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

Not Applicable

Completed

• Conditions: Aphasia
• Interventions: Device: tDCS stimulation

• Registration Number: NCT05471570
• Lead Sponsor: The University of Hong Kong

Brief Summary

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.

Detailed Description

Not available

Study Timeline

• Study Start: 2017-01-01
• Primary Completion: 2017-11-01
• Study Completion: 2017-12-20
• Study First Submitted: 2022-07-18
• Study First Submitted QC: 2022-07-21
• Study First Posted: 2022-07-25
• Status Verified: 2022-11
• Last Update Submitted: 2022-11-01
• Last Update Posted: 2022-11-04

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 4

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 & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
sham tDCS	tDCS stimulation	20-minutes sham HD-tDCS with 40-minutes therapy of naming therapy for five consecutive days in week 1
anodal tDCS	tDCS stimulation	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

Primary Outcome Measures

Name	Time	Method
Picture naming task	Immediately after the end of each treatment session and block	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.

Secondary Outcome Measures

Name	Time	Method
language task	Immediately after the end of each treatment block	\* 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.
Cognitive task	Immediately after the end of each treatment block	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.