The researchers aimed to investigate the relationship between the asymmetric dopaminergic degeneration and the attentional resources in a group of patients with Parkinson's disease (PD).

To bypass the impaired habitual motor-behavioural control, Parkinson's disease (PD) patients may exploit the network of goal-directed mode of action. The frontostriatal connections underline this functioning, that is based on attention. Since the cognitive processes are related with dopamine, the asymmetrical degeneration of the dopaminergic system affects differently the right side affected (RPD) and the left side affected (LPD) PD patients.

The aim of the study was to investigate the relationship between the asymmetric dopaminergic degeneration and the attentional resources in a group of patients with PD.

Inclusion Criteria:

• Stage 2.5-3 according to the Hoehn and Yahr scale (H&Y);
• Stable pharmacological treatment for the last 6 weeks before the enrolment and during the hospitalization;
• Mini Mental State Examination (MMSE) ≥ 24;
• No evidences of dysexecutive syndrome.

Exclusion Criteria:

• Any focal brain lesion detected in brain imaging studies (CT or MRI) performed in the previous 12 months;
• Drug-induced dyskinesias;
• Disturbing resting and/or action tremor, corresponding to scores 2-4 in the specific items of UPDRS III;
• Behavioral disturbances (evaluated with Neuropsychiatric Inventory);
• Visual and auditory dysfunctions according to the general clinical evaluation and medical history;
• Equivocal report about the side of disease onset or bilateral motor involvement.