Brain scan study aims to sharpen diagnosis of Parkinson's and dementia

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * Diagnosis of one of the syndromes of interest using established criteria * Age 40-90 inclusive * MMSE score above 10 * No active medical disorder that could preclude participation * Stable medication regimen over previous four weeks * Absence of certain medications that could significantly impact the DaTscan findings * For those with dementia, caregiver that is with the patient at least 4 hours/day for at least 5 days per week * For those with dementia, or severe parkinsonism, patient and caregiver willing and able to participate in all study-related procedures * Patient is capable of giving informed consent, or if appropriate, has caregiver capable of giving consent on the subject's behalf. Exclusion Criteria: * Does not fulfill criteria for any of the desired diagnoses * Age \<40 or \>90 * Women with intact uterus and not post-menopausal unless pregnancy test performed at screening is negative * Women who are pregnant or are breast-feeding an infant * MMSE score \<10 * Active medical disorder that could preclude participation in this protocol * Hypersensitivity to the radioligand, cocaine, or iodine (including seafood allergy) * Myocardial infarction or cerebral infarct over preceding year, stable or unstable angina, known symptomatic coronary artery disease * Renal or liver disease viewed by the physician to be too severe to warrant DaTscan infusion/imaging * History of significant alcohol or drug abuse * Any other medical disorder considered by the study physicians as inappropriate for this protocol * Patient or caregiver unwilling or unable to participate in all study-related procedures * Caregiver is not with a patient with dementia or severe parkinsonism at least 4 hours/day for at least 5 days/week * Patient or caregiver unwilling or unable to provide informed consent