Unawareness of neurologic deficits or illness is also referred to as anosognosia, and is commonly found in patients following various types of brain injury. Unfortunately, while impaired awareness is a pervasive finding among brain injured individuals, it remains very difficult to measure -in a quantitative manner. Prigatano points out three important tenets that are necessary to consider when examining impaired awareness: 1) brain injuries are constantly changing over time; 2) different types of impaired awareness emerge with different types of brain injuries; and 3) disorders of self-awareness are comprised of both cognitive and emotional components.

Prigatano has separated these disorders of self-awareness into two areas: 1) complete and 2) partial. In a complete syndrome, you see what is typically thought of as a classic anosognosia, where there is no experience, and hence no awareness of any impairment. Generally speaking, complete unawareness occurs either with bilateral brain damage or in the early stages of brain injury. This is important is because some individuals are able to progress from total anosognosia to partial awareness of their deficits in the later stages of recovery.

Four different types of self-awareness have been identified by Prigatano: 1) frontal heteromodal syndrome (lack of insight into planning, social judgment, and impulse control deficits); 2) parietal heteromodal syndrome (decreased awareness of hemiparesis and inattention to one side of his/her environment); 3) temporal heteromodal syndrome (impaired awareness of memory and language deficits; and 4) occipital heteromodal syndrome (poor awareness of cortical blindness or ability to recognize objects).

With regard to emotional factors, individuals with complete anosognosia usually do not experience emotional distress due to their lack of awareness of their deficits. However, as self-awareness increases, different coping mechanisms emerge that are accompanied by variable levels of distress. These include: 1) non-defensive, where a person may acknowledge some type of deficit yet underestimate its overall impact upon social, emotional, and occupational functioning; and 2) defensive, where the acknowledgment of a deficit produces intolerable anxiety for the individual. In this case, he/she employs various defense mechanisms, such as denial, to be able to manage the anxiety and go on with the business of living.

Overall, Prigatano points out that it is important to recognize the different brain regions that are responsible for specific self-awareness deficits. However, examining the interplay between psychological defense mechanisms and cognitive impairments becomes vital when attempting to understand and address the various types of deficits in selfawareness. Following this paradigm, comprehensive treatment, from acute to postacute stages, must take into consideration a of these components of self-awareness.

For more information on this topic, please refer to:
Prigatano, G. P. (Winter/Spring 2000). "Syndromes of impaired awareness after brain injury".- Division of Clinical Neuropsychology Newsletter 40, 1-8, pp. 5 & 14-15.
Prigatano, G. (1999). Principles of Neuropsychological Rehabilitation, Oxford University Press, New York.

Jennifer McCain, Psy.D Neuropsychologist Jamaica Hospital TBI Unit