Related Experiment Video
Updated: Feb 11, 2026
08:38
Testing of all Six Semicircular Canals with Video Head Impulse Test Systems
Published on: April 18, 2019
32.8K
[Horizontal canal benign paroxysmal positional vertigo--its affected side and horizontal semicircular canal function]
Nobuya Fujita1, Toshiaki Yamanaka, Hideyuki Okamoto
1Department of Otolaryngology, Nara Medical University, Nara University.
Nihon Jibiinkoka Gakkai Kaiho
|April 15, 2005
Summary
This study investigates horizontal canal benign paroxysmal positional vertigo (HC-BPPV), differentiating between canalolithiasis and cupulolithiasis. Findings suggest distinct mechanisms for caloric nystagmus in each subtype, impacting horizontal semicircular canal function assessment.
Area of Science:
- Neurology
- Otolaryngology
- Vestibular System
Context:
- Benign paroxysmal positional vertigo (BPPV) is a common cause of vertigo.
- Horizontal canal BPPV (HC-BPPV) presents unique diagnostic challenges.
- Understanding HC-BPPV pathophysiology is crucial for effective management.
Purpose:
- To elucidate the pathophysiology of HC-BPPV.
- To differentiate between canalolithiasis and cupulolithiasis in HC-BPPV.
- To analyze the function of the horizontal semicircular canal in HC-BPPV subtypes.
Summary:
- This study analyzed 13 HC-BPPV patients, classifying them into canalolithiasis (7) and cupulolithiasis (6).
- Caloric testing (CP) showed positive results in 54% of all patients, with higher rates in canalolithiasis (71%) than cupulolithiasis (33%).
- Distinct mechanisms for caloric nystagmus were proposed, involving endolymphatic fluid convection in canalolithiasis versus its absence in cupulolithiasis.
Impact:
- The findings offer insights into the differential diagnosis of HC-BPPV subtypes.
- Understanding the pathophysiology may lead to improved diagnostic accuracy for horizontal semicircular canal dysfunction.
- Further research with larger cohorts is needed to confirm the proposed mechanisms and refine diagnostic criteria.
Related Concept Videos
01:27Horizontal Gene Transfer
2.3K
Horizontal gene transfer (HGT) is a process where genetic material moves between organisms within the same generation, unlike vertical gene transfer, which occurs from parent to offspring. HGT plays a crucial role in microbial evolution, adaptation, and survival, particularly in shared environments like the human gut.Mobile genetic elements such as plasmids, prophages, integrons, insertion sequences, and transposons facilitate this process. HGT occurs through three primary mechanisms:...
2.3K
01:03Horizontal Curve: Problem Solving
418
A horizontal curve is characterized by its radius, intersection angle, and stationing of key points. In this case, the radius is 400 meters, and the angle of intersection is 30 degrees, with the station of the point of curvature (P.C.) at 0 + 150 meters. The goal is to determine the station values at the point of intersection (P.I.), point of tangency (P.T.), and midpoint of the curve, as well as the length of the long chord.The process begins with calculating the tangent distance (T) and the...
418
01:19Introduction to Horizontal Curves
745
Horizontal curves are essential in highway and railroad design, ensuring smooth and safe transitions between straight path segments, or tangents. These curves allow vehicles to maintain speed without abrupt changes, minimizing accidents and improving travel efficiency.A horizontal curve is typically defined by its geometric relationship to two tangents that meet at an intersection point (P.I.), where a simple curve is introduced to connect them. The back tangent refers to the initial tangent...
745
01:16Shear on the Horizontal Face of a Beam Element
531
To understand shear on the flat side of a prismatic beam element, consider the vertical and horizontal shearing forces, and the normal forces, acting on the element. The element's upper (U) and lower (L) sections, which are divided by the beam's neutral axis, are examined. The equilibrium of these forces is determined by applying the equilibrium equation, which helps identify the horizontal shearing force. This force is directly related to the bending moments and the cross-section's...
531
02:32Position-effect Variegation
7.1K
In 1928, a German botanist Emil Heitz observed the moss nuclei with a DNA binding dye. He observed that while some chromatin regions decondense and spread out in the interphase nucleus, others do not. He termed them euchromatin and heterochromatin, respectively. He proposed that the heterochromatin regions reflect a functionally inactive state of the genome. It was later confirmed that heterochromatin is transcriptionally repressed, and euchromatin is transcriptionally active chromatin.
7.1K
01:03Serial Position Effect
563
The serial position effect is a cognitive phenomenon where individuals are more likely to recall the first and last items in a list compared to those in the middle. This effect is divided into the primacy effect and the recency effect. The primacy effect is observed when the initial items in a list are remembered better. This occurs because these items are rehearsed more frequently or receive more elaborative processing, allowing them to be encoded into long-term memory more effectively. For...
563