Therapeutic Effects of Transcranial Alternative Current Stimulation (tACS) in Chronic Post Stroke Hemianopia

NCT04043689 | Completed

• 2 other identifiers: APHP 1900512019-A00501-56
• Study Type: interventional
• Target: 43
• Locations: 1 country
• Sites: 1

Brief Summary

Background: The most common visual field deficit after retro-chiasmatic lesions is homonymous hemianopia (HH), defined as the impossibility of seeing the contralesional visual hemisphere without ocular injury. HH affects between 90000 and 120 000 new cases per year in the United States and Europe HH was reported in 30% of patients after stroke (National Audit Office) (in France, with 130,000 strokes per year, 39,000 patients with HH). Despite the 30-year decline, the rehabilitation techniques have a low level of evidence of their effectiveness and few are used in routine clinical practice in France. Transcranial Alternate Current Stimulation (tACS) is a method of Alternative Current stimulation that can modulate neural activity by imposing local oscillatory activity. An observational study of occipital tACS in patients with optic nerve lesions showed an increase in visual field size, power, and occipital alpha synchrony. Two transorbital tACS studies showed visual improvements , and compensations for abnormally weak oscillatory activity by temporal resynchronization. Our team has demonstrated a role of noninvasive brain stimulation in right hemisphere frontal eye fields on cortical beta-high (\~ 30 Hz) oscillatory activity, improving the visual perception of both hemi-fields and the fronto-parietal synchrony of the right hemisphere. Objective: This project aims to compare, on the same patient population, two tACS stimulation strategies, with the aim of increasing the attentional orientation towards the blind visual hemi-field and thus the visual detection of stimuli in this hemi-field. . For this, The investigator team will evaluate on the one hand an occipital stimulation (V1-IPS) contralateral to the lesion, at a alfa frequency (10 Hz), which induces the desynchronization of the contralateral hemisphere with the aim of improving the visual perception of targets in the blind visual hemi-field. the study will compare this intervention to a stimulation of the frontal region (FEF) of the right hemisphere at a high-beta frequency (30 Hz), which showed effects of facilitation of endogenous and exogenous attentional orientation. The two previous strategies will be compared to a placebo tACS stimulation session.

Conditions

Hemianopsia

Outcome Measures

Primary Outcomes (1)

• To evaluate the immediate effect of a single tACS session on the static visual field size of patients with chronic phase HH

  To evaluate the immediate effect of a single tACS session, under two different conditions of tACS stimulation (right frontal stimulation (FEF, Frontal Eye Fields) and contralateral occipito-parietal stimulation to the lesion (V1-IPS, primary visual cortex and intraparietal sulcus or intra-parietal furrow) on the static visual field size of patients with chronic phase HH

  Immediately after the intervention

Study Arms (3)

tACS stimulation of the right frontal region

ACTIVE COMPARATOR

Active tACS stimulation of the right frontal region (around the right FEF, EEG electrode FC2) at a high-beta frequency (30 Hz) with the goal of visibly training EEG recordings, frontal oscillatory activity and right fronto-parietal synchrony (FEF-IPS, or between FC2 and P4 electrodes) in the high-beta band (\~ 30 Hz) which facilitates attentional orientation and visual perception in the two visual hemi-fields, but more particularly the targets present on the blind field of vision.

Device: tACS (transcranial Alternate Current Stimulation)

tACS stimulation of the occipito-parietal region

ACTIVE COMPARATOR

Active tACS stimulation of the occipito-parietal posterior contralesional region(around the right IPS, EEG electrode P4), at an alpha frequency (10 Hz) which will induce on the EEG recordings an oscillatory drive in the alpha band ( \~ 10Hz) and an increase in synchrony at this frequency band on the stimulated posterior occipital and parietal lobe (EEG electrodes P4 and 02), but also, by transcallosal push-and-pull phenomena, a desynchronization effect of the contralateral posterior occipital and parietal area (EEG electrodes P3 and 01), which will facilitate attention orientation and target detection in the blind visual field of view.

Device: tACS (transcranial Alternate Current Stimulation)

TACS stimulation of the right frontal (FEF)

SHAM COMPARATOR

. Condition TACS stimulation of the right frontal (FEF) at a high-beta frequency (30 Hz) for half of the patients and unilateral occipital cortex (right / left) at an alfa frequency (10 Hz) for the other half . This condition will control the possible placebo effects of tACS stimulation and the potential effects of visual field enhancement with repetition of perimetry tests. This condition will also verify the lack of changes in cerebral rhythm activity in the case of an application without effective electrical current.

Device: tACS (transcranial Alternate Current Stimulation)

Interventions

tACS (transcranial Alternate Current Stimulation) DEVICE

This is a single-centric comparative randomized controlled blind and cross-over study. The order of stimulation conditions will be randomized: (right frontal tACS / occipital tACS / tACS PLACEBO). The 3 stimulation conditions will be performed with a wash-out period of at least 1 week. In this study each patient will be his own control

TACS stimulation of the right frontal (FEF); tACS stimulation of the occipito-parietal region; tACS stimulation of the right frontal region

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Patient aged 18 and over
• Patient with homonymous lateral hemianopia with brain injury acquired for at least 3 months and at most 10 years after ischemic stroke, cerebral hematoma
• Patient able to understand French both orally and in writing
• Patient giving free, informed and written consent
• Absence of a neurological disease interfering with the passing of tests
• Patients subject to a legal protection measure (safeguarding of justice, guardianship and trusteeship, protected adults)
• Contraindication of tACS and / or magnetic resonance imaging (pacemaker or implantable defibrillator, intracranial electrodes or other intracranial implant, cranial vault anomalies facing stimulation electrodes (plates, prostheses, uncovered skull)
• Pregnant women and nursing mothers
• Recruitment in other interventional studies for the duration of the participation.
• Non-affiliation to a social security scheme (excluding AME) or non-beneficiary of such a scheme
• Healthy Subject 18 years and older
• Healthy subject able to understand French both orally and in writing
• Healthy subject who has given free and informed consent and writes
• Contraindication to magnetic resonance imaging (pacemaker or implantable defibrillator, intracranial electrodes or other intracranial implant, abnormalities of the cranial vault opposite stimulation electrodes (plates, prostheses, uncovered skull)
• Recruitment in other interventional studies for the duration of the participation.

Sponsors & Collaborators

• Assistance Publique - Hôpitaux de Paris: lead

Study Sites (1)

GH Pitié Salpêtrière

Paris, 75013, France

Location

Related Publications (7)

• Sahraie A. Induced visual sensitivity changes in chronic hemianopia. Curr Opin Neurol. 2007 Dec;20(6):661-6. doi: 10.1097/WCO.0b013e3282f1c70f.

  PMID: 17992086 BACKGROUND

• Schuett S, Dauner R, Zihl J. Line bisection in unilateral homonymous visual field defects. Cortex. 2011 Jan;47(1):47-52. doi: 10.1016/j.cortex.2010.01.008. Epub 2010 Jan 28.

  PMID: 20172510 BACKGROUND

• Sergeeva EG, Henrich-Noack P, Bola M, Sabel BA. Brain-state-dependent non-invasive brain stimulation and functional priming: a hypothesis. Front Hum Neurosci. 2014 Nov 5;8:899. doi: 10.3389/fnhum.2014.00899. eCollection 2014. No abstract available.

  PMID: 25414662 BACKGROUND

• Sabel BA, Fedorov AB, Naue N, Borrmann A, Herrmann C, Gall C. Non-invasive alternating current stimulation improves vision in optic neuropathy. Restor Neurol Neurosci. 2011;29(6):493-505. doi: 10.3233/RNN-2011-0624.

  PMID: 22124039 BACKGROUND

• Zaehle T, Rach S, Herrmann CS. Transcranial alternating current stimulation enhances individual alpha activity in human EEG. PLoS One. 2010 Nov 1;5(11):e13766. doi: 10.1371/journal.pone.0013766.

  PMID: 21072168 BACKGROUND

• Helfrich RF, Knepper H, Nolte G, Struber D, Rach S, Herrmann CS, Schneider TR, Engel AK. Selective modulation of interhemispheric functional connectivity by HD-tACS shapes perception. PLoS Biol. 2014 Dec 30;12(12):e1002031. doi: 10.1371/journal.pbio.1002031. eCollection 2014 Dec.

  PMID: 25549264 BACKGROUND

• Alekseichuk I, Diers K, Paulus W, Antal A. Transcranial electrical stimulation of the occipital cortex during visual perception modifies the magnitude of BOLD activity: A combined tES-fMRI approach. Neuroimage. 2016 Oct 15;140:110-7. doi: 10.1016/j.neuroimage.2015.11.034. Epub 2015 Nov 23.

  PMID: 26608246 BACKGROUND

MeSH Terms

Conditions

Hemianopsia

Condition Hierarchy (Ancestors)

Vision Disorders; Sensation Disorders; Neurologic Manifestations; Nervous System Diseases; Blindness; Eye Diseases; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

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: July 25, 2019
• First Posted: August 2, 2019
• Study Start: December 22, 2020
• Primary Completion: April 3, 2025
• Study Completion: April 3, 2025
• Last Updated: May 8, 2025

Record last verified: 2025-05

Locations

FR (1)