The main questions this study aims to answer are: Can low-intensity FUS neuromodulation be safely and feasibly administered to the bilateral central thalamus in patients with disorders of consciousness (DoC)? Does FUS neuromodulation result in short-term improvements in arousal or behavioral responsiveness? Does FUS neuromodulation produce measurable changes in neural activity on EEG and/or fMRI? Participants will: Receive two sessions of low-intensity FUS neuromodulation, spaced four weeks apart, plus or minus one week. Undergo pre- and post-treatment assessments, including planning CT, MRI/fMRI, EEG, and standardized clinical scales such as the Coma Recovery Scale-Revised (CRS-R) and Glasgow Coma Scale (GCS). Be continuously monitored for safety during and after each FUS treatment. Complete follow-up imaging and clinical assessments approximately 2 weeks after each FUS session, 12 weeks after the second treatment, and at 12 months post-injury when clinically feasible.
This is a prospective, single-center, single-arm, open-label pilot clinical trial. Approximately 10-15 participants are expected to be enrolled. Each participant will receive two sessions of low-intensity focused ultrasound (FUS) neuromodulation targeting the bilateral central thalamus, spaced four weeks apart, plus or minus one week. Participants will be followed for safety, clinical, imaging, and neurophysiological assessments, including follow-up through 12 weeks after the second treatment and, when clinically feasible, at 12 months post-injury.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
TREATMENT
Masking
NONE
Enrollment
10
Participants will receive MR-guided focused ultrasound neuromodulation using the Next Generation Dome Helmet (NGDH). Each participant will undergo two treatment sessions spaced four weeks apart. MRI and CT imaging will be used to guide targeting of the bilateral centromedian/parafascicular nuclei of the thalamus. Continuous monitoring will be performed during each session, and follow-up clinical, EEG, and MRI assessments will be conducted to evaluate safety, feasibility, and preliminary effects.
Sunnybrook Health Sciences Centre
Toronto, Ontario, Canada
RECRUITINGFeasibility of Bilateral Central Thalamic FUS Neuromodulation
Feasibility will be defined as the proportion of enrolled participants who complete both focused ultrasound (FUS) neuromodulation sessions without protocol deviation or occurrence of a serious adverse event (SAE) related to the procedure.
Time frame: Assessed at Screening/Baseline, Treatment 1, Mid-treatment assessment (2 weeks after Treatment 1), Treatment 2 (4 weeks after Treatment 1), 2-week follow-up (2 weeks after each treatment), 12 weeks after Treatment 2, and 1-year follow-up.
Safety of FUS Next Generation Dome Helmet (NGDH) to Perform Neuromodulation in Patients with Disorders of Consciousness
Safety will be assessed by the frequency, type, and severity of adverse events (AEs) and serious adverse events (SAEs) following FUS treatment. Events of interest include seizures, autonomic instability, new focal neurological deficits, clinical deterioration, or structural abnormalities detected on post-treatment MRI.
Time frame: Assessed at Screening/Baseline, Treatment 1, Mid-treatment assessment (2 weeks after Treatment 1), Treatment 2 (4 weeks after Treatment 1), 2-week follow-up (2 weeks after each treatment), 12 weeks after Treatment 2, and 1-year follow-up.
Change in Behavioral Responsiveness (Coma Recovery Scale-Revised, CRS-R)
The Coma Recovery Scale-Revised (CRS-R) is a standardized behavioral assessment used to measure level of consciousness in patients with disorders of consciousness. The CRS-R consists of 6 subscales (Auditory, Visual, Motor, Oromotor/Verbal, Communication, and Arousal) that evaluate reproducible signs of awareness. Total scores range from 0 to 23, with higher scores indicating greater behavioral responsiveness and higher levels of consciousness.
Time frame: Assessed at Baseline, Treatment 1, Mid-treatment assessment (2 weeks after Treatment 1), Treatment 2 (4 weeks after Treatment 1), 2-week follow-up (2 weeks after each treatment), 12 weeks after Treatment 2, and 1-year follow-up.
Change in Glasgow Coma Scale (GCS)
The Glasgow Coma Scale (GCS) is a standardized clinical tool used to assess a patient's level of consciousness, particularly after brain injury. It evaluates three components of responsiveness: eye opening, verbal response, and motor response. Each component is scored individually and then summed to produce a total score ranging from 3 to 15. Higher scores indicate better neurological function and greater levels of consciousness, while lower scores reflect more severe impairment.
Time frame: Assessed at Baseline, Treatment 1, Mid-treatment assessment (2 weeks after Treatment 1), Treatment 2 (4 weeks after Treatment 1), 2-week follow-up (2 weeks after each treatment), 12 weeks after Treatment 2, and 1-year follow-up.
Change in Rancho Los Amigos Scale Level
The Rancho Los Amigos Scale (also known as the Rancho Los Amigos Levels of Cognitive Functioning Scale) is an 8-level clinical scale used to assess cognitive recovery and behavioral responsiveness following severe brain injury. The scale ranges from Level I (No Response) to Level VIII (Purposeful and Appropriate Response). Higher levels indicate greater cognitive functioning, improved awareness, and more appropriate and consistent behavioral responses. Only participants who scored 23 on CRS-R will complete The Rancho Los Amigos Scale.
Time frame: Assessed at Baseline, Treatment 1, Mid-treatment assessment (2 weeks after Treatment 1), Treatment 2 (4 weeks after Treatment 1), 2-week follow-up (2 weeks after each treatment), 12 weeks after Treatment 2, and 1-year follow-up.
Change in EEG Measures of Neural Activity
Electroencephalography (EEG) will be used to assess changes in neural activity before and after focused ultrasound (FUS) neuromodulation. EEG measures will include spectral power (frequency band power across delta, theta, alpha, beta, and gamma ranges), spectral entropy (a measure of signal complexity and cortical activation), and event-related responses during task-based paradigms (e.g., motor imagery and passive auditory language tasks). Higher spectral entropy and increased task-related cortical responses are generally interpreted as reflecting greater cortical activation and improved network engagement associated with arousal and awareness. Changes in resting-state spectral power and task-evoked responses will be assessed relative to baseline.
Time frame: Assessed at Baseline, 2 weeks after each treatment and 1 year follow-up.
Change in Resting-State Functional Connectivity (rs-fMRI)
Resting-state functional MRI will be used to assess changes in resting-state functional connectivity between the central thalamus and frontal/parietal cortical regions. Connectivity may be quantified using seed-based connectivity metrics and network-level connectivity measures derived from resting-state data. Changes will be assessed relative to baseline.
Time frame: Assessed at Baseline, 2 weeks after each treatment and 1 year follow-up.
Change in Task-Based Functional Connectivity
Task-based functional MRI will be used to assess brain activation and network engagement during structured paradigms, such as motor imagery and passive auditory language tasks. Task-related blood-oxygen-level-dependent (BOLD) responses will be used to assess regional brain activation and network-level engagement. Changes will be assessed relative to baseline.
Time frame: Assessed at Baseline, 2 weeks after each treatment and 1 year follow-up.
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