Rehabilitation of attention following traumatic brain injury

Traumatic brain injury results in injury to frontal, temporal, meso-limbic, midbrain reticular formation areas, which are involved in the mediation of aspects of attention. Cognitive and behavioral changes following TBI have a significant impact on capacity for work, study, leisure, social activities and relationships. Traumatic brain injury (TBI) is the leading cause of death and disability in those aged under 40, occurring most frequently in males aged 15-24 years and resulting most commonly from motor vehicle accidents (Kraus & McArthur, 1999; Fortune & Wen, 1999). These predominantly young people are generally in the process of completing their studies or learning vocational skills and establishing important personal and social relationships. Blunt trauma to the head results in a combination of acceleration-deceleration and rotational forces which may result in cerebral contusion, and diffuse axonal injury, particularly in the frontal and temporal lobes. Shearing strains are created between tissues of different density, causing lesions in areas such as the midbrain reticular formation, cerebellar peduncles, basal ganglia, hypothalamus, fornices and corpus callosum (Gentleman, 1999; Graham, 1999; Povlishock & Katz, 2005). Secondary effects of brain injury, including edema, raised intra-cranial pressure, cerebral hemorrhage, hypotension or respiratory failure, may result in further damage due to pressure effects or hypoxia. The hippocampus and thalamus are particularly vulnerable to the effects of hypoxia. As a result of all these mechanisms, TBI tends to result in diffuse, bilateral injury, affecting many brain regions including the frontal, temporal, meso-limbic, midbrain reticular formation areas. All of these areas are involved in the mediation of aspects of attention. As a consequence of this damage, TBI results in a range of cognitive impairments, particularly in the domains of attention, memory and executive function, as well as behavioral and emotional changes including inflexibility, impulsivity, reduced behavioral control or inhibition, reduced initiative, mood swings and other affective changes. The injured person frequently has a lack of self-awareness of these changes, which tend to be more persistent than physical disabilities (Olver et al., 1996).