Cupulolithiasis: A Critical Reappraisal

Abstract

Objective To review the history and pathophysiologic theories for cupulolithiasis and canalith jam in benign paroxysmal positional vertigo. Data Sources PubMed, Google Scholar. Review Methods Three PubMed and Google Scholar searches were performed, keywords: “cupulolithiasis,” “apogeotropic [and] benign,” and “canalith jam,” resulting in 187 unique full‐text articles in English or with English translation. Figures—Labyrinthine photographs were obtained of fresh utricles, ampullae, and cupulae of a 37‐day‐old mouse. Conclusions Freely moving otoconial masses explain most cases (>98%) of benign paroxysmal positional vertigo. Evidence that otoconia adhere strongly or persistently to the cupula is lacking. Apogeotropic nystagmus in the horizontal canal form is often attributed to cupulolithiasis; however, periampullary canalithiasis explains self‐limited nystagmus, and reversible canalith jam explains prolonged apogeotropic nystagmus. Treatment‐resistant cases can be explained by entrapment of particles in the canals or ampullae, but persistent adherence to the cupula remains theoretical. Implications for Practice Apogeotropic nystagmus is usually due to freely moving particles and should not be used in studies of horizontal canal benign paroxysmal positional vertigo as the sole method to define entrapment or cupulolithiasis. Caloric testing and imaging may help differentiate jam from cupulolithiasis. Treatment for apogeotropic benign paroxysmal positional vertigo should include maneuvers that rotate the head through 270° to fully clear the canal of mobile particles, using mastoid vibration or head shaking if entrapment is suspected. Canal plugging can be used for treatment failures.

Genome-Wide Association Study of Chronic Dizziness in the Elderly Identifies Loci Implicating MLLT10, BPTF, LINC01224, and ROS1

“…Based on > 7 million SNPs compared between the two studies, the only locus that demonstrated significantly different alleles was on chromosome 19. While the Ice/Fin/UKB/US study had a strong hit suggesting ZNF91, our fine mapping analysis identified a credible set of SNPs within nearby LINC01224 [60]. LINC01224 affects the transcription of ZNF91 by regulation of long-range interactions between the ZNF91 enhancer and promoter [61].…”

“…To focus on the chronic cochleovestibular disorder of aging, we also excluded non-vestibular system gait disorders such as Parkinson's and other ataxias. We also eliminated over 25,000 of those diagnosed with traumatic brain injury (TBI), since TBI is a strong predictor of vertigo that is presumed to have a separate etiology [60]. We used the ICD diagnosis of "dizziness" in an attempt to capture the most common complaint of chronic imbalance in the elderly, even though that may include some disorders originating outside the vestibule.…”

Residual dizziness after BPPV management: exploring pathophysiology and treatment beyond canalith repositioning maneuvers

“…Canalithiasis has been gradually accepted as the cause of most cases of BPPV (8), a process in which otoconia become detached from the otoconial membrane and fall into the semicircular canals before they can dissolve in the endolymph, hence transforming the affected canals into gravity-sensitive organs (9). Cupulolithiasis, in which freefloating endolymph debris adheres to the cupular membrane and renders the canal responsive to gravity (10) has been proposed to account for the remainder of BPPV cases, especially in older patients (10).…”

“…Cupulolithiasis, in which freefloating endolymph debris adheres to the cupular membrane and renders the canal responsive to gravity (10) has been proposed to account for the remainder of BPPV cases, especially in older patients (10). Clinical signs of cupulolithiasis have been defined as apogeotropic nystagmus, with new maneuvers developed to manage either utricular-or canal-side cupulolithiasis; however, evidence that otoconia adhere strongly or persistently to the cupula is lacking (8).…”

Effect of Vitamin D Deficiency on the Occurrence and Recurrence of Benign Paroxysmal Positional Vertigo: A Narrative Review

“…Cupulolithiasis is defined as the adherence of the otoconia debris or masses to the cupula which renders the gravity to be sensitive. However, there is no evidence that otoconia attach persistently or strongly to the cupula [18].…”