Neural, Behavioural, and Clinical Effects of tDCS in PDOC; Feasibility Study (RAINDROP)
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ClinicalTrials.gov Identifier: NCT04248946 |
Recruitment Status :
Not yet recruiting
First Posted : January 30, 2020
Last Update Posted : May 3, 2021
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Condition or disease | Intervention/treatment | Phase |
---|---|---|
Consciousness Disorder Brain Injuries Vegetative State Minimally Conscious State | Other: Transcranial direct current stimulation | Not Applicable |
Study Type : | Interventional (Clinical Trial) |
Estimated Enrollment : | 15 participants |
Allocation: | Non-Randomized |
Intervention Model: | Crossover Assignment |
Intervention Model Description: | This is a double-blind randomised crossover feasibility study of tDCS in a small cohort of PDOC individuals. The study is divided into two streams to accommodate differences in the resources available across recruitment sites: 1. MRI stream, which will include MRI and electrophysiology assessments; this is available to patients receiving care at the Wellington Hospital in London only. 2. Bedside stream, which will include electrophysiology assessments only, available to patients in specialist units at NHS (National Health Service) and non-NHS sites |
Masking: | Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor) |
Masking Description: | In the MRI stream all participants will receive anodal, cathodal, and sham (placebo) tDCS sessions in a randomised order. In the Bedside stream participants will receive active tDCS (either anodal or cathodal) and sham sessions also in a randomised order. A researcher not involved in data collection or analyses will programme the stimulator to deliver the specific polarity needed in each session in a double-blind manner. Sham tDCS will be delivered according to published guidelines: this mimics the physical sensations of active stimulation but does not have a neuromodulatory effect |
Primary Purpose: | Basic Science |
Official Title: | Sham-controlled, Double-blind, Randomised Crossover Study of the Neural, Behavioural, and Clinical Effects of Transcranial Direct Current Stimulation in Patients With a Prolonged Disorder of Consciousness; Feasibility Study |
Estimated Study Start Date : | July 2021 |
Estimated Primary Completion Date : | August 2022 |
Estimated Study Completion Date : | August 2022 |

Arm | Intervention/treatment |
---|---|
Experimental: MRI stream
In this stream all patients receive 2 experimental interventions (anodal tDCS and cathodal tDCS) and a sham intervention (sham tDCS). These are delivered in randomised order, ensuring a balanced distribution of participants across possible orders. They will receive 5 sessions per condition (on consecutive days), for a total of 15 sessions. I. Anodal, cathodal, sham II. Anodal, sham, cathodal III. Cathodal, anodal, sham IV. Cathodal, sham, anodal V. Sham, anodal, cathodal VI. Sham, cathodal, anodal |
Other: Transcranial direct current stimulation
tDCS alters neural excitability in a polarity-specific manner via a weak direct electric current delivered through electrodes placed on the scalp. There are 3 types of stimulation: anodal, cathodal, and sham. In anodal tDCS, the positive electrode is placed over the target brain area to increase neuronal excitability. In cathodal tDCS, the negative electrode is placed over the target brain area to decrease neuronal excitability. Sham tDCS emulates the physical sensations of active (anodal/cathodal) tDCS but current is only delivered for a short period of time and is not enough to cause any neuromodulations
Other Name: tDCS |
Experimental: Bedside stream
In this stream all patients receive 1 experimental interventions (either anodal tDCS or cathodal tDCS) and 1 sham intervention (sham tDCS). These include only 1 session per condition and are delivered in randomised order, resulting in the following possible combinations: I. Anodal, sham II. Cathodal, sham III. Sham, anodal IV. Sham, cathodal Participants will be randomly assigned to the above groups ensuring a balanced distribution of participants across them. |
Other: Transcranial direct current stimulation
tDCS alters neural excitability in a polarity-specific manner via a weak direct electric current delivered through electrodes placed on the scalp. There are 3 types of stimulation: anodal, cathodal, and sham. In anodal tDCS, the positive electrode is placed over the target brain area to increase neuronal excitability. In cathodal tDCS, the negative electrode is placed over the target brain area to decrease neuronal excitability. Sham tDCS emulates the physical sensations of active (anodal/cathodal) tDCS but current is only delivered for a short period of time and is not enough to cause any neuromodulations
Other Name: tDCS |
- Retention at end of active phase [ Time Frame: through completion of active phase of study (tDCS intervention), on average 4 weeks for bedside stream and 8 weeks for MRI stream ]percentage of participants on study at pre-specified time points counted from the start of participation in the study (i.e., first study procedure)
- Retention at 3 months [ Time Frame: 3 months after start of participation ]percentage of participants on study at pre-specified time points counted from the start of participation in the study (i.e., first study procedure). This Outcome applies to the bedside stream only
- Retention at 6 months [ Time Frame: 6 months after start of participation ]percentage of participants on study at pre-specified time points counted from the start of participation in the study (i.e., first study procedure). This Outcome applies to the bedside stream only
- Completion [ Time Frame: through completion of active phase of study (tDCS intervention), on average 4 weeks for bedside stream and 8 weeks for MRI stream ]percentage of tDCS, MRI, and electrophysiology assessments completed per polarity
- Structural MRI [ Time Frame: day 1 and day 5 of tDCS each polarity ]This will include assessments of the gross macrostructure, and microstructure of brain tissue grey matter, white matter, and cerebrospinal fluid
- Functional MRI in response to task instructions [ Time Frame: day 1 and day 5 of tDCS each polarity ]This will include assessments of the BOLD (blood oxygen level-dependent) response to characterise brain activity and connectivity during command following
- EEG power in the alpha band in response to task instructions [ Time Frame: days 1 and 4 of each polarity in the MRI stream and day 1 of each polarity in the bedside stream ]Envelope of bandpass filtered EEG data between 8-12 Hertz
- EEG power in the beta band in response to task instructions [ Time Frame: days 1 and 4 of each polarity in the MRI stream and day 1 of each polarity in the bedside stream ]Envelope of bandpass filtered EEG data between 13-30 Hertz
- EMG (electromyography) amplitude changes [ Time Frame: days 1-4 and day 2 of each polarity in the MRI and bedside streams respectively ]Changes in the amplitude of the rectified EMG signal (high-pass filtered > 50Hz) in response to instructions to move
- Coma recovery scale -revised [ Time Frame: regularly through active phase of study (baseline and outcome assessments), on average 4 weeks for bedside stream and 8 weeks for MRI stream ]clinical diagnostic scale for disorders of consciousness. Total score ranges from 0 to 23, where higher scores mean a higher level of functioning and awareness
- Glasgow Outcome Scale-extended [ Time Frame: at 3 and 6 months after start of participation ]Scale for functional outcome after brain injury. Total score ranges from 1 to 8, where higher values correspond to better outcome

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Ages Eligible for Study: | 18 Years and older (Adult, Older Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | No |
Inclusion Criteria:
- Aged 18 years or older
- Receiving care at a recruitment site, with a consensus clinical diagnosis of PDOC from any aetiology (i.e. traumatic or non-traumatic injury).
- Stable and with no need of mechanical support (i.e. respirator, etc.)
Exclusion Criteria:
- Scalp skin sores or any skin damage at the electrode sites
- Metallic implants in the face or skull
- Craniectomy or cranioplasty
- No evidence of auditory startle in clinical observations, or absent brainstem auditory evoked potentials in recent clinical history (if data available)
- MRI incompatible: metal plates incompatible with MRI scanners, pacemaker, inability to lay flat for prolonged periods of time, aneurysm clips, neurostimulators, brain/subdural electrodes, etc. (MRI stream ONLY)

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT04248946
Contact: Davinia Fernandez Espejo, PhD FHEA | 01214145534 | d.fernandez-espejo@bham.ac.uk |
United Kingdom | |
Moseley Hall Hospital | |
Birmingham, West Midlands, United Kingdom, B13 8JL | |
The Wellington Hospital | |
London, United Kingdom, NW8 9LE | |
Contact: Antonio Incisa, PhD CPsychol CSci +44 (0)20 7483 5595 Antonio.Incisa@HCAHealthcare.co.uk |
Responsible Party: | University of Birmingham |
ClinicalTrials.gov Identifier: | NCT04248946 |
Other Study ID Numbers: |
RG_18-269 |
First Posted: | January 30, 2020 Key Record Dates |
Last Update Posted: | May 3, 2021 |
Last Verified: | April 2021 |
Individual Participant Data (IPD) Sharing Statement: | |
Plan to Share IPD: | No |
Studies a U.S. FDA-regulated Drug Product: | No |
Studies a U.S. FDA-regulated Device Product: | No |
Brain Injuries Persistent Vegetative State Consciousness Disorders Brain Diseases Central Nervous System Diseases Nervous System Diseases Craniocerebral Trauma Trauma, Nervous System |
Wounds and Injuries Brain Damage, Chronic Unconsciousness Neurobehavioral Manifestations Neurologic Manifestations Neurocognitive Disorders Mental Disorders |