Unusual Locations of Benign Paroxysmal Positional Vertigo: Rare Entity or Regular Occurrence?

INTRODUCTION: According to the literature and our recent experience, even if patients present with symptoms strongly suggestive of benign paroxysmal positional vertigo (BPPV), the observed positional nystagmus does not always correspond to any previously described typical location. The aim of this multicentric study was to evaluate the frequency of both typical and less common forms of BPPV. MATERIAL AND METHODS: All consecutive patients presenting with BPPV in two hospitals between November 2016 and October 2017 were included. For each subject, answers to a standardized evaluation form and a recorded videonystagmoscopy were obtained by two otorhinolaryngologists. Appropriate diagnostic and therapeutic maneuvers were performed. RESULTS: A total of 532 patients were studied and 491 cases of typical BPPV were found: 370 cases of canalolithiasis of the posterior semicircular canal (SCC), 3 cases of canalolithiasis of the anterior SCC, 107 cases of canalolithiasis of the lateral SCC, and 11 cases of cupulolithiasis of the lateral SCC. Fourty one patients reported symptoms suggestive of BPPV with positional nystagmus that could correspond to unusual locations of otoconia in the SCC: 18 cases of canalolithiasis in the anterior ampulla of the lateral SCC, 16 cases of posterior short arm canalolithiasis, four cases of pseudo-spontaneous nystagmus in canalolithiasis of the lateral SCC, and three cases of canalolithiasis of the posterior third of SCC. DISCUSSION: Unusual BPPV accounted for almost 8% of BPPV treated in our clinics; it is paramount to know how to diagnose them, to carry out the appropriate therapeutic maneuvers and relieve these patients.

[How to manage vertigo in adult?] / Comment prendre en charge un vertige chez l'adulte ?

The interrogation and the clinical examination are critical in the research of vertigo etiology. In the context of vertigo, the vital emergencies are of neurological and vascular origins. It is therefore necessary to be able to identify them quickly and simply. Vertigo is a symptom to relieve and the cause is to be diagnosed. Careful questioning combined with neurological examination, nystagmus study, Halmagyi test and skew deviation search are more reliable than imaging in the first 48hours to detect a stroke. There are 12% false negatives in cerebral MRI and 74% false negative in cerebral CT-scan in the first 48hours of an ischemic stroke. Labyrinth emergencies are infectious labyrinthitis, perilymphatic fistula and aeroembolism of the vestibule.