Selective Bilateral Posterior Canal Dysfunction: A Case Series Investigation into the Clinical Trends and Associative...

Area of Science:

• Otolaryngology
• Neurology
• Vestibular Science

Background:

• The video head impulse test (vHIT) assesses high-frequency vestibulo-ocular reflex function across all six semicircular canals.
• Isolated semicircular canal dysfunction is linked to various peripheral and central vestibular disorders.
• Bilateral posterior semicircular canal dysfunction is observed clinically but infrequently documented in literature.

Purpose of the Study:

• To investigate the clinical characteristics of bilateral posterior semicircular canal dysfunction.
• To explore associated factors including hearing loss, advanced age, and nystagmus patterns.

Main Methods:

• A case series involving three patients aged 67-74 years.
• Analysis of vestibular and balance history, medical history, and vHIT results.
• Correlation of clinical findings with semicircular canal function.

Main Results:

• All patients exhibited reduced posterior semicircular canal function on vHIT.
• Two patients displayed down-beating nystagmus.
• Two patients reported subjective hearing loss; one had presbycusis.

Conclusions:

• Selective bilateral posterior canal dysfunction, coupled with advanced age, presbycusis, and down-beating nystagmus, may suggest vestibulocochlear degenerative processes.
• Distinguishing from central disorders, technical, and patient-related factors poses diagnostic challenges.