Click-evoked and speech-evoked auditory brainstem responses from individuals with multiple sclerosis

Area of Science:

• Neuroscience
• Audiology
• Clinical Neurology

Background:

• Multiple sclerosis (MS) is a demyelinating disease affecting the central nervous system.
• Auditory pathway dysfunction is a common, yet often subclinical, manifestation of MS.
• Conventional auditory brainstem response (ABR) using click stimuli has limitations in detecting subtle auditory pathway changes in MS.

Purpose of the Study:

• To compare the sensitivity of speech-evoked ABR with click-evoked ABR in detecting auditory pathway abnormalities in MS patients.
• To investigate the impact of noise on speech-evoked ABR in individuals with MS.

Main Methods:

• A cohort of 11 MS patients and 9 age- and gender-matched controls underwent both click-evoked and speech-evoked ABR testing.
• Stimuli included rarefaction clicks and a synthetic /da/ syllable presented at various rates and intensities.
• Speech-evoked ABRs were recorded in quiet and noise conditions using a single-channel montage.

Main Results:

• Click-evoked ABR showed absent responses more frequently at high rates in controls than in MS patients.
• Speech-evoked ABR measures, including peak amplitudes, wave E latency, and VA complex slope, effectively differentiated MS patients from controls.
• Significant group differences were observed in the correlation of speech-evoked ABR responses between quiet and noise conditions.

Conclusions:

• Speech-evoked ABR is as sensitive, or more sensitive, than conventional click-evoked ABR for detecting MS-related auditory pathway changes.
• Analysis of speech-evoked ABR in quiet versus noise conditions highlights impaired neural synchrony in MS.
• Speech-evoked ABR offers a valuable tool for assessing auditory pathway integrity in MS, potentially revealing deficits not evident with traditional methods.