Date Presented 04/01/2022

Disorders of consciousness (DOC) have a severe impact on an individual’s awareness and arousal. Sensory stimulation is an intervention approach to promote arousal and behavioral responsiveness by the application of environmental stimuli in patients with DOC. Eighteen articles were included in this review and showed that patients had a greater increase in arousal when auditory stimulation was applied unimodally, multimodally, or by family members and was personally salient to the patient.

Primary Author and Speaker: Haley Robinson

Contributing Authors: Jewel E. Crasta

PURPOSE: Disorders of consciousness (DOC) severely impacts an individual’s awareness and arousal. The main goal when working with these patients is to increase arousal while preventing secondary medical complications. Sensory stimulation is an intervention approach aimed at promoting arousal and behavioral responsiveness by the application of environmental stimuli in DOC patients. The purpose of this systematic review was to assess the effectiveness of sensory stimulation to increase arousal in patients diagnosed with DOC.

DESIGN: The Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines was used to conduct the systematic review.

METHOD: Three databases were searched including PubMed, CINAHL, and OTSeeker using keywords related to disorders of consciousness, sensory stimulation, and arousal . Inclusion criteria consisted of intervention studies where participants received sensory stimulation, participants were 18+, and diagnosed with DOC. Studies were excluded if they were written before the year 2000 and if the stimulation protocol was not defined. The initial search resulted in 373 articles and after removing duplicates and screening titles and abstracts 42 articles were included for full text review. A total of 18 articles were included in the final systematic review analysis.

RESULTS: The quality of evidence and strength of recommendation were evaluated using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) process. Out of the 18 articles included for review, eight were randomized controlled trials (level II), three were quasi-experimental trials (level III), and seven longitudinal types of studies (level IV). Each article examined arousal level after receiving a sensory stimulation intervention. For this review sensory stimulation was broken into three categories: auditory stimulation, family-based stimulation, and multimodal stimulation. Both auditory and multimodal stimulation had moderate level of evidence supporting its use. Family-based stimulation had a high level of evidence supporting its use to increase arousal in DOC patients.

CONCLUSION: Sensory stimulation intervention increased arousal in DOC patients across all three categories. Individuals had a greater increase in arousal when auditory stimulation was applied either unimodal, multimodal, or by family members. The greatest increase in arousal was seen if the auditory stimulation was personally salient to the patient. Individualized intervention protocols should be created based on patient preference for each stimulus. The intervention should be applied multiple times a day that includes some type of auditory stimulation. An emphasis should be placed on involving caregivers/family in the intervention. Even though this systematic review found moderate to high evidence to support the use of sensory stimulation to increase arousal further research is warranted for sensory stimulation programs with larger sample sizes, using recommended standardized assessments, and similar protocols.

IMPACT STATEMENT: Occupational Therapists (OTs) are trained in sensory regulation techniques in which sensory stimulation is based on. This makes OTs well equipped to provide the controlled exposure to sensory stimuli that is involved in sensory stimulation. OTs should create individualized intervention protocols for each patient that are tailored to their preferences for each stimulus. The use of a sensory stimulation intervention can help therapists increase arousal in their DOC patients during therapy sessions and, in turn, increase their ability to lead therapeutic and productive sessions.


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Salmani, F., Mohammadi, E., Rezvani, M., & Kazemnezhad, A. (2017). The effects of family-centered affective stimulation on brain-injured comatose patients’ level of consciousness: A randomized controlled trial. International Journal of Nursing Studies, 74, 44–52.

Cheng, L., Cortese, D., Monti, M. M., Wang, F., Riganello, F., Arcuri, F., Di, H., & Schnakers, C. (2018). Do Sensory Stimulation Programs Have an Impact on Consciousness Recovery? Frontiers in Neurology, 9.

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