Evidence suggests the association between fine motor skills of the hand and cognitive function, as well as the positive effects of hand rehabilitation on hand function and the effectiveness of cognitive rehabilitation on cognitive functions in patients with Parkinson's disease (PD). In response to the question of whether there is a cause-and-effect relationship between fine manual skills and cognitive function, we designed the present randomized controlled trial to investigate the effectiveness of sensory-motor rehabilitation of the hand on cognitive functions compared to the effectiveness of cognitive rehabilitation on sensory-motor skills of the hand in patients with PD.

In this double-blinded, randomized controlled trial, a convenience sample including 32 people with PD will participate based on simple non-random sampling. The participants will be allocated randomly through stratified randomization to parallel groups of intervention (sensorimotor hand rehabilitation) and control (cognitive rehabilitation) with a 1:1 allocation ratio. The associate researcher responsible for assessing outcome measures and the statistician responsible for analyzing the data are blinded to the intervention protocol. The intervention protocol for the intervention group includes hand sensory-motor rehabilitation for 10 one-and-a-half-hour sessions, 3 sessions per week, in addition to cognitive rehabilitation for 10 one-and-a-half-hour sessions, 3 sessions per week. The intervention protocol for the control group includes cognitive rehabilitation for 10 one-and-a-half-hour sessions, 3 sessions per week. All participants undergo three assessment sessions: the day before the intervention, the day after the intervention, and one month after the last intervention session. Data will be analyzed using SPSS version 22.0. The significance level will be set at 0.05.

Inclusion Criteria:

1. A diagnosis of PD by a neurologist based on the Movement Disorders Society Clinical Diagnostic Criteria for Parkinson's Disease;
2. 40-65 years old: age of peak incidence of PD;
3. Minimum 2 years and maximum 10 years from initial diagnosis: stabilization of the disease process and medications;
4. disability level of at most 3 in the Modified Hoehn and Yahr Scale: physically independent;
5. Mild cognitive impairment: score between 20 and 26 in Montreal cognitive assessment;
6. Signing the written informed consent.

Exclusion Criteria:

1. Patients with neurological diseases other than PD
2. Patients with orthopedic and internal diseases that would make participation in the study difficult

Statistician responsible for data analysis