Improving Awareness for Spatial Neglect With tDCS

NCT04845529 | Not Yet Recruiting

• 1 other identifier: 2017-01749
• Study Type: interventional
• Target: 12
• Locations: 0 countries
• Sites: N/A

Brief Summary

Brain-damaged patients can show severe neurological and cognitive deficits, and yet often remain strikingly unaware of these symptoms: this condition is called anosognosia. The aim of this study is to improve awareness in right-brain-damaged patients with Unilateral Spatial Neglect (USN) following stroke using transcranial direct current stimulation (tDCS). tDCS is a neuromodulatory technique that delivers low-intensity current to the brain facilitating (anodal tDCS) or inhibiting (cathodal tDCS) spontaneous neuronal activity. tDCS does not induce activity in resting neuronal networks, but modulates spontaneous neuronal activity: consequently, the amount and direction of effects critically depend on the previous state of the neural structures. We will test USN patients showing anosognosia for neglect symptoms. Different brain areas will be stimulated, to target explicit and implicit components of anosognosia, including parietal and frontal brain regions.

Conditions

Stroke; Anosognosia; Neglect, Hemispatial

Keywords

Brain modulation; Recovery; Implicit and explicit anosognosia

Outcome Measures

Primary Outcomes (2)

• Change in self-rating about anosognosia for USN

  We will use a vertical visual scale on a monitor, where the patients should evaluate their performance after each trial of a neglect task.

  from Baseline to 30 minutes

• Change in implicit measures of anosognosia for USN

  Each self-rating will be time-locked with the brain activity of participants in order to record the so-called error-related potentials. Averaged evoked potentials for each domain of awareness will be computed, and a baseline correction will be applied to the epochs. The first error-related component (ERN) will be determined as the mean amplitude in the time window from 60 ms to 140 ms post-response onset; the second component of interest (Pe) will be determined as the mean amplitude in the time-window from 200 ms and 600 ms post-response onset.

  from Baseline to 30 minutes

Secondary Outcomes (1)

• Lesion correlate of recovery of anosognosia for USN

  through study completion, an average of 1 year

Study Arms (3)

1 tDCS Parietal

EXPERIMENTAL

Anodal tDCS applied to the right inferior parietal cortex

Device: transcranial direct current stimulation (tDCS)

2 tDCS Frontal

EXPERIMENTAL

Anodal tDCS applied to the medial frontal cortex

Device: transcranial direct current stimulation (tDCS)

3 Sham

SHAM COMPARATOR

Sham tDCS (control, no stimulation delivered). Following a standard sham protocol, in this condition the tDCS will be active the first 30seconds and the last 30seconds of the session, but silent during the other 19minutes

Device: transcranial direct current stimulation (tDCS)

Interventions

transcranial direct current stimulation (tDCS) DEVICE

We will apply tDCS to the patients' brains for 20 minutes at the intensity of 1.5mA. Each patient will undergo the three sessions (separated by at least 24h to minimize carry-over effects), in a pseudo-randomized order across patients.

1 tDCS Parietal; 2 tDCS Frontal; 3 Sham

Eligibility Criteria

• Age: 20 Years - 85 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• First stroke affecting the right-hemisphere
• Presence of USN, as assessed by a standard neuropsychological evaluation
• Structural images of the brain lesion available (magnetic resonance or tomographic scans)
• Criteria for electrical brain stimulation
• Good (or corrected) visual acuity
• High proficiency in French
• Right-handed

You may not qualify if:

• Presence of general cognitive deficits and/or suspicious of possible cognitive deficits
• Presence of difficulty in task's comprehension
• Impossibility to sustain a research session of at least 45minutes (e.g., attentional lability)
• Precedent additional neurological disorder and/or current or precedent psychiatric disease
• Presence (or suspected presence) of metal in the brain or skull or body (except titanium) (e.g. splinters, fragments, clips, etc.) Presence of cochlear implants, implanted neuro-stimulator (e.g., DBS, epidural/subdural, VNS), cardiac pacemaker, medication infusion device, spinal or ventricular derivations Presence of epilepsy (participant and/or the close family) and/or precedent epileptic seizures (participant) Presence of a fainting spell or syncope, due to neurological diseases (not consider syncope during blood sampling or after being in a warm environment or after emotionally stressful events) Presence of a severe (i.e., followed by loss of consciousness) head trauma Presence of hearing problems or ringing in your ears (e.g. tinnitus) Current treatment under psychoactive (e.g. antidepressants, tranquilizers) or antiepileptic medications Chronic headache For women: you are pregnant or there is any chance that you might be.

Sponsors & Collaborators

• University of Geneva, Switzerland: lead
• University Hospital, Geneva: collaborator

MeSH Terms

Conditions

Stroke; Agnosia; Perceptual Disorders

Interventions

Transcranial Direct Current Stimulation

Condition Hierarchy (Ancestors)

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

Intervention Hierarchy (Ancestors)

Electric Stimulation Therapy; Therapeutics; Convulsive Therapy; Psychiatric Somatic Therapies; Behavioral Disciplines and Activities; Electroshock; Psychological Techniques

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, CARE PROVIDER
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Dr

Study Record Dates

• First Submitted: March 30, 2021
• First Posted: April 15, 2021
• Study Start (Estimated): December 1, 2026
• Primary Completion (Estimated): January 1, 2027
• Study Completion (Estimated): January 1, 2027
• Last Updated: May 30, 2025

Record last verified: 2025-05