The Influence of Low Frequency Repetitive Transcranial Stimulation (r-TMS) on Motor and Cognitive Measurements in Patients With Asymmetric Parkinson's Disease

PD patients with asymmetric disease aged 40 years or older, diagnosed as idiopathic PD according to the UK Brain Bank criteria, with Hoehn & Yahr stages II - IV while "off" will be recruited. Participants on antidepressants should be at least 2 months on stable therapy.

Patient will be excluded if:

1. They have concomitant epilepsy, a history of seizure or heat convulsion or history of epilepsy in first degree relative.
2. Are on neuroleptics.
3. Have dementia or any unstable medical disorder.
4. Have a history or current unstable hypertension.
5. Have a history of head injury or neurosurgical interventions.
6. Have a history of any metal in the head (outside the mouth).
7. Have a known history of any metallic particles in the eye, implanted cardiac pacemaker, implanted neurostimulators, surgical clips (above the shoulder line) or any medical pumps.

Patients will be randomized into two groups: The first group of patients will receive an active unilateral stimulation over the motor cortex contralateral to the more affected body side (1Hz stimulation 110% of the MT for 15 minutes). Patients in the second group will receive a similar rTMS stimulation pattern over the motor cortex and over the prefrontal cortex (10Hz stimulation 100% of the MT, 2 seconds each train, 20 seconds between trains, for 15 minutes).

The following outcome measures will be taken prior to the treatment (screening visit), and at day 1, 10, 30 and 60 Evaluation will be while subjects both at "on" and "off".