Investigation on the Cortical Communication System

Not Applicable

Recruiting

• Conditions: Locked-in Syndrome; Brainstem Stroke; Neuromuscular Diseases; Traumatic Brain Injury
• Interventions: Device: ECoG (electrocorticography) sensing

• Registration Number: NCT06207591
• Lead Sponsor: UMC Utrecht

Brief Summary

The goal of this clinical trial is to demonstrate communication through a brain implant in people in locked-in state, i.e. people with severe paralysis and communication problems.

The main questions it aims to answer are efficient and stable control of Brain-Computer interface (BCI) functions for communication with attempted hand movements and operation of a keyword-based speech BCI.

Participants will be implanted with four electrode grids, with in total 128 electrodes, on the surface of the brain and a connector on the skull. Participation includes visits of researchers for recording and training at home, 2-3 times per week for one year. Extension of participation after one year is possible.

If successful, the participant will be able to use the BCI at home independently, without the presence of a researcher.

Detailed Description

Locked-In Syndrome (LIS) is a neurological condition in which communication is impossible, or profoundly impaired, due to loss of speech and other motor functions, while cognition is intact. The most distressing aspect of LIS is the inability to initiate and sustain communication. Existing assistive technologies (ATs) fall short of a remedy. An effective brain-computer interface (BCI) for communication would dramatically improve quality of life for people with LIS. Electrocorticography (ECoG) with non-penetrating subdural electrodes is a promising implantable approach for BCI. In this study, the "CortiCom system" (which stands for Cortical Communication) wil be used. This system combines an implantable assembly, consisting of four small high-density (HD) ECoG grids on the hand and speech areas of the motor cortex, totalling 128-channels, and a transcutaneous pedestal connector, with an external data acquisition system. With the CortiCom system the overall hypothesis will be tested that broader and more densely spaced ECoG electrodes can better tap into the spatial detail of the organization of the sensorimotor cortex in order to expand BCI function and restore meaningful communication in LIS. Specifically, the CortiCom system will substantially increase the number and density of electrodes recording from the brain to determine whether more sophisticated control and communication can be achieved with more comprehensive and detailed spatial sampling of representations for movements of the hand/arm and of speech articulators. Clinically meaningful outcomes for people with LIS include rapid reestablishment, and stable maintenance of communication, at minimum consisting of a caregiver call-button and menu selections.

Objective:

Primary Objective 1: Demonstrate efficient and stable control of essential BCI functions (initiate BCI, call caregiver, and menu selections). Primary Objective 2: Demonstrate efficient and stable operation of a keyword-based speech BCI.

Intervention:

Participants will be implanted with an assembly consisting of HD-ECoG electrode grids over the sensorimotor cortex and a transcutaneous pedestal connector. The assembly will be connected with an external data acquisition system during recordings. During recordings, feedback about the neural signals is given via a visual display and participants are trained to employ the neural signals for fast brain-based communication. Upon adequate performance, participants can independently (i.e., without researcher involvement) train with and use the system at home for validation of performance and usability. After implantation, participation has a duration of 1 year, with a possibility of extension.

Study Timeline

• Study First Submitted: 2023-12-01
• Study Start: 2023-12-15
• Status Verified: 2024-01
• Study First Submitted QC: 2024-01-12
• Last Update Submitted: 2024-01-12
• Study First Posted: 2024-01-17
• Last Update Posted: 2024-01-17
• Primary Completion: 2026-10
• Study Completion: 2027-10

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 2

Inclusion Criteria

• 18-70 years
• Clinical diagnosis of locked-in state caused by traumatic brain injury, brainstem stroke, neurodegenerative disease, neuromuscular disease or another cause
• Complete or incomplete tetraplegia (quadriplegia) or tetraparesis (quadriparesis)
• Motor-related speech impairment (dysarthria or anarthria)
• Either receiving tracheostomy invasive ventilation, or having a stable and adequate respiratory situation without respiratory support, allowing for safe intubation, mechanical ventilation and detubation during surgery according to the involved clinicians, and, if relevant (e.g., in case of a progressive condition), in combination with a confirmed desire to receive tracheostomy invasive ventilation when that becomes necessary
• Meeting surgical safety criteria, including surgical clearance by the study physicians
• Meeting (neuro)psychological evaluation criteria
• Ability to communicate reliably, such as through eye movement
• Willingness and ability to provide informed consent
• Lives within reasonable distance from University Medical Center Utrecht
• Participant consents to the study and still wishes to participate at the time of the study
• Vision and hearing largely intact

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Exclusion Criteria

• Performance on formal neuropsychological testing that indicates a significant current or recent psychiatric disorder, cognitive or behavioral impairment, that would interfere with obtaining informed consent or fully participating in study activities
• Medical conditions contraindicating surgery of a chronically implanted device or that could interfere with study participation (for example active infections, unexplained fever, existing scalp lesions or skin breakdown, osteomyelitis, hepatitis, any autoimmune disease/disorder, epilepsy, skin disorders causing excessive skin sloughing or poor wound healing, cranioplasty, significant cardiovascular, metabolic, or renal impairments, chronic oral or intravenous use of steroids or immunosuppressive therapy, active cancer within the past year or requires chemotherapy, uncontrolled autonomic dysreflexia within the past 3 months, hydrocephalus with or without an implanted ventricular shunt or a medical contraindication to stop anti-coagulant medications during surgery)
• Presence of pre-surgical findings in anatomical, functional, and/or vascular neuroimaging that makes achieving implant locations too challenging or incompatible with desired risk levels
• Inability to undergo MRI for pre-implantation evaluation, for example due to the presence of implanted devices that are incompatible with MRI, which may include pacemakers, cardiac defibrillators, spinal cord or vagal nerve stimulators, deep brain stimulators, and cochlear implants
• Anticipated need for MRI after implantation of the CortiCom assembly

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Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
ECoG (electrocorticography) sensing	ECoG (electrocorticography) sensing	Use implantable ECoG-based Brain Computer interface to control assistive technology

Primary Outcome Measures

Name	Time	Method
Usability of the BCI system - subjective workload NASA-TLX	1 year	Subjective Workload: National Aeronautics and Space Administration-Task Load Index Scale: 21 point Likert-type scale. Lower numbers are better.
Usability of the BCI system - user satisfaction QUEST	1 year	User Satisfaction: Quebec User Evaluation of Satisfaction with assistive Technology.; Likert-type scale: Extremely dissatisfied - Dissatisfied - Slightly satisfied - Satisfied - Extremely satisfied. Extremely Satisfied is the best result.
Degrees of Freedom of BCI Control.	1 year	the number of different commands that are successfully decoded, or the size of the decoded vocabulary
Usability of the BCI system - speed	1 year	Speed characters or keywords per minute
Usability of the BCI system - user satisfaction PIADS	1 year	User Satisfaction: Psychosocial impact of assistive devices scale. Likert-type scale -3, -2, -1, 0, 1, 2, 3. 3 is best result.
Usability of the BCI system - subjective workload VAS	1 year	Subjective Workload: Visual Analogue Scale Continuous scale: Little to no effort (0) - Much effort (5). Lower numbers are better.
Usability of the BCI system - Accuracy	1 year	Accuracy: \>80% sensitivity (true positive rate) for 1-command control, and 90% sensitivity and 80% classification accuracy (distinguishing between the six classes) for 6-command control
Usability of the BCI system - validation	1 year	Validation: Questionnaire to evaluate user satisfaction and ease of use of the home use software.; Likert-type scale: fully disagree - disagree - neither agree or disagree - agree - fully agree - not applicable. Fully agree is the best result.

Secondary Outcome Measures

Name	Time	Method
Independent use of BCI	2 years	Longitudinal data of independent use per day. The best result is 24h use. The data are fitted to determine trends and variance, both within 24 hrs to detect a possible circadian pattern and over weeks, to see increase or decrease of the hours of independent use.
Stability of BCI performance (modulation)	2 years	Longitudinal data of the 24-hour cycle after implantation of the task-related modulation in power (correlation in r2). The data are fitted to determine trends and variance, over weeks, to determine improvement or deterioration of modulation.
Stability of BCI performance (performance)	2 years	Longitudinal data of the 24-hour cycle after implantation of the BCI performance (task accuracy). The data are fitted to determine trends and variance, both within 24 hrs to detect a possible circadian pattern and over weeks, to see improvement or deterioration of accuracy.
Stability of BCI performance (signal)	2 years	Longitudinal data of the 24-hour cycle after implantation of the raw power (after wavelet transform, in arbitrary units). The data are fitted to determine trends and variance, both within 24 hrs to detect a possible circadian pattern and over weeks, to determine improvement or deterioration of signal amplitude.
Stability of BCI performance (electrode-tissue interaction)	2 years	Longitudinal data of the 24-hour cycle after implantation of the impedance (in Ω). The data are fitted to determine trends and variance, over weeks, to determine improvement or deterioration of electrode-tissue interaction.

Trial Locations

Locations (1)

University Medical Center; 🇳🇱 Utrecht, Netherlands