To examine if anodal transcranial direct current stimulation (atDCS) to the left dorsolateral prefrontal cortex (l-DLPFC) improves cognitive function and reduces cognitive fatigue and fatigability in Parkinson’s Disease (PD) patients.

PD is the second most common neurological condition, affecting roughly 1 million people in the United States. Non-motor symptoms, such as cognitive impairment and fatigue, can significantly reduce quality of life in Parkinson’s patients. However, treatment plans are typically dominated by motor symptoms. There is increasing need to advance standard treatments for the non-motor symptoms of PD. Recently, tDCS has been explored as a potential non-invasive treatment for these non-motor symptoms.

A randomized, single-blind, placebo-controlled experiment comparing a control group with an experimental group subjected to 5 consecutive days of 2mA tDCS for 20 minutes. PD patients were recruited from a movement clinic in the US and met clinical diagnosis of PD with a MOCA  > 21. Primary and secondary outcome measures, assessing complex attention, working memory, fatigue, and fatigability, were completed at the initial visit after screening, the fifth day, and at one and two-week follow-up visits.

Total of 38 participants were recruited (tDCS-19, sham-19), with 3 participants being excluded due to adverse weather, or MOCA below 21. At 1 week, MFI-Mental sub-score and total fatigued were reduced in tDCS compared to the sham. Although approaching significance, tDCS at the study’s parameters showed no immediate or long-term effects on cognitive function.

This study highlights that tDCS, a non-invasive and relatively safe procedure, may potentially be effective for managing mental and total fatigue in PD patients.