NCT06922123

Tactile Stimulation in Disorders of Consciousness (DoC)

Behavioural and Neurophysiological Reactions During Tactile Stimulation in Patients Suffering From Disorders of Consciousness (DoC)

• Status: Not Yet Recruiting
• Phase: —
• Study type: Observational
• Enrollment: 30 (estimated)
• Sponsor: Anna Estraneo · Academic / Other
• Sex: All
• Age: 18 Years
• Healthy volunteers: Not accepted

Summary

The aim of this project is to evaluate the behavioural and neurophysiological responses to pleasant touch in patients with disorders of consciousness (DoC) and to determine whether these responses are related to the level of consciousness. Specifically, the study aims to: 1. explore the relationship between pleasant tactile stimulation and behavioural and neurophysiological responses in patients with DoC; 2. determine whether behavioural responses to pleasant touch stimulation correlate with the level of consciousness; 3. assess whether behavioural responses vary depending on the valence of the stimulus (pleasant, neutral, or unpleasant); 4. examine neurophysiological responses to tactile stimulation using functional near-infrared spectroscopy (fNIRS), and evaluate whether brain activation patterns are associated with behavioural responses; 5. improve diagnostic accuracy in patients with DoC by exploring the value of somatosensory responses in distinguishing unresponsive wakefulness syndrome (UWS) from minimally conscious state (MCS) or conscious patients; 6. explore the potential usefulness of implementing this type of stimulation within rehabilitation programs to support better recovery of consciousness.

Detailed description

Patients will be enrolled at the participating centers and included in the study only after at least two evaluations using the Coma Recovery Scale-Revised (CRS-R), in order to ensure a stable diagnosis of the level of consciousness. At the beginning of the protocol, non-invasive fNIRS optodes will be placed on the patient's forehead using a frontal headband, and 15 minutes of resting-state brain activity will be recorded. The Simplified Evaluation of CONsciousness Disorders (SECONDs) will then be administered to assess the patient's level of consciousness, followed by the tactile stimulation protocol. The tactile stimulation protocol involves 8 areas of the body (anterior and posterior forearm, palm and back of the hand, on both right and left sides) and 6 stimuli grouped into three categories: pleasant objects (makeup brush, plush fabric), neutral objects (sponge, rubber fabric), and unpleasant objects (dishnet, hairbrush). Each stimulus is mounted on a 10 cm wooden stick attached to a cork base. Each stimulation lasts 15 seconds and is manually administered using light circular movements over an area of approximately 5 cm² at a speed of 5 cm/s, following a randomized sequence. A 10-second rest period will be provided between stimulations. Patients will receive three distinct blocks of stimulation: unpleasant stimuli (first block), pleasant stimuli (second block), and neutral stimuli (third block), with the block order randomized across participants. After each block, the SECONDs will be re-administered to detect any changes in the level of consciousness. An additional 15-minute resting-state fNIRS recording will follow the stimulation phase. All sessions will be video-recorded to allow two independent experimenters to evaluate behavioural responses (e.g., facial expressions, vocalizations, body movements, and emotional reactions such as crying, smiling, or grimacing) and compare the effects of different stimulations. At the end of the session, fNIRS optodes will be removed. The entire experimental procedure will last approximately 90 minutes.

Conditions

• Disorders of Consciousness

Interventions

Type	Name	Description
BEHAVIORAL	Tactile stimulation	Patients will undergo a resting-state EEG and fNIRS recording, followed by the administration of the SECONDs scale. Tactile stimulation will then be performed on eight areas of the body (internal and external forearms, palms and backs of the hands on both sides) using six different stimuli categorized as pleasant, neutral, or unpleasant. Stimuli will be applied manually in randomized blocks. EEG and fNIRS data will be recorded before, during, and after stimulation. Behavioural responses will be evaluated through video analysis by independent raters. The session will last approximately 90 minutes.
DEVICE	Neurophysiological Monitoring with SedLine	SedLine is a non-invasive neurophysiological monitoring device used to record the brain's electrical activity (EEG) through frontal electrodes. In this study, SedLine is employed to measure resting-state and stimulus-evoked cortical responses in patients with disorders of consciousness (DoC), in combination with functional near-infrared spectroscopy (fNIRS). The EEG signals are used to assess changes in neural activity before, during, and after tactile stimulation with various affective valences (pleasant, neutral, unpleasant). This combined multimodal approach enhances the understanding of sensory processing and cortical reactivity in patients with impaired consciousness.

Timeline

• Start date: 2025-04-01
• Primary completion: 2025-07-01
• Completion: 2025-10-01
• First posted: 2025-04-10
• Last updated: 2025-04-23

Regulatory

• FDA-regulated device study