Inclusion Criteria:

- For Part 1:

• the patient has a DaTscan image, obtained within 1 year (preferably within 6 months) before screening, that shows normal striatal uptake; and
• the patient has a clinical diagnosis (made by a board-certified neurologist who is qualified by training and experience in the diagnosis of movement disorders) that is consistent with the DaTscan image.

For Part 2 (if applicable):

• the patient has a DaTscan image, obtained within 1 year (preferably within 6 months) before screening, that shows abnormal (unilateral or bilateral reduced) striatal uptake; and
• the patient also has a confirmed clinical diagnosis of a dPS (such as Parkinson's disease, multiple system atrophy, corticobasal degeneration, progressive supranuclear palsy, etc.) made by a board-certified neurologist who is qualified by training and experience in the diagnosis of movement disorders; and
• the diagnosis is consistent with the DaTscan image.

- The patient is male or female, ≥18 years of age, of any race and ethnicity.

- The patient is able and willing to comply with study procedures and signed and dated informed consent is obtained.

- If the patient is a woman of childbearing potential*, she must use a highly effective method of contraception** from Screening until 30 days after the last administration
of Altropane, and the results of a serum or urine human chorionic gonadotropin (hCG) pregnancy test, performed at Screening and on the day of Altropane administration
(with the result known before Altropane administration), must be negative.

* A woman of childbearing potential is neither post-menopausal nor surgically sterile.  Post-menopausal means having had no menses for at least 12 months without an
alternative medical cause. Surgically sterile means having had a documented hysterectomy, bilateral salpingectomy, or bilateral oophorectomy, or any combination of these.

** A highly effective method of contraception is one that has a failure rate of less than 1% per year when used consistently and correctly; such methods include combined
(estrogen and progestogen containing) hormonal contraception associated with inhibition of ovulation (oral, intravaginal, or transdermal); progestogen-only
hormonal contraception associated with inhibition of ovulation (oral, injectable, or implantable); intrauterine device; intrauterine hormone-releasing system; bilateral
tubal ligation/occlusion; vasectomized partner (with medical confirmation of success); and abstinence from heterosexual intercourse involving a woman of childbearing potential.

- If the patient is a male*** with a sexual partner who is a woman of childbearing potential*, he and his partner must use adequate contraception** from Screening until
30 days after the last administration of Altropane.

(***A male is considered fertile after puberty unless permanently sterile by bilateral orchidectomy, or vasectomized with confirmation of success.)

Exclusion Criteria:

- The patient was previously included in this study.

- Fewer than 7 disintegration half-lives have elapsed between the patient's last procedure (therapeutic or diagnostic) involving a radioisotope and Visit 2 (altropane
SPECT imaging).

- Including participation in this study, the patient's total exposure to radiation during medical procedures/tests in the past year would exceed 50 mSv.

- The patient has participated in an investigational drug or device clinical trial within 30 days before the date of informed consent.

- The patient has any clinically significant or unstable physical or psychological illness, structural brain abnormality, abnormal laboratory results, or abnormal ECG (based on medical history or physical examination at Screening), as determined by the Principal Investigator, that would interfere with study participation.

- The patient has any history of drug or alcohol abuse in the 2 years prior to the date of informed consent.

- The patient has a positive urine screen for drugs of abuse at Screening.

- The patient is a pregnant or breast-feeding female, or is a female of child-bearing potential that is not using appropriate birth control.

- The patient is unable to lie supine for 1 hour.

- The patient has any thyroid disease other than adequately treated hypothyroidism.

- The patient has known or suspected allergy/hypersensitivity to any ingredient in Altropane or to the thyroid blocking medication to be used before imaging.

- The patient is currently taking any of the medications/ treatments listed in the protocol as disallowed and cannot or will not discontinue use at least 12 hours prior to SPECT exam.

- The patient was referred to DaTscan imaging for evaluation of possible cognitive impairment including dementia.

Note: Other protocol defined Inclusion/Exclusion Criteria may apply.

Eligibility last updated 11/15/23.  Questions regarding updates should be directed to the study team contact.