If your loved one has a severe brain injury, it may be hard to tell whether they are conscious, even if they appear awake. It may not be clear how aware they are of themselves or their environment. A DoC diagnosis describes a person’s level of consciousness. Having a correct DoC diagnosis is very important. Your loved one’s DoC diagnosis may affect their future recovery, decisions about treatment, and access to rehabilitation. If you understand your loved one’s condition, you can make informed decisions about their care needs. You can also know what to expect for recovery. 
There are behavior-rating scales specially designed for assessing persons with DoC. These scales may help correctly determine your loved one’s DoC diagnosis. They can be performed at the bedside to help determine how well the brain is functioning. Scoring is based on behavior responses to commands (e.g., “Look at the cup.”) and stimuli (e.g., response to pain, sound, light). Behavior rating scales should be given often, over a period of time (e.g., days or weeks) to help correctly determine your loved one’s level of consciousness. These scales may also be used to monitor your loved one’s progress over time.

Your loved one’s care team may use one or more assessment tools which they believe would be most helpful in the DoC treatment and planning. Although aimed at clinicians, the general descriptions provided below can help you understand how each scale is used and the behaviors they measure.

The Coma Recovery Scale (CRS-R) - This behavior rating scale has the most research evidence to support its use. It is the most highly recommended scale. The CRS-R is considered the informal “gold standard” behavior rating scale for persons with DoC.

Additional assessment tools that may be used as well but do not have as much evidence to support their use include:

  • The Sensory Modality Assessment and Rehabilitation Technique (SMART) - identifies potential awareness in adults with severe brain damage in an unresponsive wakefulness syndrome / vegetative state and identifies the functional and communication abilities of patients in a minimally-conscious state. 
  • Western Neuro Sensory Stimulation Profile (WNSSP) - examines the degree of responsiveness of a patient with disorders of consciousness and charts basic cognitive sensory recovery over time.
  • The Sensory Stimulation Assessment Measure (SSAM) - was developed as a tool for measuring the senses of an unconscious patient over a long period of time. It is intended to assist in treatment planning and to address the demands of scientific research.
  • Wessex Head Injury Matrix (WHIM) - was developed to assess subjects in and emerging from coma as well as those in unresponsive wakefulness syndrome / vegetative and minimally conscious states. It is a 62-item observational matrix that collects data by observation as well as the person’s reaction to specific stimuli.
  • The Disorders of Consciousness Scale (DoCS-25) - is a structured clinical assessment tool that was developed to detect subtle changes in observable indicators of neurobehavioral functioning during recovery of consciousness following a severe traumatic brain injury. It can be used to monitor recovery of consciousness and evaluate the effects of interventions in order to better inform clinical decision-making and prognosis of recovery.

How can level of consciousness be determined when behavior responses are unclear?

In some cases, it may be hard to determine your loved one’s level of consciousness, even when behavior rating scales are used often. To establish a correct DoC diagnosis, results from behavior rating scales should be used along with information from other sources (e.g., brain imaging, other tests, and informal observations of your loved one’s behavior). If your loved one’s behaviors are unclear, Individual Quantitative Behavioral Assessment (IQBA) may also be used along with behavior rating scales to help determine level of consciousness. IQBA is an advanced type of behavior assessment that may help answer questions specific to your loved one. For example, IQBA may be used to help answer the question of whether a person is moving their finger on purpose, or whether they are trying to communicate when they slowly blink their eyes.

There are also other, less available methods that may help determine level of consciousness when behavior responses are unclear. Examples include advanced brain imaging and advanced studies of the brain’s electrical activity. These studies can help look for signs of awareness that your loved one is unable to show on behavior exams. At this time, these technologies are mostly used in research settings.

What are some other reasons it may be difficult to correctly determine my loved one’s level of consciousness?

Brain injuries can cause many kinds of medical and neurological conditions which can make assessment and treatment more challenging. Examples of common problems include breathing problems, seizures, skin breakdowns or bedsores, and infections. For a more detailed review of medical complications that may impact on your loved one’s recovery, click here: Complications

The section below includes examples of other conditions that may prevent clinicians from seeing key behaviors that suggest a greater level of awareness or functional abilities. Click in the boxes below for more detailed information on each disorder.


How Condition Impacts DoC

Abulia is a disorder that affects someone’s ability to be able to start or finish something.

Someone with abulia may have awareness of what is going on around them but are not able to respond to a question/command or prompts.

Aphasia is a language disorder in which an individual can have difficulty understanding what is spoken to them or with expressing themselves through speaking or writing.

Many of the assessments used for DoC rely on a person’s language abilities, by asking them to follow commands, answer simple yes/no questions, or recognize objects.

Apraxia (or Dyspraxia)
Apraxia is a motor disorder in which an individual can have difficulty performing well-learned motor tasks, like speaking, moving their face, moving their eyes, or using objects (like a cup or comb).

Apraxia may interfere with someone’s ability to track objects with their eyes, follow commands (open your eyes, stick out your tongue), answer simple yes/no questions, or use common objects when asked (e.g., show me how you use a cup).

Blindness or Deafness
Your loved one may have had problems with vision or hearing since before their injury. New problems may occur if your loved one’s brain injury involved damage to one or both eyes or ears. Problems with vision or hearing may also occur if their injury affected the parts of the brain that process vision or sound, even when the eyes and ears are not damaged.

Someone with this injury may behave like they cannot see (e.g., do not direct their gaze to objects) or hear (e.g., do not respond to commands or loud noises), even though they are conscious and aware.
Cranial Nerve Damage
The cranial nerves are cable-like bundles that help the brain communicate with the body. There are 12 pairs of cranial nerves. Some of these nerves send information from the sense organs to the brain. Others are involved in controlling movement of the eyes, face, tongue, jaw, neck, and shoulders. You can scroll to the middle of the webpage below for more information on the cranial nerves.


Assessment of persons with DoC often involves asking the person to follow commands, and/or seeing how they respond to sensory information (e.g., things they see, hear, or feel). Cranial nerve damage may cause a loss of sensations like taste, smell, sight, touch, or sound. There may also be problems moving the eyes, face, jaw, or tongue. If your loved one has cranial nerve damage, this may affect their ability to respond to assessment tasks, even when they are conscious and aware of their surroundings.

How will my loved one’s progress in rehabilitation be measured?

Based on practice guidelines, it is recommended that behavior rating scales such as the Coma Recovery Scale (CRS-R) be used to monitor recovery and response to treatment efforts over time. Rating scales should be repeated on a regular basis to help track changes in your loved one’s level of wakefulness, pain, ability to follow commands, and communicate.

In addition to behavior rating scales, programs may also use other strategies or tools to monitor your loved one’s progress in rehabilitation. Progress should be monitored across multiple areas of function. This may include measures of your loved one’s ability to participate with rehabilitation tasks. It may also include ratings of the level of assistance your loved one needs to perform different body functions, move their body, communicate, and perform self-care tasks (e.g., feeding, eating, getting dressed, brushing hair, etc.).