ParkinStim: Transcranial Direct Current Stimulation for Parkinson's Disease

The clinical study will follow a counterbalanced crossover design during which subjects will undergo two separate pairs of two-consecutive-overnight sleep studies and receive anodal tDCS (active or sham) to M1. The first sleep study in each pair will acclimate subjects to the sleep laboratory and minimize "first night" effects, thus no tDCS will be applied. The second sleep study in each pair will include active or sham tDCS, presented in a pseudorandom order such that approximately half of the subjects receive active tDCS first while the other half receives sham first. The two pairs of sleep studies will be separated by one to three weeks.

Inclusion criteria

• Clinical diagnosis of idiopathic Parkinson's disease (PD) according to the UK PD brain bank criteria
• Hoehn and Yahr stage II-III when off anti-parkinsonian medication
• Able to provide informed consent
• Currently taking levodopa (300-800 mg per day)
• On stable regimen of anti-parkinsonian medication for at least one month before study entry and able to continue on a stable regimen for the duration of the study
• Presence of early morning akinesia
• Naïve to tDCS.

Exclusion criteria

• Children will be excluded from this study due to the fact that they are unlikely to have PD
• Significant medical or psychiatric illness, significant neurological disease other than PD, metal objects and/or deep brain stimulators in the head that might pose a hazard during tDCS
• Dementia, as evidenced by a score less than 26 on the Montreal Cognitive Assessment
• Significant depression (Geriatric Depression Scale score < 20)
• Presence of hallucinations
• Having undergone any surgical procedure for treatment of PD including deep brain stimulation (DBS), pallidotomy, thalamotomy, or other brain surgeries
• A history of seizures
• A known history of severe sleep apnea or sleep onset insomnia
• Skin diseases that could potentially cause irritations under electrodes