Coma
The Coma Process
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A person with brain injury more often than not experiences some level of coma immediately or shortly after the onset of the injury. Unlike what has been inaccurately depicted in television and movies, coma, from a physiological standpoint, is significantly different than a state of sleep. Three aspects of reduced consciousness need to be defined to better understand these phenomena: Coma, persistent vegetative state, and locked-in syndrome.
In coma, a person is in a state of reduced consciousness or is unconscious. (The neurosurgical definition of coma is: no eye opening, no recognizable speech, no following motor commands.) In this state, the person exhibits differing levels of responsiveness to touch, pain, and verbal commands. It is therefore proper to talk about depth or levels of coma rather than thinking of coma as an all or none type of experience.
The person who is in a wakeful state but with profound nonresponsiveness is referred to as a persistent vegetative state. In this state the cerebral cortex of the brain is not functioning, and the person is unable to respond to things in the environment. Many individuals can remain in this state for long periods of time.
In the condition of locked-in syndrome, the patient appears unresponsive without the ability to move or verbally communicate, yet has full cognitive abilities. Such individuals are able to use an eye blinking response to communicate.
A common tool used to measure coma is the Glasgow Coma Scale. It evaluates a person's ability to open eyes, best verbal response, and best movement response.
Glasgow Coma Scale Ranges
13 - 15 Mild Severity
9 - 12 Moderate Severity
3 - 8 Severe Severity
The Ranchos Los Amigos Level of Cognitive Functioning scale is another measure used to describe the awareness and responsiveness of a person with brain injury. As recovery occurs, the person will demonstrate abilities at higher and higher levels on this scale. The scale starts at a Level I - No Response; this is when the patient is unresponsive to all stimuli. Level VIII - X Purposeful-Appropriate is characterized by correct responses and the ability to carry over new learning.
There are some specific rehabilitation goals for persons in a reduced state of consciousness, especially coma. It is important for the patient's limbs to be moved and ranged. Since the patient is not mobile there are risks for the patient to lose their range of motion in the extremities. Involuntary muscle tightness called spasticity, is also common in brain injury and can affect the use of muscles if not addressed. A physical therapist may be involved to treat these problems. Another risk for the patient in coma is to develop pressure sores or skin ulcers. Nursing staff and family members can help prevent these ulcers by turning the patient’s position in the bed every hour or two or as directed by therapy staff.
We do not know how much a patient is able to comprehend or if there is any degree of awareness when that person is in a deep level of coma. As the patient emerges from coma, more awareness of those around him increases. For these reasons it is important to be careful in the communications that occur around and about the patient during coma.
Jay Uomoto, Ph.D. is a Professor in the Department of Graduate Psychology at Seattle Pacific University and teaches neuroscience, personality and rehabilitation psychology courses in the Ph.D. Clinical Psychology Program. His research emphasizes the neuropsychology and multicultural aspects of traumatic brain injury, long-term care patterns in older Japanese Americans, as well as studies in interpersonal changes after brain injury. Dr. Uomoto is certified in Health Care Ethics. He also has a private practice in neuropsychology and rehabilitation psychology.