No abstract

Although the adoption of more conservative diagnostic criteria identified a lower MCI prevalence, we found evidence that newly diagnosed drug-naive PD patients present a higher risk of MCI in comparison with HCs. Axial symptoms and bradykinesia represent risk factors for MCI in PD patients and a classification of PD patients that highlights the presence/absence of tremor, as proposed in this study, is probably better tailored for the early stages of PD than classifications proposed for more advanced PD stages.

Similar to our healthy control population, we found a significant proportion of early PD patients positive for ICDs before starting treatment. We also found a relationship between impulsivity and depression. A detailed behavioral assessment before starting dopaminergic therapy is recommended.

No abstract

The aim is to study decision making in patients with de novo Parkinson's disease (PD). Recent studies reported that medicated patients with PD have poor performances compared with age-matched healthy controls in decision making tasks, specially in the Iowa Gambling Task. Two principal causal hypotheses have been proposed to explain this phenomenon: the overdosing effects of dopaminergic therapy on the orbital frontostriatal circuit that is involved in reward processing, or an amygdala dysfunction, as suggested by similar Skin Conductance Responses of patients with PD and amygdala-damaged patients while performing this task. The assessment of decision making with the Iowa Gambling Task was conducted in 30 nondemented and nondepressed patients with de novo PD and in 25 age-matched healthy controls. No statistically significant difference emerged between performances of de novo PD patients and performances of healthy controls. De novo PD patients have performances in the Iowa Gambling Task similar to those of age-matched healthy controls, suggesting that difficulties in decision making emerge, at least in de novo PD patients, by dopaminergic overstimulation of the orbital frontostriatal circuits.