Investigation on the Cortical Communication System

Inclusion Criteria: * 18-70 years * Clinical diagnosis of locked-in state state or likelihood of soon progressing into LIS (within an estimated 2 years), caused by traumatic brain injury, brainstem stroke, neurodegenerative disease, neuromuscular disease or another cause * • Current or imminent complete or incomplete tetraplegia (quadriplegia) or tetraparesis (quadriparesis) * • Current or imminent 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 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