Efficacy Study of Amantadine to Treat Gait Dysfunction and Freezing in Parkinson's Disease

Subjects who meet the eligibility requirements for the study will be randomized to
Amantadine versus a matching placebo.

Inclusion Criteria:

1. Subjects with idiopathic PD as determined by UK brain bank diagnostic criteria

2. H&Y stage 2.5-3

3. Presence of freezing of gait (FOG) as determined by UPDRS Part I score > 2

4. Ability to walk for 2 minutes in the ON and OFF state

5. Stable regimen of PD medications for 30 days prior to screening

6. Ability to comply with the study procedures

7. If female, be either post menopausal for at least 2 years, surgically sterilized or
have undergone hysterectomy or, if of child bearing potential they must be willing to
avoid pregnancy by using an adequate method of contraception as defined in Section
6.4.10 for four weeks prior to, during and four weeks after the last dose of trial
medication. For the purposes of this trial, women of childbearing potential are
defined as all female subjects after puberty unless they are post-menopausal for at
least two years, are surgically sterile or are sexually inactive.

8. Willing and able to provide informed consent.

Exclusion Criteria:

1. Presence of other co morbid conditions that can contribute to gait dysfunction
(orthopedic, rheumatologic, cardiac, other)

2. Presence of freezing of gait (FOG) ONLY in medications ON state

3. Presence of freezing of gait (FOG) ONLY in medications OFF state

4. Presence of significant cognitive dysfunction as determined by Montreal Cognitive
Assessment (MoCA) <20

5. Presence of clinically significant depression as determined by geriatric depression
scale (GDS)- 15>5

6. Presence of clinically significant hallucinations

7. Inability to sign informed consent

8. Participation in the physical therapy aimed at management of PD for the duration of
the study (PT for orthopedic issues will be allowed)

9. Contraindications for use of Amantadine ( prior history of allergic reaction, history
of known renal insufficiency with Cr > 2)

10. If female, be pregnant or lactating