Auditory brainstem response latencies in patients with tinnitus

Area of Science:

• Neuroscience
• Audiology
• Otolaryngology

Background:

• Tinnitus is a common auditory perception.
• Its underlying pathophysiology, especially in relation to hearing loss, requires further investigation.
• Brainstem response audiometry is a diagnostic tool for auditory pathway function.

Purpose of the Study:

• To investigate brainstem auditory pathway function in patients experiencing tinnitus.
• To identify specific electrophysiological abnormalities associated with tinnitus.
• To correlate these abnormalities with the degree of hearing loss.

Main Methods:

• Brainstem response audiometry was performed on two groups of tinnitus patients: one with normal/slight hearing loss (n=56) and another with moderate/pronounced sensorineural hearing loss (n=57).
• Patients were compared to 220 age- and gender-matched controls with similar hearing loss profiles.
• Analysis focused on wave latencies and interpeak latencies (IPLs).

Main Results:

• Two distinct patterns of abnormalities were identified in tinnitus patients.
• Pattern 1: Prolongation of wave I, III, and V latencies, suggesting peripheral auditory system lesions.
• Pattern 2: Lengthening of the III-V interpeak latency, indicating brainstem dysfunction. Both patterns were more prevalent in tinnitus patients with normal or slight hearing loss.

Conclusions:

• Tinnitus is associated with electrophysiological abnormalities in the auditory pathway, including peripheral and central (brainstem) components.
• These abnormalities, particularly peripheral lesions and brainstem dysfunction, are frequently observed in tinnitus patients even with minimal hearing loss.
• Brainstem response audiometry can reveal subclinical auditory pathway dysfunction in tinnitus patients.