Vestibular dysfunction in lateral semicircular canal dysplasia.

Area of Science:

• Otolaryngology
• Neuroscience
• Medical Imaging

Background:

• Lateral semicircular canal (LSCC) dysplasia is the most frequent inner ear malformation.
• The spectrum of LSCC dysplasia ranges from mild shortening to complete absence of the central bony island (CBI).
• The relationship between LSCC dysplasia and vestibular function deficits remains underexplored.

Purpose of the Study:

• To investigate the association between LSCC dysplasia and vestibular function.
• To compare vestibular function in patients with and without a central bony island (CBI) in the presence of LSCC dysplasia.

Main Methods:

• Retrospective analysis of 17 patients (23 ears) with LSCC dysplasia.
• Evaluation of vestibular function using caloric tests and video-head impulse tests (vHIT).
• Comparison of vestibular function parameters between ears with and without a central bony island (CBI).

Main Results:

• Abnormalities in caloric tests were found in 69% of patients, while 92% showed normal LSCC vestibulo-ocular reflex (VOR) gain on vHIT.
• A significant correlation was observed between caloric test slow-phase velocity and LSCC VOR gain (r=0.792, p=0.004).
• Ears without a central bony island (CBI) exhibited significantly lower slow-phase velocity and LSCC VOR gains compared to those with a CBI (p=0.001 and p=0.004, respectively).

Conclusions:

• LSCC dysplasia negatively impacts vestibulo-ocular reflex (VOR) function.
• The absence of a central bony island (CBI) in LSCC dysplasia is associated with more significant vestibular function impairment.