Resolution of atypical posterior semicircular canal BPPV: evidence for putative short-arm location

Abstract

This case demonstrates the successful identification and treatment of atypical posterior semicircular canal benign paroxysmal positional vertigo (BPPV) based on a unique presentation of positional nystagmus, the resultant nystagmus from repositioning manoeuvers, and restored function of the affected semicircular canal. This case illustrates the importance of completing a comprehensive clinical examination and the value for incorporating the video head impulse test as well as adjusting treatment based on testing and patient response when managing variant cases of BPPV.

Case Report: Keep your eyes open! Nystagmus guides atypical BPPV

“…It is possible the otoconia from the left posterior semicircular canal were located within its short arm. Ping et al ( 13 ) and later Ludwig and Schubert ( 1 ) reported excitatory nystagmus due to putative short-arm posterior canal BPPV. Residual otoconia in the short arm of the posterior canal following treatment could also account for the downbeat nystagmus observed in left DHT after treatment, although that is unlikely as she did not report vertigo.…”

“…Variants of benign paroxysmal positional vertigo (BPPV) such as sitting up vertigo, short-arm posterior canal BPPV, and type II BPPV may present with atypical nystagmus patterns or even absent nystagmus that can be difficult for clinicians to manage and cause longer durations of morbidity ( 1 , 2 ). This case series presents four cases of unique BPPV presentations that highlight the clinical means to appropriately identify the affected semicircular canal based on nystagmus patterns that include comparing the intensity of nystagmus in different head positions, changing gaze direction (eye in orbit) to accentuate vertical or torsional components, and identifying canal-specific nystagmus patterns independently of the positioning test being performed.…”