BlueCross and BlueShield of Montana Medical Policy/Codes
Sensory Stimulation for Coma Patients
Chapter: Medicine: Treatments
Current Effective Date: July 18, 2013
Original Effective Date: July 18, 2013
Publish Date: July 18, 2013

Sensory stimulation is intended to promote awakening and enhance the rehabilitative potential of coma patients.  Protocols may involve stimulation of any or all of the following senses:

  • Visual
  • Auditory
  • Olfactory
  • Gustatory
  • Cutaneous
  • Kinesthetic

Various stimuli may be used for each sense.  Protocols may differ by who performs the stimulation and where it is performed.  Professionals providing the stimulation may include:

  • Nurses
  • Occupational therapists
  • Physical therapists
  • Speech-language therapists

In some cases, family members may be trained in the techniques and are given primary responsibility for providing the therapy.  Treatment may be delivered in the hospital, at home or a nursing home.


Each benefit plan, summary plan description or contract defines which services are covered, which services are excluded, and which services are subject to dollar caps or other limitations, conditions or exclusions. Members and their providers have the responsibility for consulting the member's benefit plan, summary plan description or contract to determine if there are any exclusions or other benefit limitations applicable to this service or supply.  If there is a discrepancy between a Medical Policy and a member's benefit plan, summary plan description or contract, the benefit plan, summary plan description or contract will govern.


Sensory stimulation for coma patients is considered experimental, investigational and unproven.


This policy is based in part on a 1989 Blue Cross Blue Shield Technical Evaluation Center (TEC) Assessment that considered whether there was adequate scientific evidence to determine if sensory stimulation either led to quicker emergence from coma or improved rehabilitative potential.  The TEC Assessment concluded that to validate the effectiveness of coma stimulation, controlled clinical trials of comparable patients were required.  The literature available in 1989 did not meet these criteria; the five identified studies varied greatly in focus, design, methods, and degree of detail in the study's description.  Therefore, the TEC Assessment concluded that scientific data were inadequate to permit conclusions regarding the effectiveness of coma stimulation.

An updated search of the MEDLINE database for the period of 1998 through January 2006 failed to identify any controlled studies of coma stimulation.  The identified studies reported case series or descriptive studies of coma stimulation techniques.   In 1991, Wood and colleagues published a critique of coma stimulation that pointed out that the incomplete knowledge regarding information processing in the brain-injured state does not permit a scientific or theoretical basis for coma stimulation.  For example, Wood points out that the brain-injured patient is constantly exposed to sensory stimulation (e.g., skin care, range of motion exercises, bowel and bladder procedures, ambient noise in an intensive care unit), aside from any specific program of sensory stimulation.  In many cases, continual background stimulation may lead to habituation and thus, ultimately, undermine arousal.

A Cochrane systematic review (Lombardi, et al., 2002) was conducted to assess the effectiveness of sensory stimulation programs in patients in a coma or vegetative state.  The Cochrane review evaluated randomized control trials and non-randomized controlled clinical trials comparing any type of stimulation programs to standard rehabilitation in patients in a coma or vegetative state. Three reviewers independently identified relevant studies, extracted data and assessed study quality.  Three studies (one randomized controlled trial [Johnson, 1993] and two non-randomized controlled trials [Kater, 1989; Mitchell, 1990]) with 68 traumatic brain-injured patients in total, met the inclusion criteria.  The overall methodological quality was poor and the studies differed widely in terms of study design and conduct.  Also, due to the diversity in reporting of outcome measures, a quantitative meta-analysis was not possible.

None of the three studies in the Cochrane review provided useful and valid results on outcomes of clinical relevance for coma patients.  The study by Johnson did not report information on the main outcome measure, Glasgow Coma Scale, presenting instead data of questionable clinical relevance.  While the Kater study reported a significant difference in outcomes in favor of the actively treated group, these results must be interpreted with caution since the study included flawed statistical analysis in favor of the actively treated group.  The Mitchell study reported a significant difference in the mean length of coma in favor of the experimental group, but the clinical relevance of this measure apart from any other functional indicators is questionable.  The Cochrane researchers concluded that there is no reliable evidence to support or rule out the effectiveness of multisensory programs in patients in a coma or vegetative state.  The researchers further stated that the need to improve knowledge in this field and the lack of effective treatments indicates that treatment interventions based on sensory stimulation should be provided only in the context of well designed, adequately sized randomized controlled trials.

The American Academy of Neurology in a 1995 summary statement, “Practice Parameters: Assessment and Management of Patients in the Persistent Vegetative State”, makes no mention of sensory stimulation.

Effective treatment interventions for patients in coma or persistent vegetative state are lacking. Sensory stimulation has been proposed as a method to promote emergence from coma and return to a higher level of functioning. There is insufficient evidence in the published medical literature, however, to demonstrate that sensory stimulation improves the clinical outcome of patients in coma or persistent vegetative state.

2013 Update

A search of peer reviewed literature through June 2013 identified no new clinical trial publications or any additional information that would change the coverage position of this medical policy.


Disclaimer for coding information on Medical Policies

Procedure and diagnosis codes on Medical Policy documents are included only as a general reference tool for each policy. They may not be all-inclusive.

The presence or absence of procedure, service, supply, device or diagnosis codes in a Medical Policy document has no relevance for determination of benefit coverage for members or reimbursement for providers. Only the written coverage position in a medical policy should be used for such determinations.

Benefit coverage determinations based on written Medical Policy coverage positions must include review of the member’s benefit contract or Summary Plan Description (SPD) for defined coverage vs. non-coverage, benefit exclusions, and benefit limitations such as dollar or duration caps. 

ICD-9 Codes

Experimental, investigational and unproven for all diagnoses.

ICD-10 Codes

Experimental, investigational and unproven for all diagnoses.

Procedural Codes: 97139, 97799, S9056
  1. Sensory stimulation for coma patients.  Chicago, Illinois:  Blue Cross Blue Shield Association – Technology Evaluation Center Assessment Program (1989) 269-277.
  2. Mitchell, S., Bradley, V., et al.  Coma arousal procedure: a therapeutic intervention in the treatment of head injury.  Brain Injury (1990) 4(3):273-9.
  3. Wood, R. L.  Critical analysis of the concept of sensory stimulation for patients in vegetative states.  Brain Injury (1991) 5(4):401-9.
  4. Wood, R.L., Winkowski, T.B., et al.   Evaluating sensory regulation as a method to improve awareness in patients with altered states of consciousness: a pilot study.  Brain Injury (1992) 6(5):411-8.
  5. Hall, M.E. and S. MacDonald.  The effectiveness of directed multisensory stimulation versus non-directed stimulation in comatose CHI patients: pilot study of a single subject design.  Brain Injury (1992) 6(5):435-45.
  6. Davis, A.E. and J. J.White.  Innovative sensory input for the comatose brain-injured patient. Critical Care Nursing Clinics of North America (1995) 7(2):351-61.
  7. American Academy of Neurology.  Practice Parameters.  Assessment and management of patients in the persistent vegetative state (Summary Statement).  Report of the quality standards subcommittee of the American Academy of Neurology.  (1995/1998) Accessed October 2006.
  8. Lombardi, F., Taricco, M., et al.  Sensory stimulation for brain injured individuals in coma or vegetative state. Cochrane Database Systems Review (2002) 2:CD001427. (Also available in Clinical Rehabilitation (2002) 16(5):464-72.
  9. Goetz, C.  Textbook of Clinical Neurology – 2nd ed.  Chicago, Illinois:  W.B. Saunders Company, (2003).
  10. Davis, A.E., and A. Gimenez.  Cognitive-behavioral recovery in comatose patients following auditory sensory stimulation.  Journal of Neuroscientific Nursing (2003 August) 35(4): 202-9, 214.
  11. Gelling, L., Shiel, A., et al.  Commentary on Oh H. and Seo, W. (2003) Sensory stimulation programs to improve recovery in comatose patients.   Journal of Clinical Nursing (2004 January) 13(1): 125-7.
  12. Brust, J.C.M.  Symptoms of neurologic disorders.  Merritt’s Neurology – Section 1.  New York, New York:  Lippincott Williams and Wilkins (2005).
May 2013  New 2013 BCBSMT medical policy.  Sensory stimulation for coma patients is considered experimental, investigational and unproven. 
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Sensory Stimulation for Coma Patients