Human Auditory and Adjacent Nonauditory Cerebral Cortices Are Hypermetabolic in Tinnitus as Measured by Functional Near-Infrared Spectroscopy (fNIRS)

Table 1

Mean oxy-hemoglobin (HbO) concentration and standard error (parentheses) from region (ROI) and nonregion of interest (non-ROI) during silence (interstimulus rest; ISR) and stimulation (750 Hz, 8000 Hz, broadband noise; BBN) between tinnitus and control. The unit of concentration is micromolar (M). Independent and pairwise -test analyses were conducted as shown to assess hemodynamic response differences during the various experimental conditions within and between groups for all conditions. Relative values to zero reflect a hemodynamic response deactivation (negative) versus activation (positive) in hemodynamic response (statistically significant as compared to ISR in controls; as compared to ISR in tinnitus; as compared to BBN in tinnitus; and between tinnitus and controls; ).

HbO	BBN	750 Hz	8000 Hz	ISR
ROI
Control	0.88 (0.83)	0.595 (0.53)	0.59 (0.61)	−1.31 (0.39)
Tinnitus	−1.59 (0.55)	0.49 (0.39)	0.20 (0.14)	0.14 (0.31)
Non-ROI
Control	−0.90 (1.27)	−1.96 (0.63)	0.39 (0.75)	−0.78 (0.26)
Tinnitus	−1.97 (0.59)	−0.93 (0.52)	−0.47 (0.32)	0.89 (0.30)