Clinical evaluation of the monothermal caloric test

Area of Science:

• Otolaryngology
• Neurology
• Vestibular System Assessment

Background:

• The Torok Monothermal Caloric Test (TMCT) was proposed to differentiate labyrinthine from retrolabyrinthine lesions.
• It compares nystagmus responses to strong and weak irrigations of room-temperature water.

Purpose of the Study:

• To evaluate the clinical utility of the TMCT in distinguishing between labyrinthine and retrolabyrinthine pathologies.
• To verify the test's ability to lateralize lesions and assess its sensitivity and selectivity.

Main Methods:

• The TMCT was performed on patients with confirmed labyrinthine (N=9) and retrolabyrinthine (N=25) lesions.
• Patients with dysequilibrium and nonlocalizing findings (N=10) were also included.
• Test results were analyzed for recruitment and decruitment patterns.

Main Results:

• Decruitment was observed in 56% of retrolabyrinthine cases, but only 42% on the lesion side.
• Decruitment occurred in 47% of patients without retrolabyrinthine lesions, including 63% with Meniere's disease.
• Recruitment was never detected on the side of a labyrinthine lesion.

Conclusions:

• The TMCT demonstrates moderate sensitivity for detecting retrolabyrinthine lesions.
• However, the test exhibits poor lateralization accuracy and lacks high selectivity.
• The TMCT was found to be insensitive for diagnosing labyrinthine diseases.