The Half Hallpike Test compliments the Dix Hallpike Test and is traditionally used to assist with the diagnosis of posterior canal-benign paroxysmal positional vertigo (BC-BPPV), cupulolithiasis, as it may produce a greater degree of deflection under the action of gravity without latency when the otoconia are adhered to the cupula [1]. Short-arm PC BPPV may also result in nystagmus which follow excitatory patterns, as the weight of the dislodged otoconia trapped in the utricular side of the PC can lead to ampullofugal endolymph movement [2]. A test is positive when a patient reports vertigo, dizziness, or sensation of movement or falling with nystagmus present. When the head is in this position, it allows the PC to be aligned with the gravitational vector, which causes movement of otoconial debris through the posterior canal. Otoconia within the long-arm of the PC cause excitation (ampullofugal direction of endolymph) and lead to nystagmus generation (upbeat and ipsitorsional). Otoconia within the short-arm of the PC may also cause excitation (ampullofugal direction of endolymph) and lead to nystagmus generation (upbeat and ipsitorsional).
Date
2023-06
References
[1] Wang W, Yan S, Zhang S, et al. Clinical application of different vertical position tests for posterior canal-benign paroxysmal positional vertigo-cupulolithiasis.Frontiers in neurology. 2022;13. https://doi.org/10.3389/fneur.2022.930542; [2] Scocco DH, Barreiro MA, García IE. Sitting-up vertigo as an expression of posterior semicircular canal heavy cupula and posterior semicircular canal short arm canalolithiasis.Journal of otology. 2022;17(2):101-106. https://doi.org/10.1016/j.joto.2022.02.001