Cochlear Microphonic and Summating Potential Responses from Click-Evoked Auditory Brain Stem Responses in High-Risk...

Area of Science:

• Audiology
• Neonatal Medicine
• Neuroscience

Background:

• Infants in neonatal intensive care units (NICUs) are at high risk for auditory neuropathy (AN) due to hyperbilirubinemia.
• Assessing sensory and neural status in these infants requires examination of cochlear and neural potentials.

Observation:

• This prospective study compared auditory brain stem response (ABR) and electrocochleography (ECochG) parameters in NICU infants and well-baby nursery (WBN) infants who passed newborn hearing screening.
• The study analyzed cochlear microphonic (CM), summating potential (SP), and ABR Waves I, III, and V latencies and amplitudes.

Findings:

• No significant differences in ABR waveforms, CM, or SP amplitude and latency were found between the NICU and WBN groups.
• The majority of NICU infants had hyperbilirubinemia, but their auditory evoked responses at one-month corrected age showed no significant effects.

Implications:

• Standard click-evoked ABR and ECochG parameters are useful for assessing auditory function in both well and NICU infants.
• Combining ECochG and ABR with otoacoustic emissions and acoustic reflex tests may offer a more comprehensive evaluation of AN and sensorineural hearing loss (SNHL) risks in infants.