HemianopsiaHEMIANOTACSNCT04043689
Therapeutic Effects of Transcranial Alternative Current Stimulation (tACS) in Chronic Post Stroke Hemianopia
A study testing tACS (transcranial Alternate Current Stimulation) in people with Hemianopsia, run by Assistance Publique - Hôpitaux de Paris at 1 site in France.
Trial 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. Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Hemianopsia
- What is being tested?
- tACS (transcranial Alternate Current Stimulation)
- Type of treatment
- Medical device
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 43 participants
- Where
- 1 siteFrance
- Study dates
- 22 Dec 2020to 3 Apr 2025
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- 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
- Non-inclusion criteria :
Show all 22Show fewer
- Patients subject to a legal protection measure (safeguarding of justice, guardianship and trusteeship, protected adults)
- Pre-existing severe ophthalmological disorders, visual field disorders visual field disorders, monocular visual acuity less than 5/10, severe oculomotor disorders (post-stroke ophthalmological consultation less than at the time of inclusion)
- 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 participants inclusion criteria are the following:
- 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
- Healthy participants non-inclusion criteria are the following:
- Severe neurological, psychiatric, physical, or ophthalmological disorders (binocular visual acuity less than 5/10, ophthalmological consultation less than one year old at the time of inclusion) that interfere with the normal performance of tests and study tasks
- 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.
- Pregnant women and nursing mothers
- Non-affiliation to a social security scheme (excluding AME) or non-beneficiary of such a scheme
Who cannot join
None listed.
Trial locations and contacts
1 site in 1 country.
About this study
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.
Read more
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.
Read the detailed description
Background:
Focusing on low-level perceptual activities, and robust, controlled explorations with medium-sized cohorts, several studies have shown tACS effects related to oscillatory activity and inter-regional synchrony.
For example, in healthy subjects, occipital tACS showed an increase in posterior alpha power following tACS alpha (10-14 Hz). At higher frequencies, the 60 Hz tACS showed a sustained reduction in visual contrast sensitivity threshold . Two studies in 2014 have also shown following 40 Hz tACS stimulation of occipital or parietal brain regions in healthy humans, sustained dependent on synchrony of posterior interhemispheric gamma band networks, and modulation effects of moving target perception Very recently, a 10 Hz occipital tACS stimulation study coupled with functional magnetic resonance Imaging recording (fMRI) showed diffuse effects likely to indicate occipito-parieto-temporal synchronization during the delayed phase of effects.
Among patients' trials, an observational study of uncontrolled occipital tACS in patients with optic nerve lesions showed improved visual acuity and visual field size, accompanied by an increase in power and of occipital alpha synchrony by targeting periorbital regions; More recently, a double-blind, multicenter, controlled trial in patients with optic nerve lesions showed, with daily transorbital tACS sessions lasting 10 weeks, a sustained (2.5%) increase in visual field size versus stimulation placebo.
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 study 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. This intervention will be compared 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.
The overall goal of this project is to modulate visual perception in patients with HH in the chronic phase using transcranial AC stimulation. The study aim is to evaluate the behavioral effects of tACS stimulation of the right fronto-parietal network (FEF-IPS) and the occipital and parieto-occipital region (V1-IPS), contralateral to the lesion, on visual perception in static and kinetic perimetry. The effects of stimulation of these two targets on brain activity by electrophysiology (EEG) will be quantified. The hypothesis is that the tACS, by increasing the functional connectivity (phase synchronism at the frequency delivered during the stimulation), will make it possible to modulate the threshold of visual perception.
Specifically, the hypothesis is that a single session of 30 Hz tACS stimulation of the right frontal cortex (around the right FEF) will increase fronto-parietal synchrony within the right hemisphere of patients with lesions acquired brain responsible for chronic HH, thus improving the static and kinetic visual field in the first 30 minutes post-stimulation. The investigator team also hypothesize that a single session of tACS stimulation on the occipital and posterior parietal cortex contralateral to the lesion (around the V1 region) of patients with acquired brain lesions responsible for chronic HH will improve the visual field in the first 30 minutes post-stimulation, but this improvement will be less compared to the improvement caused by the stimulation of the right FEF, which could be accompanied by a temporary decrease in the visual perception of the targets on the healthy visual hemi-field.
Methods:
Monocentric comparative randomized controlled, cross-over and blinded study, Major population, acquired brain lesion responsible for homonymous hemianopia, chronic phase of cerebrovascular accident (between 3 months and 10 years of evolution) and cohort healthy subjects not treated with tACS to obtain normative data from visual fields, neuroimaging (MRI) and electroencephalography (EEG)
- Each patient or each healthy volunteer will have an inclusion visit including visual static and kinetic perimetry, EEG recordings, cognitive tests, questionnaire and brain MRI.
- Then, each patient will have 3 visits, including a first evaluation period (perimetry, EEG and reading tests) then a stimulation session (right frontal active tACS or contralesional occipito-parietal active tACS, or placebo tACS) then a second evaluation time (EEG, perimetry , and reading tests)
Discussion:
The investigator team expect an immediate and significant increase in visual field size and improved visual detection capabilities of patients treated with active tACS stimulation on the right frontal region (FEF) and / or contralateral occipital region (V1-IPS) lesion
The project will contribute to the development of an innovative treatment to improve the quality of life of HH brain-injured patients, lacking effective treatment options to date.
TACS is an easily accessible and easily applicable technique in large-scale clinical practice. Coupled with EEG monitoring, it is the only one that allows efficient and safe manipulation of oscillatory activity and interregional synchronicity.
Interest in these new methods of non-invasive brain stimulation guiding brain plasticity, in stroke (130,000 new cases / year) or head trauma is very important. The scientific, clinical and technological implications are major.
- Conditions
- Hemianopsia
- Being tested
- tACS (transcranial Alternate Current Stimulation)
- Medical subject headings
- Hemianopsia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
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
| Study group | Role | What they receive |
|---|---|---|
| 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. Receives: 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. Receives: 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. Receives: Device: tACS (transcranial Alternate Current Stimulation) |
What is being measured
The primary outcome is the main question the study is designed to answer.
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
Measured: Immediately after the intervention
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted2 Aug 2019
- Study start22 Dec 2020
- Primary completion3 Apr 2025
- Study completion3 Apr 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (7)Papers the sponsor has linked to this study.
- Other trials for HemianopsiaStudies of the same condition, open and under way.
- More trials run by Assistance Publique - Hôpitaux de ParisThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Triple blind
- Who is masked
- Participant, Investigator, Outcomes assessor
- Enrolment
- 43 participants (actual)
Sponsor and investigators
- Lead sponsor
- Assistance Publique - Hôpitaux de Paris
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04043689
- Sponsor's protocol ID
- APHP 190051
- Other IDs
- 2019-A00501-56
- Acronym
- HEMIANOTACS
- Status last verified
- May 2025
- First submitted
- 25 Jul 2019
- Last updated
- 8 May 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Publications
Sahraie A. Induced visual sensitivity changes in chronic hemianopia. Curr Opin Neurol. 2007 Dec;20(6):661-6. doi: 10.1097/WCO.0b013e3282f1c70f.
PubMed 17992086Schuett 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.
PubMed 20172510Sergeeva 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.
PubMed 25414662Sabel 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.
PubMed 22124039Zaehle 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.
PubMed 21072168Helfrich 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.
PubMed 25549264Alekseichuk 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.
PubMed 26608246
Study at a glance
From the registry record, last updated by the sponsor on 8 May 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Therapeutic Effects of Transcranial Alternative Current Stimulation (tACS) in Chronic Post Stroke Hemianopia
- ClinicalTrials.gov ID
- NCT04043689
- Acronym / sponsor ID
- HEMIANOTACS / APHP 190051
- Conditions
- Hemianopsia
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 43 participants (actual)
- Lead sponsor
- Assistance Publique - Hôpitaux de ParisUniversity, hospital or other
- Study start
- 22 Dec 2020 (actual)
- Primary completion
- 3 Apr 2025 (actual)
- Study completion
- 3 Apr 2025 (actual)
- First posted
- 2 Aug 2019 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Detailed description
Background:
Focusing on low-level perceptual activities, and robust, controlled explorations with medium-sized cohorts, several studies have shown tACS effects related to oscillatory activity and inter-regional synchrony.
For example, in healthy subjects, occipital tACS showed an increase in posterior alpha power following tACS alpha (10-14 Hz). At higher frequencies, the 60 Hz tACS showed a sustained reduction in visual contrast sensitivity threshold . Two studies in 2014 have also shown following 40 Hz tACS stimulation of occipital or parietal brain regions in healthy humans, sustained dependent on synchrony of posterior interhemispheric gamma band networks, and modulation effects of moving target perception Very recently, a 10 Hz occipital tACS stimulation study coupled with functional magnetic resonance Imaging recording (fMRI) showed diffuse effects likely to indicate occipito-parieto-temporal synchronization during the delayed phase of effects.
Among patients' trials, an observational study of uncontrolled occipital tACS in patients with optic nerve lesions showed improved visual acuity and visual field size, accompanied by an increase in power and of occipital alpha synchrony by targeting periorbital regions; More recently, a double-blind, multicenter, controlled trial in patients with optic nerve lesions showed, with daily transorbital tACS sessions lasting 10 weeks, a sustained (2.5%) increase in visual field size versus stimulation placebo.
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 study 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. This intervention will be compared 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.
The overall goal of this project is to modulate visual perception in patients with HH in the chronic phase using transcranial AC stimulation. The study aim is to evaluate the behavioral effects of tACS stimulation of the right fronto-parietal network (FEF-IPS) and the occipital and parieto-occipital region (V1-IPS), contralateral to the lesion, on visual perception in static and kinetic perimetry. The effects of stimulation of these two targets on brain activity by electrophysiology (EEG) will be quantified. The hypothesis is that the tACS, by increasing the functional connectivity (phase synchronism at the frequency delivered during the stimulation), will make it possible to modulate the threshold of visual perception.
Specifically, the hypothesis is that a single session of 30 Hz tACS stimulation of the right frontal cortex (around the right FEF) will increase fronto-parietal synchrony within the right hemisphere of patients with lesions acquired brain responsible for chronic HH, thus improving the static and kinetic visual field in the first 30 minutes post-stimulation. The investigator team also hypothesize that a single session of tACS stimulation on the occipital and posterior parietal cortex contralateral to the lesion (around the V1 region) of patients with acquired brain lesions responsible for chronic HH will improve the visual field in the first 30 minutes post-stimulation, but this improvement will be less compared to the improvement caused by the stimulation of the right FEF, which could be accompanied by a temporary decrease in the visual perception of the targets on the healthy visual hemi-field.
Methods:
Monocentric comparative randomized controlled, cross-over and blinded study, Major population, acquired brain lesion responsible for homonymous hemianopia, chronic phase of cerebrovascular accident (between 3 months and 10 years of evolution) and cohort healthy subjects not treated with tACS to obtain normative data from visual fields, neuroimaging (MRI) and electroencephalography (EEG)
- Each patient or each healthy volunteer will have an inclusion visit including visual static and kinetic perimetry, EEG recordings, cognitive tests, questionnaire and brain MRI.
- Then, each patient will have 3 visits, including a first evaluation period (perimetry, EEG and reading tests) then a stimulation session (right frontal active tACS or contralesional occipito-parietal active tACS, or placebo tACS) then a second evaluation time (EEG, perimetry , and reading tests)
Discussion:
The investigator team expect an immediate and significant increase in visual field size and improved visual detection capabilities of patients treated with active tACS stimulation on the right frontal region (FEF) and / or contralateral occipital region (V1-IPS) lesion
The project will contribute to the development of an innovative treatment to improve the quality of life of HH brain-injured patients, lacking effective treatment options to date.
TACS is an easily accessible and easily applicable technique in large-scale clinical practice. Coupled with EEG monitoring, it is the only one that allows efficient and safe manipulation of oscillatory activity and interregional synchronicity.
Interest in these new methods of non-invasive brain stimulation guiding brain plasticity, in stroke (130,000 new cases / year) or head trauma is very important. The scientific, clinical and technological implications are major.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Triple blind (participant, investigator, outcomes assessor)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| tACS stimulation of the right frontal region | Active comparator | Device: tACS (transcranial Alternate Current Stimulation)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. |
| tACS stimulation of the occipito-parietal region | Active comparator | Device: tACS (transcranial Alternate Current Stimulation)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. |
| TACS stimulation of the right frontal (FEF) | Sham comparator | Device: tACS (transcranial Alternate Current Stimulation). 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. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (22 listed)
- 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
Key exclusion criteria (0 listed)
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| tACS (transcranial Alternate Current Stimulation)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 | Device | TACS stimulation of the right frontal (FEF), tACS stimulation of the occipito-parietal region, tACS stimulation of the right frontal region |
Primary outcome
To evaluate the immediate effect of a single tACS session on the static visual field size of patients with chronic phase HH
Time frame: Immediately after the intervention
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
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 8 May 2025.
- Background: PubMed 17992086Sahraie A. Induced visual sensitivity changes in chronic hemianopia. Curr Opin Neurol. 2007 Dec;20(6):661-6. doi: 10.1097/WCO.0b013e3282f1c70f.
- Background: PubMed 20172510Schuett 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.
- Background: PubMed 25414662Sergeeva 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.
- Background: PubMed 22124039Sabel 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.
- Background: PubMed 21072168Zaehle 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.
- Background: PubMed 25549264Helfrich 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.
- Background: PubMed 26608246Alekseichuk 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.
- Individual participant dataSharing planned: Undecided
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing tACS (transcranial Alternate Current Stimulation) in people with Hemianopsia, run by Assistance Publique - Hôpitaux de Paris at 1 site in France.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 22 inclusion and 0 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 8 May 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in France. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
To evaluate the immediate effect of a single tACS session on the static visual field size of patients with chronic phase HH (time frame: Immediately after the intervention). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT04043689, which also lists 7 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 8 May 2025.