Study Rationale:
Many people with Parkinson's disease experience freezing of gait, when the person is unable to move forward, despite his or her best efforts. Although it is not exactly clear why or when freezing occurs, preliminary work suggests two areas of the brain play an important role in this problem; one region controls motor function, in particular, leg movements, and another controls specific aspects of higher-level "executive function."
Hypothesis:
We hypothesize that simultaneous stimulation of specific motor and cognitive areas of the brain using transcranial direct current stimulation (tDCS), a non-invasive, low-cost modality, will improve motor and cognitive functions related to freezing and reduce the frequency and severity of freezing of gait.
Study Design:
People with Parkinson's disease who have documented freezing of gait will receive 10 sessions of either real tDCS or sham (fake) over a two-week period. Freezing of gait and related symptoms will be assessed before and after the 10 sessions. Participants will then receive an additional dose of tDCS or sham stimulation weekly for 12 weeks in order to evaluate relatively long-term effects. The impact of the non-invasive brain stimulation on freezing and related parkinsonian symptoms will be re-evaluated after the 12 weeks to see if the anticipated beneficial effects last.
Impact on Diagnosis/Treatment of Parkinson's Disease:
The results of the study promise to provide important new insights and understandings into the mechanisms that underlie a currently intractable and poorly understood symptom and into the ability to improve brain function in the presence of Parkinson's disease. The findings should also help to establish a new form of treatment for freezing of gait.
Next Steps for Development:
We anticipate that our study will clearly show the clinical benefits of using non-invasive brain stimulation for treating freezing of gait, motor and cognitive function in patients with Parkinson's disease. Based on the hypothesized results, tDCS could already be applied clinically. Future work will be needed to confirm our results and to address questions about optimal dosing and forms of delivery, maintenance, personalization and long-term use.
Trial Phase: Phase II