Modafinil for Freezing of Gait (FOG) in Parkinson's Disease (PD)

Freezing of gait is a late stage complication of Parkinson's disease in which patients note that their feet feel stuck or glued to the ground. This can lead to imbalance and falls and the secondary complications that can result from falls such as fractures and hospitalizations. While levodopa can help freezing of gait in some patients, it does not help in all, and the dose needed to treat freezing may be limited by side effects of the medications. Currently there are no treatments targeted towards freezing of gait and the goal of this research is to see if Modafinil could be one such drug to help freezing of gait in Parkinson's disease.

Freezing of gait is a late stage complication of Parkinson's disease in which patients note that their feet feel stuck or glued to the ground. This can lead to imbalance and falls and the secondary complications that can result from falls such as fractures and hospitalizations. While levodopa can help freezing of gait in some patients, it does not help in all, and the dose needed to treat freezing may be limited by side effects of the medications. Currently there are no treatments targeted towards freezing of gait and the goal of this research is to see if Modafinil could be one such drug to help freezing of gait in Parkinson's disease.

Approximately 20 subjects aged 18 or older with idiopathic Parkinson's disease with freezing of gait will be asked to enroll in the study from the patient population in the movement disorders clinic at the University of Arkansas for Medical Sciences (UAMS). Subjects will be assigned randomly 1:1 to an early start and delayed start arm of the study. In the early start arm subjects will receive 24 weeks of 50 mg oral daily Modafinil while subjects in the delayed start arm will receive 12 weeks of placebo followed by 12 weeks of 50 mg oral daily Modafinil. Assessments will be performed prior to initiation of medication at the screening visit, as well as at 12 weeks of the treatment phase. The assessments will include questionnaires to determine the frequency and severity of freezing of gait, level of mood, anxiety and apathy and quality of life, physical examination and tests of cognitive function. Objective assessment of patients walking will be conducted using a pressure sensor impregnated mat at each visit.

Eligibility Criteria:
Inclusion Criteria:

* Diagnosis of idiopathic PD on UK brain bank criteria.
* Presence of FOG based on objective assessment by the movement disorders neurologist.
* FOG-Q score \> 8.
* Stable PD therapy (including medications and stimulation) for a period of 3 months prior to trial enrollment.
* Age ≥ 50 years.

Exclusion Criteria:

* Patients on antidopaminergic medications for a period of less than 1 year from date of enrollment.
* Patients who may require adjustment of their PD medications over the 6 month period of the trial.
* History of allergic reactions to Modafinil or armodafinil.
* Uncontrolled intercurrent illness including, but not limited to, ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia, mitral valve prolapse, left ventricular hypertrophy, chronic obstructive pulmonary disease or psychiatric illness/social situations that would limit compliance with study requirements.
* Individuals who are pregnant or breastfeeding
* Non-english speaking individuals who are unable to complete the questionnaires and other assessments in English and/or follow instructions in English.