The research group of Dr. Rusz deals with theoretical issues and practical applications in the field of neurology, phoniatrics, and speech therapy, and especially analysis, modeling and interpretation of speech pathologies. The results of the research are part of joint projects with medical institutions around the world, where they lead to deeper knowledge and are used in the diagnosis and evaluation of treatment efficacy. Current topics include, for example, speech analysis for early diagnosis of Parkinson's disease, differential diagnosis of neurological diseases based on speech, or evaluation of the effects of drugs and surgery on speech quality.

Speech is an important indicator of motor function and coordination and is extremely sensitive to the damage of the central nervous system. Parkinson's disease is a chronic neurodegenerative disorder directly related to the loss of dopamine-generating cells in the part of the brain called Substantia nigra with a prevalence of 1-2% of people over the age of 60. The first motor symptoms, i.e. tremor, rigidity and slowness of movements, occur after the death of 60-70% of dopaminergic neurons. From this point of view, early diagnosis is crucial for improving the quality of a patient's life. Changes in speech, which can be characterized by monotony, imprecise articulation or inability to keep stable rhythm, can precede the development of motor symptoms by up to 10 years before the diagnosis. The research of our group is mainly focused on the development of new technologies based on digital signal processing methods for automatic evaluation of the severity of speech disorders. These technologies represent an accurate, objective, non-invasive and inexpensive method that can serve as a useful tool for the early diagnosis of CNS diseases. We further focused on the research of a rare hereditary disorder called Huntington's disease. This disorder is a suitable experimental model as it allows us to detect the presence of the affected gene in person and thus provide the opportunity to observe the development of the disease from pre-clinical stages to the onset of the first disease-related symptoms.

Speech disorders called dysarthria may substantially differ with respect to various neurological diseases. Type of dysarthria is closely related to the position of the lesion in the brain, and therefore speech can be a valuable marker for neurological localization and may be diagnostically helpful in a number of neurological disorders. For example, the speech of patients with Parkinson's disease typically displays monotone intonation whereas patients with stroke are likely to exhibit contradictory speech pattern of excess pitch variation. The research of our group is mainly focused on the development of new technologies based on digital signal processing methods for the identification of deviant speech dimensions such as monopitch, harshness, rapid speech, imprecise articulation and many others. We aimed at differentiation between the speech of atypical parkinsonian syndromes such as progressive supranuclear palsy or multiple system atrophy. In clinical practice, the majority of patients with atypical parkinsonian syndromes develop clinical features that overlap those of Parkinson's disease, and the correct diagnosis may only become clear as the disease progresses. Nevertheless, accurate and early diagnosis is essential for making decision regarding management of treatment, assessing prognosis, but also for understanding pathophysiology of the underlying disease and developing possible new treatment strategies.

Although for most of neurodegenerative diseases, there is currently no available treatment that could stop or even slow the death of the brain cells, modern medicine offers many approaches that can alleviate the various symptoms of the diseases. These approaches include a variety of drugs, speech and rehabilitative therapy, or even surgical intervention. It is possible to effectively relieve the main motor symptoms of Parkinson's disease, i.e. tremor, rigidity and slowness of movements, using the administration of the drug known as levodopa, which causes stabilization of dopamine in the brain. Most patients show a positive response to treatment allowing them to return to normal life. Another treatment option covers deep brain stimulation, a surgical intervention, whose principle is electrical stimulation of the affected part of the brain. Our research group participates in a project that focused on the assessment of the effect of stimulation parameters reconfiguration, including frequency and amplitude, on walking and speech. We further investigate the effects of levodopa on speech in Parkinson's disease and antipsychotics in Huntington's disease, as well as physiotherapy effectiveness concerning the improvement of trunk stability and related speech alterations in patients with spinocerebellar ataxia. In the future, we would also like to aim at the assessment of speech therapy, since the acoustic analysis can be considered as a valuable tool for motivation and feedback during speech therapy.

Research group pages