Ongoing Projects

Determination of Multimodality Magnetic Resonance Imaging Based Biomarkers for Mild Cognitive Impairment in Parkinson Disease
Original Title:    Parkinson Hastalığı Hafif Kognitif Bozukluğu İçin Multimodal Manyetik Rezonans Görüntüleme Temelli Biyoişaretleyicilerin Belirlenmesi
Principal Investigator:    Esin Öztürk Işık, Institude of Biomedical Engineering, Bogazici University
Partners:    Boğaziçi University, Istanbul University
Researchers:    
Grant:    2015 TUBITAK 1001, # 115S219
Project Summary:    The aim of this project is to identify biomarkers that would indicate the presence of mild cognitive impairment (MCI) and the probability of its evolution into dementia using machine learning algorithms, by evaluating the findings from multimodal MR imaging of patients diagnosed with PD-MCI, cognitively intact PD and healthy controls.
Integration of rs-fMRI, dMRI, ASL and MRSI data collected from patients with Parkinson’s disease (PD) and healty controls.

Another purpose of this project is to determine neuroimaging parameters which are correlated with different genotypes of COMT (catechol-O-methyltransferase) and MAPT (microtubule-associates protein tau), genes known to be assosciated with cognitive decline in PD.

Implicit Memory In Patients With Spinocerebellar Ataxia And Its Structural And Functional Connectivity Correlations
Original Title:    Spinoserebellar ataksili hastalarda örtük bellek süreçleri ile yapısal ve fonksiyonel konnektivite korelasyonları
Principal Investigator:    Prof. Dr. İbrahim Hakan Gürvit, Department of Neurology, Istanbul Faculty of Medicine, Istanbul University
Partners:    Istanbul University
Researchers:     
Prof. Dr. Haşmet Ayhan Hanağası,

Assist. Prof. Dr. Başar Bilgiç,

Assist. Prof. Dr. Aslı Demirtaş Tatlıdede,

Prof. Dr. Tamer Demiralp (Adviser)

Grant:    TUBITAK 1001, # 115S437
Project Summary:     
The aims of this project are (1) to investigate the intrinsic connectivity network (ICN) for implicit associative learning, and (2) to reveal how it is altered by cerebellar degeneration in spinocerebellar ataxia. We suggest that contribution of cerebellum to implicit associative learning is mediated through cerebello-striatal connectivity. Moreover, functional and structural connectivity between cerebellum and cerebral cortex with subcortical structures will be investigated.

Traditionally, cerebellum and basal ganglia were associated with only motor functions and considered as they were involved in both anotomically and functionally distinct systems. Accordingly, interactions between them could be only at the cortical level. On the other hand, accumulating information from neurosurgery, electroneurophysiology, neuropsychology and neuroanatomy studies reveal that cerebellum densely interacts with basal ganglia, and they each contribute cognitive processes. In addition to this, cerebellum and basal ganglia were separately associated with various forms of implicit learning. However, while the studies on SCA are mostly related with implicit motor learning, non-motor implicit associative learning has been neglected and its neural basis remained unlighted. Functional magnetic resonance imaging (fMRI) on implicit associative learning showed that hippocampal involvement in early stage of learning becoming increasingly dependent on basal ganglia with practice. Cerebellar involvement in implicit associative learning was also reported. Apart from the task-based studies, there is no study on resting state fMRI on SCA. While various ICNs have been defined such as visual, auditory, sensorimotor, language, sailence, episodic memory-self reflection network, any ICN for implicit associative learning has been suggested until now. This is the first time implicit associative learning has been described with subcortical connections and a corresponding ICN has been suggested. This will be the first study investigated non-motor implicit associative learning in SCA, and its correlations with structural and functional connectivity.

The project will be carried out with 20 patients with SCA, age, gender, education level-matched 20 healthy controls. All participants will complete a neuropsychological battery that assessed attention, memory, language, visuospatial functions, and executive functions and they will undergo diffusion tensor imaging and functional magnetic resonance imaging. Ataxia scores in patients will be evaluated with International Co-operative Ataxia Rating Scale. The ICN for implicit associative learning will be produced and how this ICN is altered by cerebellar degeneration will be shown.

We expect that outputs of this project will mediate the identification of ICNs for implicit learning, especially for implicit associative learning. If we can reveal the neural correspondence of implicit associative learning; it leads to clinical developments such as improving intact implicit memory abilities, taking advantage of this plasticity and planning rehabilitation (e.g. with repetitive transcranial magnetic stimulation [rTMS]) for various neurodegenerative disorders (e.g. Alzheimer disease) and/or seconder demential disorders (e.g. Korsakoff’s syndrome). In addition to this, the project will provide a better understanding for not only SCA but also basal ganglia and/or cerebellar dysfunction based diseases, and will shed light on investigation of feature treatment and rehabilitation plans.