 This study is an observational study to assess FOG via using multiple methods such as: clinical features, imaging, cognition and dopamine blood levels. The study consists of four parts plus an optional fifth part that will be completed over two-three separate days within a 30 day span. The four parts will not necessarily be performed in this order. Part one will be clinical and written questionnaire assessments of PD and FOG followed by 3D motion capture evaluations. Part two are cognitive or neuropsychiatric assessments. Part three is a magnetic resonance image MRI to examine the brain structure. Part four is Positron Emission Tomography PET imaging scan that measures norepinephrine transporter levels. The optional part 5 is a lumbar puncture that will measure cerebrospinal fluid catecholamines and proteomics. 