Effectiveness of TDCS Over Broca's Area in Verb Naming: a Randomized, Double-Blind, Crossover Study

La Stimolazione Transcranica (tDCS) E Transpinale a Corrente Diretta (tsDCS) Per Il Recupero Delle Funzioni Cognitive in Soggetti Affetti Da Patologia Cerebrovascolare O Neurodegenerativa

This clinical trial investigated whether transcranial direct current stimulation (tDCS) over Broca's area (F5) could improve verb naming abilities in adults with aphasia. Additionally, the study evaluated the stability of the treatment response to tDCS over time.

The main questions this study sought to answer were:

• Does tDCS improve verb naming abilities compared to inactive (sham) stimulation?
• Are the observed effects stable over time?

Participants received 10 daily sessions of tDCS over two consecutive weeks (5 days per week). The study included two treatment conditions, separated by one-month washout period:

• Active tDCS: Stimulation over Broca's area at 2 mA;
• Sham tDCS: Stimulation mimicking the active condition without delivering electrical current.

During the treatment, participants were asked to name aloud videos of actions displayed on a computer screen. One month after each treatment condition, follow-up testing was conducted to evaluate the stability of the treatment response.

Inclusion Criteria:

• native Italian proficiency;
• pre-morbid right-handedness;
• a single left hemispheric stroke at least 6 months before the investigation.

Exclusion Criteria:

• acute or chronic neurological symptoms requiring medication;
• attention and/or memory deficits.