Auditory pathways: spatial distribution in cortical brain in normal and tinnitus patients studied through loreta
Abstract
Advances in basic research in neurosciences and the introduction of new non-invasive techniques, that make possible the detection of weak signals of the brain, have revolutionized diagnosis and treatment. The most often used methods for functional imaging of the human brain are positron emission tomography (PET) and functional magnetic resonance imaging (FMRI).
More recently, a growing number of studies have been published that make use of functional imaging methods based on the electroencephalogram (EEG) and the magnetoencephalogram (MEG).
We use in our laboratory the EEG register in 21 derivation channels. The use of a specialized software (LORETA) makes possible obtaining functional imaging of the brain in 2D and 3D. Studies have been carried out through – Low Resolution Brain Electric Tomography – LORETA – on the spatial distribution of Cortical Evoked Response Audiometry (CERA) in normal patients and in 25 patients with tinnitus. Results have been compared vs. 40 patients who have not shown tinnitus symptoms.
The study of temporal distribution through the brain electric tomography represents the opening of a new field in tinnitus treatment.
The existence of frontalization in all these patients and the involvement of the limbic area have been extensively demonstrated in tinnitus.