Eligibility Criteria:
Inclusion Criteria:
Participants aged 30-80 years old with a diagnosis of Possible or Probable MSA of the parkinsonian subtype (MSA-P) or cerebellar subtype (MSA-C)
Participants who are less than 4 years from the time of documented MSA diagnosis
Participants who are willing and able to give informed consent
"Normal" cognition as assessed by Mini Mental State Examination
Exclusion Criteria:
Pregnant or lactating females
Participants with a clinically significant or unstable medical or surgical condition that, in the opinion of the investigator, might preclude safe completion of the study or might affect the results of the study. These include conditions causing significant CNS or autonomic dysfunction, including congestive heart failure, recent (\<6 months) myocardial infarction, thrombocytopenia (\<50 x 10(9)/L), immunosuppressed state, severe uncontrolled hypertension, severe cardiopulmonary disease, severe anemia (hemoglobin \<8g/dl), severe liver or kidney disease (creatinine \>2.3 mg/dl) uncontrolled diabetes mellitus (HbA1c \>10g%), alcoholism, malignant neoplasms, amyloidosis, uncontrolled hypothyroidism, unstable peripheral neuropathies, concurrent infections, orthopedic problems that compromise mobility and activities of daily living, severe cerebrovascular accidents (causing symptoms such as hemiplegia, aphasia and non-dominant parietal lobe syndrome), and neurotoxins or neuroactive drug exposure, parkinsonism due to drugs (including neuroleptics, L-methyldopa, reserpine, metoclopramide).
Females who are pregnant
Subjects known to have porphyria
The regular use of neuroleptics within the six months prior to the initial evaluation. Occasional use of a neuroleptic as an anti-emetic in the past is allowed, providing not more than three doses were taken within the previous 12 months
Diseases more consistent with Lewy Body dementia, progressive supranuclear palsy, essential tremor, inherited cerebellar degeneration, or postencephalitic parkinsonism
Subjects receiving psychostimulants, antimuscarinics (trihexphenidyl, benztropine, and tricyclic antidepressants), acetylcholinesterase inhibitors, trazodone or modafinil will be excluded as they may interfere with study measures. Subjects with prior exposure to disallowed medications may be eligible if there has been an interval of \> 2months for these medications, at the discretion of the investigators
Dementia (DSM-IV criteria - Amer. Psych. Association, 1994). The score on the Mini-Mental State Examination must be \>24