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

NCT06776978 | Completed

• 1 other identifier: CE/prog.733
• Study Type: interventional
• Target: 32
• Locations: 1 country
• Sites: 1

Brief Summary

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.

Conditions

Aphasia Non Fluent; Stroke

Keywords

Transcranial Direct Current Stimulation; Aphasia; Verb Naming; Language Rehabilitation; Speech Therapy; Stroke

Outcome Measures

Primary Outcomes (1)

• Action Naming Task

  An action naming task was designed to evaluate verb naming performance. Video clips depicting various actions were presented on a 15-inch computer screen at a viewing distance of 1 meter, each preceded by an 800-millisecond fixation point. Participants were instructed to name the action depicted in each clip within a 15-second response window. The examiner manually recorded correct responses. For incorrect responses or failures to respond within the allotted time, the written name of the action was displayed beneath the video, and participants were required to read the name aloud. The video and the written name remained on the screen until the word was read correctly or 40 seconds had elapsed. The task was conducted during 20-minute tDCS sessions, wherein participants received either active stimulation targeting Broca's area or sham stimulation with identical electrode placement but no active current.

  Verb naming performance was assessed at baseline (pre-treatment), post-treatment (immediately after the 10-day intervention), and at follow-up (one month after each treatment condition) to evaluate both immediate effects and the stability of responses.

Study Arms (2)

Active tDCS

EXPERIMENTAL

Participants receive anodic tDCS over Broca's area at 2 mA for 20 minutes per session, 5 days per week for 2 consecutive weeks.

Device: Active treatment

Sham tDCS

SHAM COMPARATOR

Participants receive sham tDCS for 20 minutes per session, 5 days per week for 2 consecutive weeks.

Device: Sham Stimulation

Interventions

Active treatment DEVICE

Participants receive anodic tDCS using a battery-driven Eldith (neuroConn GmbH) Programmable Direct Current Stimulator with surface-soaked sponge electrodes (5×7 cm). A constant current of 2 mA is applied for 20 minutes per session. The stimulation targets the left frontal region (F5 of the extended International 10-20 EEG system), corresponding to Broca's area, while the reference electrode is placed over the contralateral frontopolar cortex. tDCS is performed for 10 daily sessions over two consecutive weeks (5 days per week).

Active tDCS

Sham Stimulation DEVICE

Participants receive sham tDCS using a battery-driven Eldith (neuroConn GmbH) Programmable Direct Current Stimulator with surface-soaked sponge electrodes (5×7 cm). No therapeutic current is applied during the 20-minute session. The electrode placement mimics the active condition, targeting the left frontal region (F5 of the extended International 10-20 EEG system), corresponding to Broca's area, while the reference electrode is placed over the contralateral frontopolar cortex. Sham tDCS is performed for 10 daily sessions over two consecutive weeks (5 days per week).

Sham tDCS

Eligibility Criteria

• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)

You may qualify if:

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

You may not qualify if:

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

Sponsors & Collaborators

• I.R.C.C.S. Fondazione Santa Lucia: lead

Study Sites (1)

I.R.C.C.S. Fondazione Santa Lucia

Roma, Italy, 00179, Italy

Location

Related Publications (3)

• Syka J, Melichar I. The effect of loop diuretics upon summating potentials in the guinea pig. Hear Res. 1985;20(3):267-73. doi: 10.1016/0378-5955(85)90031-0.

  PMID: 3003019 BACKGROUND

• Nishitani N, Schurmann M, Amunts K, Hari R. Broca's region: from action to language. Physiology (Bethesda). 2005 Feb;20:60-9. doi: 10.1152/physiol.00043.2004.

  PMID: 15653841 BACKGROUND

• Marangolo P, Fiori V, Di Paola M, Cipollari S, Razzano C, Oliveri M, Caltagirone C. Differential involvement of the left frontal and temporal regions in verb naming: a tDCS treatment study. Restor Neurol Neurosci. 2013;31(1):63-72. doi: 10.3233/RNN-120268.

  PMID: 23142815 BACKGROUND

MeSH Terms

Conditions

Aphasia, Broca; Stroke; Aphasia; Communication Disorders

Condition Hierarchy (Ancestors)

Speech Disorders; Language Disorders; Neurobehavioral Manifestations; Neurologic Manifestations; Nervous System Diseases; Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Cerebrovascular Disorders; Brain Diseases; Central Nervous System Diseases; Vascular Diseases; Cardiovascular Diseases; Neurodevelopmental Disorders; Mental Disorders

Study Officials

• Carlo Caltagirone, MD, PhD

  Fondazione Santa Lucia, Via Ardeatina 306, 00179 Roma, Italy

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: January 10, 2025
• First Posted: January 15, 2025
• Study Start: December 4, 2023
• Primary Completion: December 13, 2024
• Study Completion: December 13, 2024
• Last Updated: January 15, 2025

Record last verified: 2025-01

Data Sharing

• IPD Sharing: Will not share

Locations

IT (1)