Brain activation in patients with idiopathic hyperacusis.

The neural network associated with idiopathic hyperacusis is still not well known. We studied the brain activation of 3 middle-aged patients with mild to moderate hyperacusis by functional magnetic resonance imaging while they were listening to white noise binaurally. In addition to the temporal lobes, in all patients, sound elicited activation in the frontal lobes (superior, middle, or inferior frontal gyri) and occipital lobes (precuneus, cuneus, superior occipital gyrus, lingual gyrus, or fusiform gyrus). The parahippocampus was activated in 2 of 3 patients. Furthermore, the precentral and postcentral gyri, superior and inferior parietal lobules, thalamus, midbrain, claustrum, insula, posterior cingulated gyrus, and orbital and rectal gyrus were also activated in one patient. The neural network associated with idiopathic hyperacusis might be associated with the frontal lobes and parahippocampus.