Do Sensory Stimulation Programs Have an Impact on Consciousness Recovery?

Abstract

Objectives: Considering sensory stimulation programs (SSP) as a treatment for disorders of consciousness is still debated today. Previous studies investigating its efficacy were affected by various biases among which small sample size and spontaneous recovery. In this study, treatment-related changes were assessed using time-series design in patients with disorders of consciousness (i.e., vegetative state—VS and minimally conscious state—MCS).Methods: A withdrawal design (ABAB) was used. During B phases, patients underwent a SSP (3 days a week, including auditory, visual, tactile, olfactory, and gustatory stimulation). The program was not applied during A phases. To assess behavioral changes, the Coma Recovery Scale-Revised (CRS-R) was administered by an independent rater on a weekly basis, across all phases. Each phase lasted 4 weeks. In a subset of patients, resting state functional magnetic resonance imaging (fMRI) data were collected at the end of each phase.Results: Twenty nine patients (48 ± 19 years old; 15 traumatic; 21 > a year post-injury; 11 VS and 18 MCS) were included in our study. Higher CRS-R total scores (medium effect size) as well as higher arousal and oromotor subscores were observed in the B phases (treatment) as compared to A phases (no treatment), in the MCS group but not in the VS group. In the three patients who underwent fMRI analyses, a modulation of metabolic activity related to treatment was observed in middle frontal gyrus, superior temporal gyrus as well as ventro-anterior thalamic nucleus.Conclusion: Our results suggest that SSP may not be sufficient to restore consciousness. SSP might nevertheless lead to improved behavioral responsiveness in MCS patients. Our results show higher CRS-R total scores when treatment is applied, and more exactly, increased arousal and oromotor functions.

Neurorehabilitation of Traumatic Brain Injury (TBI): A Clinical Review

“…Similar findings were reported by two groups using multimodal stimulation programmes [47,48]. The latter study showed that effects on the CRS-R, notably increased arousal and oromotor functions, were only found in MCS patients and not in VS patients [48].…”

“…In a preliminary report of a randomised placebo-controlled trial assessing the effect of familiar auditory sensory training, Pape and colleagues noted significant gains in the Coma-near-coma scale, representing arousal and awareness in patients with DOC [46]. Similar findings were reported by two groups using multimodal stimulation programmes [47,48]. The latter study showed that effects on the CRS-R, notably increased arousal and oromotor functions, were only found in MCS patients and not in VS patients [48].…”

“…Furthermore, it seems reasonable to provide care in a specialized institution given the particularities in this population. Besides the aforementioned pharmacological options and multi-sensory stimulation programmes [46,47,48], prevention and treatment of typical complications are often the main focus in these situations. It comprises means to maintain nutritional status and muscle mass, to prevent and treat spasticity and contractures, and to avoid circulatory deconditioning.…”

Therapeutic interventions in patients with prolonged disorders of consciousness

“…[68][69][70][71] A recent uncontrolled ABAB protocol tested the effects of a multi-sensory stimulation program including auditory, visual, tactile, olfactory, and gustatory stimuli (20 minutes per session applied 3 days per week for 4 weeks). 72 Higher CRS-R total scores were observed during the treatments periods (B) compared to baselines (A) in MCS but not in UWS patients groups. Double-blind RCTs need to further evaluate the possible superiority of a multi-sensory approach as compared to only one type of stimulation.…”

Electrophysiological and Neuroimaging Studies – During Resting State and Sensory Stimulation in Disorders of Consciousness: A Review

“…Further, it can be easily used as a bedside-assessment tool for DOC patients. However, several studies (Boly et al, 2007;Di et al, 2007;Sharon et al, 2013;Liang et al, 2014;Bodien et al, 2017;Cheng et al, 2018) have also used fMRI, which provides both high-resolution structural imaging as well as functional imaging, thus giving crucial information for diagnosis that could possibly never be ascertained by EEG (Giacino et al, 2014). The biggest issue with fMRI is that it is extremely sensitive to movement artifacts and therefore is difficult to record for these patients.…”