Time-Frequency Analysis for gustatory Event Related Potentials can be used as a diagnostic tool in taste disorders
Tue-P1-020
Presented by: Mariano Mastinu
Introduction: The key to a correct diagnosis and an adequate treatment of taste disorders (dysgeusia) is a detailed assessment, which is a challenge in everyday clinical practice. In adddition to psychophysical tests, EEG-derived gustatory Event Related Potentials (gERP) are used as an electrophysiological approach to taste function. However, the responses identified using conventional time-domain averaging showed low signal-to-noise ratio.
Methods: In this study, 44 patients with dysgeusia and 59 healthy participants were examined using the neuronal processing of taste stimuli analyzed with Time-Frequency Analysis (TFA). Participants underwent a comprehensive clinical examination of taste and olfactory function. In addition, gERPs were recorded from 128 active electrodes in response to stimulation with two different concentrations of salty solutions, which were applied with a high precision gustometer.
Results: Patients showed significantly lower scores for gustatory chemical and electrical stimuli (p ≤ 0.008), but their performance in suprathreshold taste testing did not differ from controls. For gERPs, higher amplitudes of peak N1, and lower amplitude of peak P2, were observed in patients recorded in the electrode Pz compared to controls (p ≤ 0.024). High concentrated stimulus evoked larger P2 amplitudes at Pz compared to low concentrated stimulus, but only in controls (p = 0.009). Moreover, TFA showed that stimulations led to a stronger power in controls than in patients in the low frequencies (0.1-2 Hz), which was correlated to psychophysical taste scores (p ≤ 0.043), and a significant long-lasting desynchronization of alpha-band (8–12 Hz), which was delayed in time.
Conclusions: These changes might indicate a compensatory neuronal activation in patients due to the taste impairment. Overall, the results of this study suggest that TFA coupled with gERP can be a useful tool for the diagnosis of dysgeusia.
Methods: In this study, 44 patients with dysgeusia and 59 healthy participants were examined using the neuronal processing of taste stimuli analyzed with Time-Frequency Analysis (TFA). Participants underwent a comprehensive clinical examination of taste and olfactory function. In addition, gERPs were recorded from 128 active electrodes in response to stimulation with two different concentrations of salty solutions, which were applied with a high precision gustometer.
Results: Patients showed significantly lower scores for gustatory chemical and electrical stimuli (p ≤ 0.008), but their performance in suprathreshold taste testing did not differ from controls. For gERPs, higher amplitudes of peak N1, and lower amplitude of peak P2, were observed in patients recorded in the electrode Pz compared to controls (p ≤ 0.024). High concentrated stimulus evoked larger P2 amplitudes at Pz compared to low concentrated stimulus, but only in controls (p = 0.009). Moreover, TFA showed that stimulations led to a stronger power in controls than in patients in the low frequencies (0.1-2 Hz), which was correlated to psychophysical taste scores (p ≤ 0.043), and a significant long-lasting desynchronization of alpha-band (8–12 Hz), which was delayed in time.
Conclusions: These changes might indicate a compensatory neuronal activation in patients due to the taste impairment. Overall, the results of this study suggest that TFA coupled with gERP can be a useful tool for the diagnosis of dysgeusia.