Cortical tinnitus evaluation using functional near-infrared spectroscopy.

Area of Science:

• Neuroscience
• Medical Imaging
• Auditory Science

Background:

• Tinnitus, a prevalent auditory disorder, impacts quality of life.
• Functional near-infrared spectroscopy (fNIRS) offers a non-invasive method to assess cortical hemodynamic responses.
• Understanding tinnitus-related neural activity is crucial for developing effective treatments.

Purpose of the Study:

• To compare oxy-hemoglobin and deoxy-hemoglobin concentration changes in individuals with and without tinnitus.
• To investigate brain activity using fNIRS during auditory stimulation in tinnitus patients and controls.

Main Methods:

• A cohort of 23 tinnitus patients and 23 controls underwent an auditory task.
• fNIRS with 20 channels was used to monitor activity over frontal, temporal, and parietal cortices.
• A block-paradigm design involved auditory stimuli interspersed with silence periods.

Main Results:

• Significant differences in hemodynamic responses were observed based on sound type, brain region, and channel.
• Tinnitus Frequency sound decreased HbO levels, while white noise and 1KHz increased them.
• No significant differences in overall hemodynamic responses were found between the tinnitus and control groups.

Conclusions:

• Sound type and brain region modulated hemodynamic responses, but not between groups.
• Tinnitus loudness, annoyance, and severity showed a weak correlation with observed hemodynamic changes.
• fNIRS did not reveal distinct cortical hemodynamic differences between individuals with and without tinnitus in this study.