Transcranial Direct Current Stimulation Effects in Patients With Chronic Consciousness Disorders

Study Overview
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Brief Summary
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Chronic consciousness disorders have high level of impact on public health and its costs.

Detailed Description
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Consciousness disorders have high impact on society and national health system. One of these disorders is vegetative condition in which, as in coma, there isn't any self or environmental consciousness but there is alertness, whereas in minimal state of consciousness at least part of awareness is conserved. In Emilia Romagna region about 80 people per million of inhabitants are hospitalized after cerebral damage, and after discharge about 1/5 of patients are stabilized in a consciousness disorder. The diagnosis of these disorders is based on neurobehavioural tests, for example JFK Coma Recovery Scale Revised (CRS-R). In these patients recovery of state of consciousness is one of the main challenges. There are very little evidences about treatment, it has been proposed the use of therapies that could modulate central nervous system activity, like specific drugs, neuroimaging and neuromodulation techniques such as transcranial magnetic stimulation and repetitive transcranial current stimulation. A non invasive neuromodulation technique is transcranial direct current stimulation (tDCS) which can modulate cortical excitability: cathodic current reduces excitability whereas anodic current increases it. In conclusion, tDCS is an easy technique to use, it's not invasive and it's an efficient tool for the modulation of cortical excitability that demonstrated reliable results in healthy subjects. As the tDCS can modulate cortical excitability it is likely that the combination of this stimulation tool with transcranial magnetic stimulation for the registration of cortical excitability could give important information about cerebral damage in patients with consciousness disorders and to test new treatments. It is also likely that the modification of cortical excitability could induce neurobehavioural changes.

Official Title
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Transcranial Direct Current Stimulation (tDCS) Effects in Patients With Chronic Consciousness Disorders

Conditions
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TBI, Minimally Conscious State

Intervention / Treatment
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* Device: real-tDCS


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: males and females aged >18 years old and <70 years old diagnosis of disorders of consciousness classified as MCS according to criteria of American Academy of Neurology1. traumatic etiology (>12 months after the acute injury) Exclusion Criteria: contraindications to single pulse TMS (TMS will be used to measure cortical excitability) such as metal head implants, history of seizures, metal in the head, implanted brain medical devices. contraindications to tDCS such as metal in the head, implanted brain medical devices.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 70 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: real-tDCS<br>Participants will receive tDCS over the primary motor cortex bilaterally (M1). The excitability-enhancing anode electrode (saline-soaked sponge electrode - 16cm2) will be placed over the primary motor cortex, C3 and C4 (10/20 international EEG system). The excitability-diminishing cathode electrode will be placed over the supraorbital area. We will use the following stimulation parameters: intensity of 2 milliampere and for 40 minutes (10 consecutive sessions). | Device: real-tDCS<br>* Participants will receive tDCS over the primary motor cortex bilaterally (M1). The excitability-enhancing anode electrode (saline-soaked sponge electrode - 16cm2) will be placed over the primary motor cortex, C3 and C4 (10/20 international EEG system). The excitability-diminishing cathode electrode will be placed over the supraorbital area. We will use the following stimulation parameters: intensity of 2 milliampere and for 40 minutes (10 consecutive sessions).<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Coma Recovery Scale Revised (CRS-R) | behavioural scale (visual, auditory, motor, verbal, communication, arousal) | Change measures (weeks: -2,0,1,2,4) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| single-pulse transcranial magnetic stimulation (TMS) | cortical excitability measures | Change measures (weeks: -2,0,1,2,4) | 
| functional near infrared spectroscopy (fNIRS) | cerebral perfusion | Change measures (weeks: -2,0,1,2,4) | 
| electroencephalography (EEG) | To assess if, after tDCS administration, MCS patients could show: electroencephalographic pattern modifications | Change measures (weeks: -2,0,1,2,4) | 
| Circulating Biomarkers | blood biomarker levels modifications | Change measures (weeks: -2,0,1,2,4) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Minimally Conscious State, tDCS