Introduction to Disorders of Consciousness

Consciousness is the state of being awake and aware of one’s surroundings.  A disorder of consciousness (DOC) is a diagnosis given when someone has difficulty maintaining wakefulness and/or has impaired awareness of him/herself and his/her environment due to a medical condition. 

What causes a Disorder of Consciousness?

Disorders of consciousness are caused by severe injuries to the brain.  Diffuse axonal injuries, certain types of strokes, oxygen deprivation injuries, and injuries involving the brainstem commonly affect levels of consciousness. 

For more information about what happens to the brain during and after an injury, please refer to Types of Brain Injury content on this website.

What are the states of Disordered Consciousness?

There are three states of disordered consciousness:

 An individual may demonstrate different degrees of alertness, self-awareness, and interaction within their environment at each of these levels, progressing towards emergence from a minimally conscious state. Please see below for more detailed information about each of these. 

When an individual sustains a traumatic brain injury (e.g. from a car accident), medical staff may use a scale called the Rancho Los Amigos Cognitive Recovery Scale to identify different stages of recovery.  Click HERE for more information about the Rancho Scale.  Video examples of each state can also be viewed HERE.

Emergence from a Minimally Conscious State 

When an individual is conscious, they demonstrate purposeful interaction with their environment. The two behaviors used to determine whether an individual has emerged into a fully conscious state are:

  • Consistent and accurate communication of yes/no responses
  • Purposeful use of objects 

Additional Resource on Disorders of Consciousness

To learn more about coma, vegetative state and minimally conscious states click HERE to read “Facts about Vegetative and Minially Conscious States after Severe Brain Injury.”