTo investigate the patterns and mechanisms of audiovestibular impairments associated with intracranial hypotension. MethodsWe had consecutively recruited 16 patients with intracranial hypotension at the Neurology Center of Pusan National University Hospital for two years. Spontaneous, gaze-evoked, and positional nystagmus were recorded using 3D video-oculography in all patients, and the majority of them also had pure tone audiometry and bithermal caloric tests. ResultsOf the 16 patients, five (31.3%) reported neuro-otological symptoms along with the orthostatic headache while laboratory evaluation demonstrated audiovestibular impairments in ten (62.5%). Oculographic analyses documented spontaneous and/or positional nystagmus in six patients (37.5%) including weak spontaneous vertical nystagmus with positional modulation (n=4) and pure positional nystagmus (n=2). One patient presented with recurrent spontaneous vertigo and tinnitus mimicking Meniere's disease, and showed unidirectional horizontal and torsional nystagmus with normal head impulse tests during the attacks. Bithermal caloric tests were normal in all nine patients tested. Audiometry showed unilateral (n=6) or bilateral (n=1) sensorineural hearing loss in seven (53.8%) of the 13 patients tested. ConclusionsIntracranial hypotension frequently induces audiovestibular impairments. In addition to endolymphatic hydrops and irritation of the vestibulocochlear nerve, compression or traction of the brainstem or cerebellum due to loss of CSF buoyancy may be considered as a mechanism of frequent spontaneous or positional vertical nystagmus in patients with intracranial hypotension.

EHMTI-0320. Orthostatic headache and audiovestibular dysfunction associated with intracranial hypotension

Results Out of the 16 patients with intracranial hypotension, five (31%) had neuro-otological symptoms along with the orthostatic headache. One of them presented with recurrent spontaneous vertigo and tinnitus mimicking meniere’s disease (MD). Oculographic analysis documented abnormal eye movements in 38%, which include spontaneous downbeat nystagmus with variable positional modulation (n = 3, 19%) and positional upbeat nystagmus (n = 3, 19%). During the attack of vertigo in the patient with MD-like symptoms, we observed unidirectional horizontal and torsional nystagmus with normal head impulse test. Bithermal caloric tests were normal in all patients who tested. Audiometry showed unilateral or bilateral sensorineural hearing loss in about half of the patients. Conclusions Our study demonstrates that intracranial hypotension can induce higher frequency of audiovestibular dysfunction, which may be attributed to both irritation or dysfunction of the peripheral labyrinth or vestibulocochlear nerve, and brainstem or cerebellar dysfunction due to brain sagging. No conflict of interest.

Lhermitte–Duclos disease presenting with atypical positional nystagmus

We describe a patient with dysplastic cerebellar gangliocytoma (Lhermitte–Duclos disease) who presented with an acute onset of positional disequilibrium. Video-oculography in the right Hallpike position revealed rightward torsional down-beat nystagmus, initially thought to be right anterior canal benign positional vertigo. However, the presence of spontaneous nystagmus, the persistent character of the positional nystagmus and the absence of fatigability indicated central positional nystagmus, attributable to his right-sided Lhermitte–Duclos disease. These findings emphasise the need for clinicians to reconsider a central cause before diagnosing the rare anterior canal benign positioning vertigo variant.

Onset of Positional Vertigo During Exposure to Combined G Loading and Chest-to-Spine Vibration

Aerospace environments commonly expose pilots to vibration and sustained acceleration, alone and in combination. Of 16 experimental research participants, 3 reported symptoms of vertigo and signs of torsional nystagmus during or shortly following exposure to sustained chest-to-spine (+3.8 Gx) acceleration (G loading) and chest-to-spine (0.5 g(x)) vibration in the 8-16 Hz band. Two of the participants reported intermittent vertigo for up to 2 wk, were diagnosed with benign paroxysmal positional vertigo (BPPV), and were treated successfully with the Epley Maneuver. On a follow-up survey, a third participant reported transient BPPV-like vertigo, which resolved spontaneously. The follow-up survey also prompted participants to self-report other effects following research protocol exposure to vibration and G loading, revealing details about other minor and transient, but more common, effects that resolved within 3 h. Our studies indicated a significantly elevated incidence of BPPV following exposure to vibration plus G loading compared to vibration alone that was positively correlated with participant age. One mechanism for the rolling sensation in BPPV involves broken or dislodged otoconia floating within one of the posterior semicircular canals, making the canal gravity-sensitive. Our observations highlight a heretofore unforeseen risk of otolith damage sustained during launch, undetectable in space, potentially contributing to vertigo and perceived tumbling upon re-entry from microgravity.

Torsional nystagmus in hypothalamic hamartoma

Torsional nystagmus was noted in a patient with hypothalamic hamartoma. Magnetic resonance imaging revealed an exophytic hypothalamic mass extending into the pre-pontine cistern and abutting ventral mesencephalon. The quickphase of the torsional nystagmus was directed towards the left side, ipsilateral to the side of compression by the hamartoma. Ipsi-lesionally directed pure torsional nystagmus in this case is attributed to the compressive lesion of ocular motor structures responsible for the neural integration of torsional and vertical eye movements, the interstitial nucleus of Cajal. [Published with video sequences].

Progressive ataxia with oculo-palatal tremor and optic atrophy

A 42-year-old man of Polish extraction presented with a four year history of slowly deteriorating reading difficulties and gait imbalance. There was no evidence for alcohol or recreational substance abuse. Family history was unremarkable. On examination he had tandem gait ataxia. Power was normal and with no atrophies. Deep tendon reflexes were pronounced on the left with ipsilaterally extensor plantar response. He had upper limb past pointing, pronounced on the left. Visual acuity was 20/60 on the right and 20/80 on the left. Colour vision (Ishihara plates): 13/15 on the right and 10/15 on the left. Humphrey 10:2 perimetry showed reduced sensitivity paracentrally in both eyes. Retinae appeared normal, however both optic discs showed temporal wedge-shaped pallor (Fig. 1). Examination of extraocular movements was supported by binocular 3D video oculography (video 1). Pendular torsional nystagmus in primary gaze was detected, partly attenuated on left gaze. The nystagmus had two components, a baseline, low amplitude (1 –2 ), symmetrical, pendular, torsional oscillation (1.7–2 Hz), and an irregular larger amplitude (2 –5 ) nystagmus beating clockwise from the observer’s point of view. Both nystagmus components were pronounced in the right eye. The torsional faster component included a large upwards component in the right eye (‘left pendular hemiseesaw nystagmus’) [1] (Fig. 1). Non-periodic tremor (2 Hz) of the soft palate and posterior pharyngeal wall muscles was evident (video 2). Optical coherence tomography of the peripapillary retinal nerve fibre layer confirmed bilateral segmental optic atrophy (Fig. 1). Full-field and multifocal electroretinograms were normal. Amplitudes of pattern reversal visual evoked potentials were bilaterally borderline reduced. Haematology and biochemistry indices were normal as were vitamin B12, folic acid, thyroid function, syphilis and HIV 1/2 serology, and screening for onconeuronal and other auto-antibodies. Cerebrospinal fluid analysis was normal. Full GFAP gene sequencing failed to support the presence of Alexander’s disease [2]. Search for spinocerebellar ataxia expansions and/or duplications 1–3, 6, 7, 12 and 20 was negative [3, 4] as were searches for mitochondrial mutations associated with (1) Leber’s hereditary optic atrophy [5], (2) mitochondrial encephalomyopathy,lactic acidosis and stroke-like episodes, (3) myoclonic Electronic supplementary material The online version of this article (doi:10.1007/s00415-013-7136-3) contains supplementary material, which is available to authorized users.

Autosomal-dominant nystagmus, foveal hypoplasia and presenile cataract associated with a novel PAX6 mutation

Autosomal-dominant idiopathic infantile nystagmus has been linked to 6p12 (OMIM 164100), 7p11.2 (OMIM 608345) and 13q31-q33 (OMIM 193003). PAX6 (11p13, OMIM 607108) mutations can also cause autosomal-dominant nystagmus, typically in association with aniridia or iris hypoplasia. We studied a large multigenerational white British family with autosomal-dominant nystagmus, normal irides and presenile cataracts. An SNP-based genome-wide analysis revealed a linkage to a 13.4-MB region on chromosome 11p13 with a maximum lod score of 2.93. A mutation analysis of the entire coding region and splice junctions of the PAX6 gene revealed a novel heterozygous missense mutation (c.227C>G) that segregated with the phenotype and is predicted to result in the amino-acid substitution of proline by arginine at codon 76 p.(P76R). The amino-acid variation p.(P76R) within the paired box domain is likely to destabilise the protein due to steric hindrance as a result of the introduction of a polar and larger amino acid. Eye movement recordings showed a significant intrafamilial variability of horizontal, vertical and torsional nystagmus. High-resolution in vivo imaging of the retina using optical coherence tomography (OCT) revealed features of foveal hypoplasia, including rudimentary foveal pit, incursion of inner retinal layers, short photoreceptor outer segments and optic nerve hypoplasia. Thus, this study presents a family that segregates a PAX6 mutation with nystagmus and foveal hypoplasia in the absence of iris abnormalities. Moreover, it is the first study showing detailed characteristics using eye movement recordings of autosomal-dominant nystagmus in a multigenerational family with a novel PAX6 mutation.

Anterior semicircular canal benign paroxysmal positional vertigo: A series of 20 patients

The purpose of this study is to define the diagnostic criteria for anterior semicircular canal benign paroxysmal positional vertigo (BPPV) based on clinical data and the available anatomical and pathophysiological data. Between July 2006 and June 2007, 4320 patients consulting for otoneurological disease were investigated by otological examination, videonystagmography and neurological examination. BPPV was diagnosed in 1430 patients, involving the posterior semicircular canal in 1325 patients, the horizontal semicircular canal in 85 patients, the posterior semicircular canal and ipsilateral anterior (superior) semicircular canal in 19 patients and the anterior semicircular canal only in one patient. In the 20 patients with anterior semicircular canal BPPV, the Dix-Hallpike (DH) test induced ageotropic horizontal torsional nystagmus beating towards the uppermost ear in the lateral supine position with reversal on standing. The modified Epley manoeuvre was effective in 94.1% of cases on the 8th day and in 97.5% of cases at 1 month. Nystagmus beating towards the uppermost ear on the DH test is consistent with BPPV involving the anterior semicircular canal of the uppermost ear. The torsional component of nystagmus and not just the vertical component must be taken into account to facilitate the diagnosis with videonystagmoscopy glasses and identify the affected side. The anterior semicircular canal is rarely affected due to its anatomical position. Settling of otoconia in this canal requires hyperextension of the head. Treatment is simple, consisting of the modified Epley particle repositioning manoeuvre.

Facial Palsy and Nystagmus after Transvenous Embolization of a Carotid Cavernous Fistula

Facial Palsy and Nystagmus after Transvenous Embolization of a Carotid Cavernous Fistula