Models and Analysis of Vocal Emissions for Biomedical Applications

The MAVEBA Workshop proceedings, held on a biannual basis, collect the scientific papers presented both as oral and poster contributions, during the conference. The main subjects are: development of theoretical and mechanical models as an aid to the study of main phonatory dysfunctions, as well as the biomedical engineering methods for the analysis of voice signals and images, as a support to clinical diagnosis and classification of vocal pathologies

Models and Analysis of Vocal Emissions for Biomedical Applications

The International Workshop on Models and Analysis of Vocal Emissions for Biomedical Applications (MAVEBA) came into being in 1999 from the particularly felt need of sharing know-how, objectives and results between areas that until then seemed quite distinct such as bioengineering, medicine and singing. MAVEBA deals with all aspects concerning the study of the human voice with applications ranging from the neonate to the adult and elderly. Over the years the initial issues have grown and spread also in other aspects of research such as occupational voice disorders, neurology, rehabilitation, image and video analysis. MAVEBA takes place every two years always in Firenze, Italy. This edition celebrates twenty years of uninterrupted and succesfully research in the field of voice analysis

Using Multimodal MRI Techniques to Derive a Biomarker for Tracking the Pathological Changes Occurring at Different Stages of Cognitive Decline in Parkinson's Disease in a Cross-Sectional Study Design

Cognitive impairment is common in Parkinson's disease (PD) and can range from mild cognitive impairment (PD-MCI) to dementia (PDD). The aim of this study was to derive a multi-modal MRI-based biomarker for the reliable discrimination of PD patients at different stages of cognitive decline and to identify pathologic patterns related with dementia risk. The resting-state functional MRI (rs-fMRI), diffusion tensor imaging (DTI), Arterial Spin Labeling and MR spectroscopic imaging data of 60 PD patients (PD-N, PD-MCI, PDD) were collected. The rs-fMRI data revealed a combination of resting-state networks with significant discriminative power based on the expression scores of the resting-state networks. In combination with the DTI data we obtained a successful model for the discrimination of PDD patients and were able to identify progressive pathological changes that can be used as biomarker for PDD and could be established as clinical diagnostic tool for PD patients with high dementia risk

Oscillatory activity in the basal ganglia - is it relevant to movement disorders therapy?

Chronic high frequency stimulation of the basal ganglia can be a highly effective intervention for movement disorders in patients. In the past decade, therapeutic benefits have been seen with stimulation of the subthalamic nucleus and globus pallidus interna for Parkinson's disease (PD) and dystonia, respectively. These procedures have allowed direct recording of basal ganglia activity and have suggested that abnormal synchronisation of neurons in these nuclei may contribute to motor impairment. This thesis explores the possible correlation between synchronised activity in the basal ganglia, as evidenced by oscillations in local field potentials, and movement disorders. In Chapter 3, we demonstrate the correlation between synchronization at frequencies under 10 Hz in the globus pallidus interna and dystonic EMG. This low frequency activity is shown to be locked to neuronal activity within GPi in patients with dystonia (Chapter 4). Deep brain stimulation is thought to suppress spontaneous pathological activity in the basal ganglia. Equally, however, it must also suppress any residual physiological activity in these nuclei. In Chapter 5, we demonstrate that the basal ganglia are involved in the processing of simple limb movements in the human, by separating the effects of deep brain stimulation on pathological and physiological activities based on baseline task performance. An impairment of motor performance was seen during high frequency stimulation in those patients with the best task performance at baseline. This deleterious effect, however, should be distinguished from the effect of direct stimulation at 20 Hz in Parkinson's disease. Oscillatory activity at around 20 Hz is thought to be a core feature in Parkinson's disease. In Chapter 6, we demonstrate that the excessive synchronization imposed by stimulation of the subthalamic nucleus at 20 Hz slows movement, in those patients with the best task performance at baseline. This supports the notion that synchronization around 20 Hz may be causally linked to bradykinesia. Last, the therapeutic effectiveness of DBS therapy for patients with PD partially relies on the accurate localisation of the motor region of the subthalamic nucleus. In Chapter 7, we propose an alternative method for the localization of this region using the spontaneous pathological 20 Hz activity to be found in this nucleus. The findings of these studies provide evidence that basal ganglia oscillatory activities of differing frequencies contribute to movement disorders

What makes us tic?

Published work 1971-2006, comprising 4 books, various articles, 2 review discussions on a videorecording, and supporting documents

Social Aspects of Communication in Parkinson's Disease

Parkinson’s disease is a degenerative neurological condition which affects motor control, in almost all cases involving speech, and is frequently of many years duration. Much is known about speech production but less of the psychosocial consequences of the speech impairment (dysarthria). Accounts of people with dysarthria have shown that its impact on quality of social participation can be varied and profound. However, level of participation has not been investigated. Reduction in social activity and social networks has been found following onset of other neurogenic communication disorders. In Parkinson’s disease there is some evidence of social activity reduction but this has not been studied in relation to severity of dysarthria. Social anxiety has been found to be raised in speakers with other speech production impairments and this may be a contributor to reduction in social engagement. Investigation of social variables is of importance in understanding relationships within a biopsychosocial model of health which underpins intervention for therapies for communication disorders. Aims The study aimed to investigate the impact of dysarthria on social participation and whether presence of dysarthria in Parkinson’s disease (PD) resulted in changes to social anxiety, social networks and social activity. It further sought to investigate whether severity of dysarthria resulted in changes to the same variables. Method A group of 43 mild-moderately dysarthric speakers with PD were recruited. Exclusion criteria were applied to control for cognitive impairment, depression, apathy, movement disability and co-occurring neurological and communication impairment. A group of 30 non-neurologically impaired participants were recruited matched for age, sex, socioeconomic status and educational attainment. Participants with PD were further grouped using measures of sentence intelligibility and motor speech impairment into higher and lower functioning groups. All participants completed a social anxiety questionnaire, a social activity checklist and detailed their social network. Group data were compared to address the research questions. Semi-structured interviews were carried out with all participants to explore change to social life and perceptions of causes of change. Results Participants reported a range of changes to interaction and social engagement arising from speech and other impairments and also from intra and interpersonal contextual factors. Quantitative data showed that presence of dysarthria was associated with social anxiety and avoidance but not changes to social activity level or social network size. Greater severity of dysarthria was associated with deterioration in social activities and social network. There was wide individual variation on these variables. Outcomes Impact of dysarthria may be significant and unrelated to severity of impairment and satisfaction with level of activity is low in dysarthric speakers. Mild - moderately dysarthric speakers with PD may experience social anxiety in particular types of social situation. Moderately dysarthric speakers may experience loss of social capital in terms of quantitative changes in social networks and social activities. Motor speech impairment was a better predictor of social functioning than intelligibility in this sample. It is possible that a threshold for change lies at a more severe level of speech involvement. How speakers with PD perceive and experience their social interactions is discussed and limitations to the research are considered. The implications of the findings are discussed in relation to the ICF framework and the concept of social capita