Anatomy
The localized expansion at the base of the posterior semicircular canal that houses the cupula and sensory hair cells.
Ampulla
What is the primary mechanical distinction between canalithiasis and cupulolithiasis?
Otoconia adhere directly to the Cupula rather than float freely in the canal fluid
This specific condition affecting the posterior semicircular canal which is characterized by otolithic debris adhered to the cupula
Cupulolithiasis of the posterior canal (PC-BPPV-cu)
If you see down beating nystagmus with BPPV, what canal is involved?
Anterior canal
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This specific semicircular canal is the most common anatomical site affected by both canalithiasis and cupulolithiasis.
Posterior Semicircular Canal
What is the fundamental force that the cupula abnormally becomes sensitive to when loaded with dense otoconia?
Gravity (making the cupula a gravity-sensitive receptor)
During the therapeutic head-shaking maneuver evaluated in this study, the patient’s head is pitched forward by this specific angle before lateral movement?
30 degrees
To clinically distinguish cupulolithiasis from canalolithiasis, you look at the onset of nystagmus where usually canalolithiasis typically has a brief delay (latency), whereas cupulolithiasis features this characteristic instead?
This anatomical conduit is created by the junction of the anterior and posterior semicircular canals as they merge together back into the vestibule
Common crus
This is the specific gelatinous, sensory barrier structure located inside the ampulla where otoconia become abnormally stuck in cupulolithiasis.
Cupula
This describes the latency period of vertigo onset when a patient with cupulolithiasis enters a provoking position.
Immediate onset/no latency period
This primary endpoint measured the short-term resolution rate of positional vertigo and nystagmus evaluated at this specific time point after treatment.
The following day/24 hours later
A hallmark feature of BPPV-indicted nystagmus is that it features a temporary delay before starting when the head is moved into the provocative position, what is this delay called?
Latency
A disorder where there is an inadequate amount of bone covering the superior semicircular canals in the inner ear.
Superior Canal Dehiscence Syndrome
The specific otolith organ where the calcium carbonate crystals originally detach before migrating into the posterior canal.
Utricle
This is the typical duration of nystagmus and vertigo in cupulolithiasis while maintaining a provoking head position.
Persistent or sustained, lasting >1 minute or as long as the position is held
In the intention-to-treat analysis for the primary outcome, this exact percentage of patients in the head-shaking group showed resolution of vertigo and nystagmus the following day.
37.7%
This is the approximate percentage range that accounts for posterior cupulolithiasis of all BPPV cases.
1% - 6%
Remembering also that approximately 5% - 10% of posterior canal variants
What does an Abnormal Head Impulse test mean?
- The patient was unable to maintain fixation on a target during a rapid head turn, requiring a corrective saccade to catch up to the target
- Example: if we turn a patient’s head rapidly to the left and their eyes are dragged off target to the left, followed by a corrective saccade back to the right to re-fixate on our nose, we would document this as a positive (abnormal) head impulse test to the left
These specialized cellular projections embedded within the gelatinous cupula convert mechanical deflection into electrical neural pathways.
Kinocilia and Stereocilia
The distinct multi-directional pattern of nystagmus observed during a positive Dix-Hallpike test for a patient with left posterior cupulolithiasis.
Persistent left-torsional, upbeating nystagmus
The anatomical and biomechanical reason why the head-shaking maneuver achieves lower immediate efficacy in posterior canal cupulolithiasis compared to horizontal canal cupulolithiasis.
The posterior tilting of the posterior canal ampulla which results in less mechanical inertia being transferred to the cupula
When performing the supine roll rest for horizontal canal cupulolithiasis, the provoked nystagmus beats toward the ceiling, a characteristic known by this specific term.
Apogeotropic nystagmus
This chronic functional dizziness disorder is often misdiagnosed as BPPV or vestibular hypofunction, but patients report persistent unsteadiness triggered by upright posture, walking, or complex visual environments without objective signs of vestibular loss.
Persistent Postural-Perceptual Dizziness (PPPD)