The topic of the master’s thesis is early discovering of cognitive and other clinical characteristics in patients with REM sleep behavior disorder (RBD), who are at high risk of the development of any of alpha-synucleinopathy. These are neurodegenerative brain diseases, where misfolded protein alpha-synuclein aggregation occurs in brain excessively. The most common alpha-synucleinopathy is Parkinson disease (PD).
The process of neurodegeneration in brains of persons with alpha-synucleinopathy, among which there is also multiple systemic atrophy (MSA) and Lewy body dementia, occurs many years before the emergence of the clinical signs. Therefore, the persons with prodromal signs of neurodegenerative diseases are the most appropriate population for the research of potential biological markers, which could predict the development of disease, and also for the research of potential neuroprotective medicaments. We already know some biological markers of prodromal phases of diseases: RBD, smell disorder, and the hyperechogenicity of the substantia nigra in the transcranial Doppler investigation. None of these, however, was a good marker of disease progression and cannot predict when the disease is going to emerge with the clinical signs also. Longitudinal studies of monitoring the patients with the RBD represent the basis for improvement of our understanding of the basic neurobiological mechanisms, the role of biological equalizers, i.e. biomarkers, and factors which influence the progression of the disease.
In our pilot cross-sectional study, which will be the basis for the prospective study we especially focused on the disorder of cognitive functions. We included six patients with polysomnographically confirmed RBD in the study examined them clinically and neurologically and performed structural and functional brain imaging (magnetic resonance tomography, scintigraphy of dopamine transporter, imaging of brain metabolism using fluorodeoxyglucose, and positron emission tomography), examination of alpha-synuclein in liquor, and testing cognitive functions with screening scales and by means of the computer version of the cognitive control task, are already present in subjects with polysomnographically confirmed RBD. We used the experimental method of testing cognitive functions by using the paradigm of flexible cognitive control.
We discovered that the persons with the isolated RBD have also other signs which are known prodromes of the PB: smell disorder, mood disorder, and altered brain activity, in spite of still preserved dopaminergic integrity (proved by a normal report of scintigraphy of dopamine transporter). The patients with the RBD are cognitively decelerated in comparison A Qasyto the healthy subjects. This cognitive disorder could become a promising biomarker of the progression of the disease. This will be researched in the prospective part of the study.