Patients affected by Parkinson disease (PD) can benefit from rehabilitation although the evidences are scattered. In the last years there are increased evidences that virtual reality can improve functional outcome in Parkinson's disease. No evidences are known concerning the cardiological safety and effect on balance of Virtual Reality. The aim of this study is to compare a virtual reality rehabilitation program versus a conventional one in a sample of patients affected by mild to moderate Parkinson and to collect data on cardiological effects.

This study will be a prospective, single-blinded, randomized controlled trial aimed to compare two different rehabilitation programs in PD disease and to evaluate the effect of Virtual Reality on cardiocirculatory system.

Patients will undergo Conventional or Virtual Reality Rehabilitation Program for 6 consecutive weeks, 3-times in a week for a 40 minute session. Moreover, in order to acquire data on cardiocirculatory system during the first and the last sessions an Holter- electrocardiography will be used. Data will be compared with healthy subjects (matched for age and gender).

The used protocols are reported below.

Conventional (C) Rehabilitation Program The Conventional rehabilitation program will be performed according to the " Royal Dutch Society for Physical Therapy Guidelines for physical therapy in patients with Parkinson's disease". In each C rehabilitation session, patients will undergo 3 phases: 1) Warm-up phase: passive mobilization of main joints and muscular strengthen of lower limbs; 2) Active phase (both standing than seated): exercises of motor coordination with upper and lower limbs, balance training, start and stop exercises, deambulation training; 3) cool-down phase (with seated patient): manipulation exercises, mobilization exercises, respiratory exercises.

Virtual Reality (VR) Rehabilitation Program Each session will consist of multiple exercises. These ones are described below, each exercise will be performed by the patient for 4 minutes followed by a 1 minute of rest.

Exercise 1 (named Trumpet H2D1): patients placed in the center of the room and asked to randomly touch a moving trumpet displayed on the wall screen. When the trumpet will be reached by patient's arm, it will disappear giving out a sound.

Exercise 2 (named Pink rose hemiarch left and right H1D2): patients placed in the center of the room and asked to touch the rose projected on the wall screen as a hemiarch, in this exercise the sequence of rose to touch and therefore the distance between the target and the patient will be decided by the physical therapist.

Exercise 3 (named Doggy): patients placed in the center of the room and asked to lead a dog in the four corner of the wall screen. Patients will be free to move in the room.

Exercise 4 (named Eggs): patients placed in the center of the room and asked to touch as fast as possible eggs projected in the wall screen in a random order. When the egg will be reached by patient's arm, it will disappear giving out a sound.

Exercise 5 (named Mole): patients placed in the center of the room and asked to reach a mole that will go out from a hole. The patients will know where the mole will be and they will move in the room. When the mole will be reached by patient's arm, it will disappear giving out a sound.

Exercise 6 (named Stay Or Move In Between): patients placed in the center of the room and wre asked to perform the motor task as indicated by physical therapist while maintaining balance between two lateral bars in order not to touch them and not make them sound.

Exercise 7 (named Leaves): patients placed in the center of the room and asked to clean from wall screen as fast as possible all the leaves projected in the wall.

Inclusion Criteria:

• Patients affected by mild to moderate PD, according to motor examination section (Part III) of the Unified Parkinson's Disease Rating Scale (UPDRS III)
• ability to independently perform motor rehabilitation
• absence of cognitive impairment (MMSE >25)

Exclusion Criteria:

• severe hearing loss and/or visual deficit
• serious comorbidity making impossible to perform rehabilitation (postural hypotension, heart disease, stroke, severe shoulder-hip disease)