Atypical Positional Vertigo: Definition, Causes, and Mechanisms

Telemedicine: Inter-Method Agreement Between In-Person Consultations and Video Recordings When Diagnosing Benign Paroxysmal Positional Vertigo

Objective: To investigate the inter-method agreement between in-person consultations and video recordings when diagnosing BPPV. Methods: Two experienced vestibular clinicians (clinician A and B) evaluated patients for the presence and type of BPPV, using the TRV chair (Interacoustics, Middlefart, DK), at a tertiary referral center. During these in-person consultations, diagnostic maneuvers and eye movements were recorded, and a diagnosis was made. Both clinicians independently evaluated their cases again, during two video review sessions (Video Review 1 and Video Review 2). These sessions were conducted one month apart. Both clinicians were blinded to patient information and medical history during the analysis and did not have access to sound recordings. They were asked to provide a new diagnosis, based on the videos alone. Inter-method and intra-observer agreement for BPPV diagnoses between in-person consultations and video reviews were assessed using the percentage of agreement and Cohen's kappa. An independent analysis of all patients' eye movements was conducted to identify patterns that might have influenced agreement between in-person consultation diagnoses and the two video reviews by clinicians. Results: During the in-person consultations, each clinician evaluated 100 patients. Clinician A diagnosed BPPV in 40% of the cases, while clinician B diagnosed it in 19% of the cases. Considering the inter-method agreement, clinician A agreed on 81% (95% CI (73, 89)) and 77% (95% CI (69, 85)) of the cases with associated kappa coefficients of 0.67 (95% CI (0.55, 0.79)) and 0.63 (95% CI (0.51, 0.75)) between in-person consultations and Video Reviews 1 and 2, respectively. For clinician B, the percentages of agreement were, respectively, 86% (95% CI (79, 93)) and 84% (95% CI (77, 91)), with corresponding kappa coefficients of 0.55 (95% CI (0.36, 0.74)) and 0.51 (95% CI (0.32, 0.70)). As for the intra-observer agreement, clinician A achieved an intra-observer agreement of 84% (95% CI (77, 91)) with kappa = 0.74 (95% CI (0.63, 0.85)), while clinician B achieved a slightly higher intra-observer agreement of 90% (95% CI (84, 96)) with kappa = 0.67 (95% CI (0.51, 0.83)). Descriptive analysis of the eye movement revealed that both clinicians showed high diagnostic consistency for "no BPPV" in cases without provoked nystagmus (78/86, 91%) even when spontaneous nystagmus was present, and for posterior canal BPPV (37/78, 47%) when characteristic nystagmus was observed. However, disagreement was noted for horizontal canal BPPV (15 cases) and in scenarios with subjective BPPV (2 cases) or purely vertical nystagmus (11/31 cases, 35%). Conclusions: This study showed the feasibility of using video recordings when diagnosing BPPV. It demonstrates that BPPV might be reliably diagnosed in a telemedicine setting. However, careful consideration must be given to certain factors during the protocol's design to improve the diagnostic process.

Variants of posterior semicircular canal involvement in benign paroxysmal positional vertigo

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

Inversion Test and Sitting-Up Oculomotor Patterns in Patients with Graviceptive Heavy Posterior Cupula - A Case Series

A graviceptive heavy posterior cupula typically results from cupulolithiasis and clinically manifests as short vertigo spells when the head moves in the provocative position. Half-Hallpike test (HHT) in posterior cupulolithiasis (PSC-BPPV-cu) elicits an upbeating ipsitorsional nystagmus (UBITN), which lasts more than a minute as per the consensus criteria developed by the Barany Society. In the last decade, cases with canalolithiasis in the short arm of the posterior semicircular canal (PSC-BPPV-sa), wherein the otoconial debris falls on the utricular side of the posterior cupula on getting up from supine, rendering it heavy (graviceptive), have been reported. Such patients complain of sitting-up vertigo, associated with a constant disequilibrium, and anteroposterior truncal oscillations are recorded by ad hoc posturography in many of these patients. The oculomotor patterns generated in such patients during the HHT may be identical to those resulting from PSC-BPPV-cu. Rarely do the two conditions (PSC-BPPV-cu and PSC-BPPV-sa) coexist. Nine cases of graviceptive heavy cupula were diagnosed at our center over a period of 6 months from September 1, 2022, to March 31, 2023, with their characteristic diagnostic oculomotor patterns, distinguishing features, and management discussed. We propose a grading system for the inversion test during the HHT that reliably distinguishes PSC-BPPV-cu from PSC-BPPV-sa, as well as when the two conditions coexist.

Paroxysmal Positional Nystagmus in Acoustic Neuroma Patients

The association between acoustic neuroma and positional vertigo with paroxysmal positional nystagmus is relatively rare, but, when present, it certainly represents a challenge for the otoneurologist. There are few reports in the literature on this particular issue, and some questions are still unanswered, particularly regarding the characteristics of positional nystagmus that may distinguish between a true benign paroxysmal vertigo and a positional nystagmus associated with the tumor. We present the videonystagmographic patterns of seven patients with acoustic tumor who had paroxysmal positional nystagmus and analyzed its features. A concomitant true benign paroxysmal positional vertigo may be present during the follow-up of a non-treated patient, as the paroxysmal positional vertigo may be the first symptom of the tumor, and it may show characteristics that are very similar to a posterior semicircular canal canalolithiasis or a horizontal canal "heavy or light cupula". The possible mechanisms are discussed.