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Introduction: Detection of torsional nystagmus can help identify the canal of origin in benign paroxysmal positional vertigo (BPPV). Most currently available pupil trackers do not detect torsional nystagmus. In view of this, a new deep learning network model was designed for the determination of torsional nystagmus. Methods: The data set comes from the Eye, Ear, Nose and Throat (Eye&ENT) Hospital of Fudan University. In the process of data acquisition, the infrared videos were obtained from eye movement recorder. The dataset contains 24521 nystagmus videos. All torsion nystagmus videos were annotated by the ophthalmologist of the hospital. 80% of the data set was used to train the model, and 20% was used to test. Results: Experiments indicate that the designed method can effectively identify torsional nystagmus. Compared with other methods, it has high recognition accuracy. It can realize the automatic recognition of torsional nystagmus and provides support for the posterior and anterior canal BPPV diagnosis. Discussion: Our present work complements existing methods of 2D nystagmus analysis and could improve the diagnostic capabilities of VNG in multiple vestibular disorders. To automatically pick BPV requires detection of nystagmus in all 3 planes and identification of a paroxysm. This is the next research work to be carried out.

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Background: Vestibular 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. Objective: To describe new mechanisms of action for the sitting-up vertigo BPPV variant. Methods: Eighteen 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. Results: All 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). Conclusions: Persistent 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.

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A 17-year-old girl with relapsing-remitting multiple sclerosis (MS) was referred for a 2-year history of visual blurriness. Her bedside examination was remarkable for gait unsteadiness only. Optical coherence tomography was performed as part of her workup. Unexpectedly, Spectralis© video imaging revealed left torsional nystagmus that was not apparent on bedside examination. Review of previous brain magnetic resonance images (MRI) revealed left ocular deviation, as well as a left dorsolateral medullary MS plaque, which was the cause of her torsional nystagmus. We highlight how Spectralis© scanning confocal laser ophthalmoscopy allows video imaging that can capture torsional ocular movements.

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Vertebrobasilar dolichoectasia (VBD) is a rare dilative arteriopathy defined as elongation or widening of the intracranial vertebral and/or basilar arteries. The prevalence ranges from 0.06% to 5.8%. The majority of VBDs are asymptomatic. Downbeat nystagmus has been reported as a component of an infrequent ocular movement disorder in VBD. Nevertheless, oculopalatal tremor (OPT), delayed sequelae of a brainstem lesion, has never been demonstrated in VBD cases. Synchronized rhythmic involuntary contractions of the soft palate with an ocular pendular nystagmus, predominantly vertical pendular nystagmus, are the hallmark presentation. Our case demonstrated a 50-year-old female who presented with 3-month history of oscillopsia. Examination showed binocular conjugate torsional jerk nystagmus simultaneous with a contraction of the soft palate, defined as an atypical OPT, resulting from dolichoectatic left vertebral artery compressing on medulla, demonstrated by magnetic resonance imaging. Bilateral conjugate torsional jerk nystagmus simultaneous with palatal tremor, considering as an atypical OPT, should be included as one of the symptomatic presentations of vertebral artery dolichoectasia in spite of its rarity.

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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.

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OBJECTIVES: 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. MATERIAL AND METHOD: Between July 2006 and June 2007, 4320 patients consulting for otoneurological disease were investigated by otological examination, videonystagmography and neurological examination. RESULTS: 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. DISCUSSION/CONCLUSION: 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.

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