Cognitive and behavioural assessment of parkinsonian syndromes at onset: a longitudinal study

Background: cognitive impairment is one of the non motor features widely descripted in parkinsonian syndrome, it has been related to the motor characteristics of the parkinsonian syndrome, associated with neuropsychiatric dysfunction and the characteristic sleep and autonomic features. It has been shown to be highly prevalent at all disease stages and to contribute significantly to disability. Objectives: aim of this study is to evaluate longitudinally the cognitive and behavioral characteristics of patients with a parkinsonian syndrome at onset; to describe the cognitive and behavioral characteristics of each parkinsonian syndrome; to define in PD patients at onset the presence of MCI or Parkinson disease dementia; to correlate the cognitive and behavioral characteristics with the features of the parkinsonian syndrome and with the associated sleep and autonomic features. Results: we recruited 55 patients, 22 did not present cognitive impairment both at T0 and at T1. 18 patients presented a progression of cognitive impairment. Progressive cognitively impaired patients were older and presented the worst motor phenotype. Progression of cognitive impairment was not associated to sleep and autonomic features. Conclusion: the evaluation of cognitive impairment could not be useful as a predictor of a correct diagnosis but each non motor domain will help to clarify and characterize the motor syndrome. The diagnosis of parkinsonian disorders lies in building a clinical profile in conjunction with other clinical characteristics such as mode of presentation, disease progression, response to medications, sleep and autonomic features.

Adaptive and Maladaptive Implications of Reinforcement Learning Processes: Fronto-Striatal Loops and Behavioural Correlates

That humans and animals learn from interaction with the environment is a foundational idea underlying nearly all theories of learning and intelligence. Learning that certain outcomes are associated with specific actions or stimuli (both internal and external), is at the very core of the capacity to adapt behaviour to environmental changes. In the present work, appetitive and aversive reinforcement learning paradigms have been used to investigate the fronto-striatal loops and behavioural correlates of adaptive and maladaptive reinforcement learning processes, aiming to a deeper understanding of how cortical and subcortical substrates interacts between them and with other brain systems to support learning. By combining a large variety of neuroscientific approaches, including behavioral and psychophysiological methods, EEG and neuroimaging techniques, these studies aim at clarifying and advancing the knowledge of the neural bases and computational mechanisms of reinforcement learning, both in normal and neurologically impaired population.