Effect of Anodal Transcranial Direct Current Stimulation (tDCS) Over the Right-hemisphere on Picture Naming in Chronic Aphasia

The Effect of tDCS Stimulation of Right Inferior Frontal Gyrus on Language Recovery in Speakers With Aphasia

There are two opposing hypotheses, namely the interference and laterality-shift hypotheses, regarding the role of the right hemisphere (RH) in language recovery following a left hemisphere damage. Transcranial direct current stimulation (tDCS) has received increasing attention as a potential complement to behavioural therapy.

This preliminary study aimed to examine the effect of excitatory (anodal) stimulation of right inferior frontal gyrus (IFG) on naming abilities of chronic people with aphasia (PWA) to examine the compensatory versus interference role of RH in language recovery, and to confirm the application of tDCS does not induce adverse effects on other cognitive and language functions.

Study Overview

• Status: Completed
• Conditions: Aphasia
• Intervention / Treatment: Device: tDCS stimulation

• Study Type: Interventional
• Enrollment (Actual): 4
• Phase: Not Applicable

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 40 years to 90 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• People with chronic aphasia following the stroke

Exclusion Criteria:

• history of seizure or epilepsy,
• previous adverse reactions to TMS/tDCS,
• having a pace-maker or a metal implanted in the brain
• being pregnant

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: anodal tDCS; 20 minutes of one mA anodal High-Definition tDCS (HD-tDCS) over right IFG combined with 40 minutes of naming therapy for five consecutive days in week 1	Device: tDCS stimulation; The study examines the effect of excitatory stimulation of right inferior frontal gyrus (IFG) on naming abilities of people with aphasia (PWA) as compared to sham stimulation to examine the compensatory versus interference role of right hemisphere in language recovery after stroke.; Other Names: language therapy
Sham Comparator: sham tDCS; 20-minutes sham HD-tDCS with 40-minutes therapy of naming therapy for five consecutive days in week 1	Device: tDCS stimulation; The study examines the effect of excitatory stimulation of right inferior frontal gyrus (IFG) on naming abilities of people with aphasia (PWA) as compared to sham stimulation to examine the compensatory versus interference role of right hemisphere in language recovery after stroke.; Other Names: language therapy

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Picture naming task	One hundred and sixty pictures of concrete nouns from the Snodgrass and Vanderwart (1980) picture set (colored version) were utilised to measure the percentage of object naming accuracy. In particular, these pictures were divided into Set A (training targets) and Set B (untrained generalization targets), with eighty stimuli in each set.	Immediately after the end of each treatment session and block

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
language task	* Overall language skills are measured through the overall aphasia scores provided by the Cantonese version of Western Aphasia Battery (short-form). The scale is called Aphasia quotient: Minimum value = 0, maximum value = 100, with higher scores mean a better performance.	Immediately after the end of each treatment block
Cognitive task	The cognitive skills are measured through the subtest scores provided by Oxford Cognitive Screening-Cantonese. The test uses different sub-tests including the Picture naming, Semantics, Orientation, Visual field task, Sentence reading , Calculation, Attention, Praxis, Memory, and Executive tasks. The range of values varies across the subtests. For all subtests except the executive task, the higher scores reflect better performance. For executive tasks the lower scores reflect better performance.	Immediately after the end of each treatment block

Collaborators and Investigators

• Sponsor: The University of Hong Kong

Study record dates

Study Major Dates

• Study Start (Actual): January 1, 2017
• Primary Completion (Actual): November 1, 2017
• Study Completion (Actual): December 20, 2017

Study Registration Dates

• First Submitted: July 18, 2022
• First Submitted That Met QC Criteria: July 21, 2022
• First Posted (Actual): July 25, 2022

Study Record Updates

• Last Update Posted (Actual): November 4, 2022
• Last Update Submitted That Met QC Criteria: November 1, 2022
• Last Verified: November 1, 2022

More Information

Terms related to this study

• Keywords: tDCS; Aphasia; naming
• Additional Relevant MeSH Terms: Nervous System Diseases; Neurologic Manifestations; Neurobehavioral Manifestations; Language Disorders; Communication Disorders; Speech Disorders; Aphasia
• Other Study ID Numbers: tDCSAphasia

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: No

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No