Bilaterally positive head-impulse tests can differentiate AICA infarction from labyrinthitis

Area of Science:

• Neurology
• Ophthalmology
• Otolaryngology

Background:

• Video head-impulse tests (video-HITs) are crucial for diagnosing vestibular disorders.
• Anterior inferior cerebellar artery (AICA) infarction can present with acute audiovestibular syndrome (AAVS), mimicking peripheral vestibular dysfunction.
• The diagnostic utility of video-HITs in differentiating AICA infarction from labyrinthitis, a common cause of AAVS, requires further investigation.

Purpose of the Study:

• To evaluate the diagnostic value of video-HIT patterns in patients with AAVS.
• To compare video-HIT findings between AICA infarction and labyrinthitis.
• To identify video-HIT characteristics associated with AICA infarction.

Main Methods:

• Retrospective review of medical records for patients with new-onset AAVS.
• Inclusion of patients diagnosed with AICA infarction or labyrinthitis.
• Categorization of video-HIT patterns: ipsilaterally positive, contralaterally positive, bilaterally normal, and bilaterally positive.

Main Results:

• Of 28 AICA infarction patients and 51 labyrinthitis patients, 54% of AICA infarction cases presented with isolated AAVS.
• Bilaterally positive video-HITs were observed in 13 AICA infarction patients, contrasting with 12% of labyrinthitis patients.
• Logistic regression indicated bilaterally positive HITs and multiple vascular risk factors were significantly associated with AICA infarction (p=0.004 and p=0.043, respectively).

Conclusions:

• Bilaterally positive video-HITs are a potential indicator of AICA infarction in AAVS patients.
• The presence of multiple vascular risk factors further supports the diagnosis of AICA infarction when video-HITs are bilaterally positive.
• Video-HITs can aid in differentiating AICA infarction from labyrinthitis in the context of AAVS.