Cochlear implant induced changes in cortical networks associated with tinnitus severity

Area of Science:

• Neuroscience
• Audiology
• Biomedical Engineering

Background:

• Tinnitus is the perception of sound without external stimuli, often debilitating.
• Cochlear implant (CI) use can modulate tinnitus, but underlying neural mechanisms are unclear.
• Understanding cortical network changes associated with CI use is crucial for tinnitus management.

Purpose of the Study:

• Investigate tinnitus-related cortical network changes in CI users.
• Correlate subjective tinnitus perception changes with objective neural network alterations.
• Determine if CI use impacts functional connectivity and tinnitus symptoms.

Main Methods:

• Functional near-infrared spectroscopy (fNIRS) recorded cortical activity in 14 CI users with tinnitus.
• Cortical activity was measured with the cochlear implant (CI) off and on.
• Functional connectivity networks were analyzed using node strength and diversity coefficient.

Main Results:

• Reduced tinnitus loudness correlated with changes in node strength (occipital channels).
• Tinnitus loudness and annoyance changes correlated with diversity coefficient (all channels).
• More distributed brain connectivity with CI on was linked to decreased tinnitus loudness and annoyance.

Conclusions:

• CI use alters cortical network organization, impacting tinnitus perception.
• Changes in functional connectivity, specifically node strength and diversity, are associated with tinnitus modulation.
• Findings suggest CI-induced neural plasticity could inform tinnitus treatment strategies.