Multiple system atrophy (MSA) is a sporadic neurodegenerative disorder. MSA is dominated by autonomic/urogenital failure which may be associated with either Parkinsonism (MSA-P subtype) or with cerebellar ataxia (MSA-C subtype). The prognostic of this disease is bad because it ended with the patient's death few years later. No neuroprotective treatment has shown a real efficacy. 50% of patients suffering of MSA frequently experienced painful sensation. The origin of this pain is unknown. In Parkinson disease (PD) ; arguments suggest the implication of dopamine neuromediator pathway in integration and modulation of pain. Several studies suggest the existence of various influences with dopamine implication in the appearance of painful sensation and that would be inhibitory. That's why observed painful symptoms in MSA and PD could be due to a decrease of pain appearance threshold, secondary to a lost of control of sensitizes centres, to Parkinson control.