Feasibility of Using the Video-Head Impulse Test to Detect the Involved Canal in Benign Paroxysmal Positional Vertigo Presenting with Positional Downbeat Nystagmus. Usefulness of the video head impulse test. Balance disorders in childhood: Main etiologies according to age. Combined horizontal and posterior canal benign paroxysmal positional vertigo in three patients with head trauma. Benign Paroxysmal Positional Vertigo: Differential Diagnosis in Children. Atypical Benign Paroxysmal Positional Vertigo in a Case of Acoustic Neuroma. ![]() Topodiagnosis of the Inner Ear: Illustrative Clinical Cases. Downbeating Nystagmus in Benign Paroxysmal Positional Vertigo: An Apogeotropic Variant of Posterior Semicircular Canal. Posterior semicircular canal benign paroxysmal positional vertigo presenting with torsional downbeating nystagmus: An apogeotropic variant. Natural course of positional down-beating nystagmus of peripheral origin. Direction-fixed paroxysmal nystagmus lateral canal benign paroxysmal positioning vertigo (BPPV): Another form of lateral canalolithiasis. Revised criteria for suspicion of non-benign positional vertigo. Diagnostic criteria for central versus peripheral positioning nystagmus and vertigo: A review. Role of semicircular canals in positional alcohol nystagmus. Typical and atypical benign paroxysmal positional vertigo: Literature review and new theoretical considerations. Benign Paroxysmal Positional Vertigo and Positional Vertigo Variants. Benign paroxysmal positional vertigo: Diagnostic criteria Consensus document of the Committee for the Classification of Vestibular Disorders of the Bárány Society. The authors declare no conflict of interest. The nystagmus it presents is similar to that of phase 1 positional alcohol nystagmus, in which the cupula is relatively lighter than the endolymph, as alcohol, which is less dense than water, enters the cupula quicker than the endolymph. There are many theories that explain why the cupula becomes lighter than the endolymph but only in the lateral canal, including the following: light debris attached to the cupula a reduced cupula density as compared to normal endolymphatic density due to an altered homeostasis of sulphated proteoglycans, which are synthesized in the cupula an increase in endolymphatic density due to chemical changes and a difference between perilymphatic and endolymphatic densities. Their pathogenesis is still unknown, and they are generally considered pathologic vestibular phenomena. Light Cupula Syndromeĭespite the fact that positional vertigo and nystagmus caused by light cupula are similar to BPPV, it has not yet been determined if they are a variant of BPPV. ![]() In their 2011 paper, they mentioned that patients with a heavy cupula diagnosis responded to repositioning maneuvers, while light cupula patients did not. ![]() hypothesized that a heavy cupula would actually be more of an otoconial phenomenon than a gravitational change and set forth the possibility of a phenomenon in which particles float (“buoyancy”) in the horizontal canal, contrary to what happens in a light cupula, in which there would be an increase of endolymphatic density. However, if the density of the cupula becomes heavier or lighter as compared to that of the endolymph, its deflection due to the presence of otolith remains (debris) alters its gravitational sensitivity. Under normal conditions, the semicircular canals do not depend on gravity, taking into account that the cupula and the endolymph have the same density and therefore the same gravity. Some authors have proposed that the density of the cupula would increase as regards the endolymphatic density, thus producing an ampullofugal deflection that would facilitate the persistence of the position-changing apogeotropic nystagmus, depending on the cephalic position. A heavy cupula is characterized by the presence of persistent (lasting longer than a minute) apogeotropic positional nystagmus with cephalic changes and of a null point.
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