Clinical, functional and cognitive data from Parkinson's disease patients in an action-verb processing tDCS study

Data collected from 22 Parkinson's Disease (PD) patients on clinical and functionality measures including GDS (depression), Lawton and Brody, Barthel Index, UPDRS-III, also cognitive tasks including ACE-R and IFS and data (RT and accuracy) from a picture-word association (PWA) task assessing action-verbs processing, which was applied twice (pre-post) in the context of a tDCS study.

Patients were randomly assigned to either an anodal tDCS group (n=11) or a sham tDCS group (n=11). Anode was placed on C3 (10-20 international system), which corresponds approximately to left M1 region, and cathode was placed on FP2. We used 25 cm2 circular electrodes soaked in saline solution. Each stimulation session lasted 20 min with a current intensity of 2 mA, ramped up for 30 s at the beginning and ramped down for 30 s at the end. Patients underwent three consecutive days of stimulation, one session per day. During stimulation, patients performed a PWA task with different stimuli from those used to get the pre and post measurements.

All participants were right-handed, had normal or corrected-to-normal vision. PD patients diagnosis was confirmed by an expert neurologist, in accordance with the UKPD society brain bank criteria. All patients were in the on phase and had no other neurological/psychiatric conditions.

All participants read and signed a consent form in agreement with the Declaration of Helsinki. The study was approved by the Ethics Committee of Universidad del Valle.

The PWA tasks consisted of 80 trials (40 action verbs, 40 nouns) in which participants decided if a word matched a black and white picture by pressing one of two keyboard buttons (match or no match). Also in each condition there were 20 congruent trials and 20 incongruent trials. Pictures were extracted from Druks & Masterson’s (2000) action-picture set and the International Picture-Naming Project Corpus (2003).