|Tipo di tesi||Tesi di dottorato di ricerca|
|Autore||PETRELLI, BARBARA CAROLINE|
|Titolo||Correlati cognitivi ed emozionali dell'apatia nella malattia di Parkinson|
|Titolo in inglese||Cognitive and emotional correlates of apathy in Parkinson's disease|
|Settore scientifico disciplinare||MED/26 - NEUROLOGIA|
|Corso di studi||Scuola di D.R. in NEUROSCIENZE|
|Data inizio appello||2016-03-16|
|Disponibilità||Accessibile via web (tutti i file della tesi sono accessibili)|
Background. L'apatia è uno dei disturbi comportamentali più disabilitanti per i pazienti con malattia di Parkinson (MP), con una stima di prevalenza che varia dal 17% al 70%. L'apatia è stata definita come la riduzione quantitativa della volontà di realizzare azioni e comportamenti finalizzati. Sembra dipendere da una disfunzione a livello della corteccia prefrontale e dei gangli della base successiva ad un'interruzione dei circuiti fronto-sottocorticali. L'apatia risulta spesso associata ad alterazioni della funzioni esecutive. Oltre alle disfunzioni cognitive, sono state osservate anche alterazioni dell'elaborazione delle emozioni e dei processi decisionali. La MP è caratterizzata da un'insorgenza asimmetrica dei sintomi motori. Recenti studi hanno osservato un'asimmetria nella deplezione dopaminergica associata alla sensibilità alla ricompensa e al comportamento di avversione per la perdita.
Background. Apathy is a one of the most disabling behavioral disorders in patients with Parkinson's disease (PD), with a prevalence ranging from 17% to 70%. Apathy is defined as the quantitative reduction of the willingness to perform actions and purposeful behaviors. It seems to depend on a dysfunction in the prefrontal cortex and the basal ganglia following an interruption of fronto-subcortical circuits. Apathy is often associated with impairment of executive functions. In addition to cognitive dysfunction, they were also observed alterations in emotion and decision-making processing. The PD is characterized by asymmetric onset of motor symptoms. Recent studies have observed asymmetry in the dopaminergic depletion associated with sensitivity to reward. Aim of the study. The goal of the study was to investigate the relationship between apathy and executive dysfunction, assess the sensitivity to gain and loss in apathetic PD patients employing a "loss aversion task" that included both primary (juice) and secondary (money) rewards and determine whether different patterns of asymmetry dopamine loss were associated with effort to increase the gain or effort to avoid the loss. Methods. Patients with idiopathic PD were assessed in two sessions of study. During the first session, the patients were tested in "on" condition (taking all their medications as usual) and underwent to a comprehensive neuropsychological battery, psychological and behavioral assessment by means of questionnaires/interviews and the computerized task. In the second session, patients were seen during the "off" condition (i.e., after an overnight withdrawal for at least 12 hours of dopamine replacement therapy) and evaluated exclusively with the computerized task and a scale on motor disability. The results were compared with a control group, that is healthy subjects without PD matched for age and education. Results. Apathy but not depression was associated with specific deficit of cognitive functioning. We found that the executive impairment mainly related to logical-analogical reasoning, verbal conceptualization, response inhibition and mental flexibility. Best predictors of executive dysfunction were the apathy as measured by the LARS global score and intellectual curiosity and action initiation subscores that reflecting respectively cognitive and behavioral dimensions of apathy. Any difference was found between PD patients and healthy control concerning performance on loss aversion task, as well as any difference was observed between apathetic and non-apathetic patients on sensitivity to gain and loss. PD patients with motor signs predominant to right side showed a higher loss aversion for juice compared to patients with motor sings predominant to left side when tested in on medication. This is an opposite pattern found by previous studies. Conclusion. These findings suggest that apathy was related to executive impairment but not to an altered reward processing. Furthermore, it was found that asymmetry of dopamine signaling appears to influence the response to a primary reward in patients with predominant left-hemisphere dopamine deficit when are on their usual medication. This study requires replication in lager samples.