The semicircular canals are responsible for sensing angular head motion in three-dimensional space and for providing neural inputs to the central nervous system (CNS) essential for agile mobility, stable vision, and autonomic control of the cardiovascular and other gravity-sensitive systems. Sensation relies on fluid mechanics within the labyrinth to selectively convert angular head acceleration into sensory hair bundle displacements in each of three inner ear sensory organs. Canal afferent neurons encode the direction and time course of head movements over a broad range of movement frequencies and amplitudes. Disorders altering canal mechanics result in pathological inputs to the CNS, often leading to debilitating symptoms. Vestibular disorders and conditions with mechanical substrates include benign paroxysmal positional nystagmus, direction-changing positional nystagmus, alcohol positional nystagmus, caloric nystagmus, Tullio phenomena, and others. Here, the mechanics of angular motion transduction and how it contributes to neural encoding by the semicircular canals is reviewed in both health and disease.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6520623 | PMC |
http://dx.doi.org/10.1152/jn.00708.2018 | DOI Listing |
Acta Otolaryngol
January 2025
Department of Otorhinolaryngology-Head and Neck Surgery, College of Medicine, Kyung Hee University, Seoul, Korea.
Background: The Canalith Repositioning Maneuver (CRM) is often ineffective for persistent geotropic direction-changing positional nystagmus (DCPN). In these cases, determining the lesion side can be challenging, as the null plane side and the side with stronger nystagmus on the roll test are frequently opposite.
Objectives: This study investigates whether the low therapeutic efficacy of CRM in persistent DCPN could be attributed to incorrect determination of the lesion side.
Acta Otolaryngol
January 2025
Department of Neurology, the First Hospital of Hebei Medical University, Shijiazhuang, Hebei, China.
Background: Currently, there is a paucity of research comparing the clinical characteristics and repositioning efficacy between posterior canal-benign paroxysmal positional vertigo-canalolithiasis (PC-BPPV-ca) and posterior canal-benign paroxysmal positional vertigo-cupulolithiasis (PC-BPPV-cu).
Aims/objectives: To observe the clinical characteristics and compare the efficacy of repositioning maneuvers between PC-BPPV-ca and PC-BPPV-cu patients.
Material And Methods: Clinical information of patients was collected.
Eur Arch Otorhinolaryngol
January 2025
Hospital QuironSalud Infanta Luisa, Seville, Spain.
Front Neurol
December 2024
Department of Neurology, Dongzhimen Hospital Affiliated to Beijing University of Chinese Medicine, Beijing, China.
Objective: The objective of the study is to analyze and explore the characteristics of the video head impulse test (vHIT) for light cupula in the idiopathic horizontal semicircular canal and compare them with those of horizontal semicircular canal cupulolithiasis (HC-cu) in order to investigate the potential mechanism involved.
Methods: Data from 51 cases of idiopathic light cupula and 42 cases of horizontal semicircular canal cupulolithiasis were retrospectively analyzed. The positional nystagmus features, vHIT anomaly rate, gain value, saccades, and other indicators were compared.
Clin Exp Otorhinolaryngol
December 2024
Department of Otorhinolaryngology-Head and Neck Surgery, Incheon St. Mary's Hospital, College of medicine, The Catholic University of Korea, Seoul, Republic of Korea.
Background: Lateral semicircular canal BPPV (LC-BPPV) is diagnosed by the head roll test (HRT), in which the head is rotated to move particles in the lateral canal, causing nystagmus. The body roll test (BRT) is performed in a rolling position with the body and head together, which has the advantage of safely rotating the head at the correct angle in both directions. This study aims to assess the diagnostic utility of the body roll test (BRT).
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!