Treatment of Cognitive and Sensorimotor Deficits in Parkinson's Disease With High Definition Transcranial Direct Current Stimulation

Prior treatment

• cranial implants or skull defects that affect tDCS administration;
• any electrically, magnetically, or mechanically activated implants;
• diagnosis of just dysarthria;
  • Use of medications that interact with or potentially interact with tDCS or EEG effects:

Other illness

• history of seizures;
• unexplained episodes of loss of consciousness (as these may be related to brain alterations or epilepsy);
• unstable or uncontrolled neuropsychiatric illness;
• brain tumor; stroke; present drug abuse/misuse;
• serious or life-threatening diseases, including congestive heart failure, chronic obstructive pulmonary disease, or active malignancy;
• Huntington's disease;
• stroke;
• cardiac, neural, or medication implants;
• skin conditions such as dermatitis, psoriasis, or eczema;

Other

• A potentially study-confounding, tDCS-contraindicated, or EEG-contraindicated psychological, neuropsychiatric, neurological, or other medical issues:
• Montreal Cognitve Assessment (MOCA) score \<23, unless an accompanying study partner/caregiver is with them and we can obtain the written consent of both the participant and the participant's accompanying study partner/caregiver (i.e., the participant's spouse, adult child, parent, or adult sibling);
• suffering from severe or frequent headaches;
• severe traumatic brain injury (based on the Ohio State TBI Identification; Method);
• brain tumor;
• implanted brain medical devices, including, deep brain stimulators (DBS);
• implanted pacemakers;
• vascular clips or other electrically sensitive support systems in the brain;
• damaged skin at the sites of stimulation (the device should only be used on healthy, intact skin, as wounds may alter resistance to current);
• pregnant women;
• anti-convulsants;
• carbamazepine;
• sulpiride;
• pergolide;
• lorazepam;
• rivastigmine;
• dextromethorphan;
• D-cycloserine;
• flunarizine;
• ropinirole;
• citalopram;
• stimulants;
  • Additionally, non-English speakers will be excluded because not all of the screening forms, questionnaires, and tests are available in languages other than English.

• Diagnosed with PD having a verbal fluency deficit based on neuropsychological test (T-score \< 40 or a T-score \<-1.0 SD below the average T-score): Semantic Object Retrieval Test (SORT), COWAT (both letter and category fluency), Boston Naming Test (BNT), Rey Auditory Verbal Learning Test (RAVLT)
• 50 - 90 years old
• Capable of understanding and signing an informed consent (able to answer consent comprehension questions)
• Fluent in speaking and reading English