Daugelis neurodegeneracinių ligų klinikinių žymenų yra nespecifiniai ir nustatomi tik progresavus ligai. Neurodegeneracinio parkinsonizmo diagnostika remiasi klinikiniais kriterijais, tačiau idiopatinės Parkinsono ligos (PL), kuri yra pati dažniausia neurodegeneracinio parkinsonizmo priežastis, klinikiniai požymiai dažnai pasireiškia ir esant kitiems parkinsonizmo sindromams. Patikimas, neinvazinis, nebrangus ir saugus diagnostinis testas PL, galbūt ir demencijų diagnostikai bei diferencinei diagnostikai yra aktualus dėl kelių pagrindinių priežasčių: skirtingų parkinsonizmo sindromų medikamentinis gydymas ir ligos prognozė labai skiriasi; tiksli diagnozė svarbi imantis neatidėliotinų priemonių užkertant kelią kai kurioms sindromams būdingoms gyvybei grėsmingoms komplikacijoms; PL ankstyvoji diagnostika ikiklinikinėje stadijoje leistų anksčiau parinkti ir pradėti patogenezinį gydymą; atsiradus efektyvios neuroprotekcijos galimybėms, atsirastų ir tam tikro amžiaus populiacijos atrankinės patikros įrankio poreikis. Disertacinio darbo tikslas buvo nustatyti transkranijinės sonografijos vertę neurodegeneracinių ekstrapiramidinės nervų sistemos ligų diagnostikai, diferencinei diagnostikai ir atrankinei patikrai. Užsienio mokslininko dalyvavimas doktorantūros procese finansuojamas Lietuvos mokslo tarybos (konkurso paraiškos Nr. VIZ-DOK-124, doktorantūros tarybos narė doc. dr. Pille Taba). / The most symptoms of neurodegenerative disorders are non-specific and come to clinical attention only when the disease has progressed. The diagnostics of neurodegenerative parkinsonism is based on clinical criteria. However, the symptoms of idiopathic Parkinson‘s disease (PD), which is the most common cause of neurodegenerative parkinsonism, are often observed in patients with other parkinsonian syndromes. A reliable, non-invasive, safe and affordable test for the diagnosis and differential diagnosis of PD and, perhaps, dementia is relevant for multiple reasons: the disease prognosis and treatment of parkinsonian syndromes differs greatly and an unbiased disease marker would facilitate the development of neuroprotective drugs; the exact diagnosis is crucial in order to take urgent measures to avoid life-threatening complications; early diagnosis of PD would enable pathogenetic treatment; with the arrival of neuroprotective options, the need for selective screening of population according to certain age and other risk factors would arise. The aim of the doctoral study was to investigate the value of transcranial sonography for the diagnosis, differential diagnosis and screening of neurodegenerative extrapyramidal disorders. Participation of the Scientist from foreign institution in the Process of Doctoral Studies is financed by the Research Council of Lithuania (Tender-based financing application No VIZ-DOK-124, the Defence Council Member Assoc. Prof. Dr. Pille Taba).

The role of metal accumulation in the pathophysiology of neurodegenerative diseases has been a hot topic in recent years due to the possibility of its treatment by chelating agents. Although the mechanisms of neurodegeneration are well known, the role of metal accumulation is still unclear. The main limitation are unsatisfactory methods for in vivo metal imaging; the most widely used technique is magnetic resonance imaging (MRI). Our aim was to assess the possibility of using transcranial sonography (TCS) in differential diagnosis of neurodegenerative diseases and to further explore the underlying factors of echogenicity. In the first study, using TCS fusion with MRI, we focused on location verification of the commonly assessed structures (substantia nigra and nucleus lentiformis) and exclusion of possible focal structural changes affecting the echogenicity in WD and PD patients. Moreover, obtained MRI were used for semi-quantitative comparison with TCS images. Although TCS has been confirmed to be highly beneficial in differential diagnosis of Wilson's disease and it should be recommended as a screening method for extrapyramidal patients with atypical course of the disease, the direct relationship between TCS and metal deposits could not be proven. The obtained results from the ultrasound fusion...