Mozart effect in epilepsy: Why is Mozart better than Haydn? Acoustic qualities-based analysis of stereoelectroencephalography.

BACKGROUND AND PURPOSE: We aimed to confirm the Mozart effect in epileptic patients using intracerebral electroencephalography recordings and the hypothesis that the reduction of epileptiform discharges (EDs) can be explained by the music's acoustic properties. METHODS: Eighteen epilepsy surgery candidates were implanted with depth electrodes in the temporal medial and lateral cortex. Patients listened to the first movement of Mozart's Sonata for Two Pianos K. 448 and to the first movement of Haydn's Symphony No. 94. Musical features from each composition with respect to rhythm, melody, and harmony were analyzed. RESULTS: Epileptiform discharges in intracerebral electroencephalography were reduced by Mozart's music. Listening to Haydn's music led to reduced EDs only in women; in men, the EDs increased. The acoustic analysis revealed that nondissonant music with a harmonic spectrum and decreasing tempo with significant high-frequency parts has a reducing effect on EDs in men. To reduce EDs in women, the music should additionally be gradually less dynamic in terms of loudness. Finally, we were able to demonstrate that these acoustic characteristics are more dominant in Mozart's music than in Haydn's music. CONCLUSIONS: We confirmed the reduction of intracerebral EDs while listening to classical music. An analysis of the musical features revealed that the acoustic characteristics of music are responsible for suppressing brain epileptic activity. Based on our study, we suggest studying the use of musical pieces with well-defined acoustic properties as an alternative noninvasive method to reduce epileptic activity in patients with epilepsy.

Non-invasive stimulation of the auditory feedback area for improved articulation in Parkinson's disease.

INTRODUCTION: Hypokinetic dysarthria (HD) is a common symptom of Parkinson's disease (PD) which does not respond well to PD treatments. We investigated acute effects of repetitive transcranial magnetic stimulation (rTMS) of the motor and auditory feedback area on HD in PD using acoustic analysis of speech. METHODS: We used 10 Hz and 1 Hz stimulation protocols and applied rTMS over the left orofacial primary motor area, the right superior temporal gyrus (STG), and over the vertex (a control stimulation site) in 16 PD patients with HD. A cross-over design was used. Stimulation sites and protocols were randomised across subjects and sessions. Acoustic analysis of a sentence reading task performed inside the MR scanner was used to evaluate rTMS-induced effects on motor speech. Acute fMRI changes due to rTMS were also analysed. RESULTS: The 1 Hz STG stimulation produced significant increases of the relative standard deviation of the 2nd formant (p = 0.019), i.e. an acoustic parameter describing the tongue and jaw movements. The effects were superior to the control site stimulation and were accompanied by increased resting state functional connectivity between the stimulated region and the right parahippocampal gyrus. The rTMS-induced acoustic changes were correlated with the reading task-related BOLD signal increases of the stimulated area (R = 0.654, p = 0.029). CONCLUSION: Our results demonstrate for the first time that low-frequency stimulation of the temporal auditory feedback area may improve articulation in PD and enhance functional connectivity between the STG and the cortical region involved in an overt speech control.

Quantitative Analysis of Relationship Between Hypokinetic Dysarthria and the Freezing of Gait in Parkinson's Disease.

Hypokinetic dysarthria (HD) and freezing of gait (FOG) are both axial symptoms that occur in patients with Parkinson's disease (PD). It is assumed they have some common pathophysiological mechanisms and therefore that speech disorders in PD can predict FOG deficits within the horizon of some years. The aim of this study is to employ a complex quantitative analysis of the phonation, articulation and prosody in PD patients in order to identify the relationship between HD and FOG, and establish a mathematical model that would predict FOG deficits using acoustic analysis at baseline. We enrolled 75 PD patients who were assessed by 6 clinical scales including the Freezing of Gait Questionnaire (FOG-Q). We subsequently extracted 19 acoustic measures quantifying speech disorders in the fields of phonation, articulation and prosody. To identify the relationship between HD and FOG, we performed a partial correlation analysis. Finally, based on the selected acoustic measures, we trained regression models to predict the change in FOG during a 2-year follow-up. We identified significant correlations between FOG-Q scores and the acoustic measures based on formant frequencies (quantifying the movement of the tongue and jaw) and speech rate. Using the regression models, we were able to predict a change in particular FOG-Q scores with an error of between 7.4 and 17.0 %. This study is suggesting that FOG in patients with PD is mainly linked to improper articulation, a disturbed speech rate and to intelligibility. We have also proved that the acoustic analysis of HD at the baseline can be used as a predictor of the FOG deficit during 2 years of follow-up. This knowledge enables researchers to introduce new cognitive systems that predict gait difficulties in PD patients.