Tp determine the effect of IV amantadine on dopaminergic-drug-resistant freezing of gait(FOG)in patients with Parkinson's disease

1. Freezing of gait (FOG) is one of the most disabling symptoms of Parkinson's disease.

   We experienced that severe FOG was markedly improved by IV amantadine in the patients who had Parkinson's disease. But IV drug may have placebo effect. Therefore, We designed double blind, placebo controlled study to know whether IV amantadine is effective in the patient with dopaminergic-drug-resistant freezing of gait(FOG).

2. Cross over study design

   • Compare the change of FOGQ(freezing of gait questionaire) score from the baseline to IV amantadine and placebo drug
   • randomized assigned order of amantadine and placebo drug.
   • investigator of FOG: blinded to the order of drugs
   • each patient has IV drug for 2 days for each drug

Inclusion Criteria

• age: 30-80 years
• idiopathic Parkinson's disease
• The patient must be taking optimised levodopa/DDI therapy (based on investigator's judgement) during OPD observation period, though the patient have FOG-Q score ≥ 10 points even though On-state.

Exclusion Criteria:

• "Off" freezing:The patient has improved FOG in "On" state
• clinically significant or unstable medical or surgical condition
• The patient has Parkinson plus like MSA, PSP, and PPFG, and secondary parkinsonism like NPH, vascular parkinsonism, postencephalitic parkinsonism, CO poisoning.
• history of seizure.