148 Chapter 8
for patients with severe traumatic brain injury is attributed to reducing this pressure and increas-
ing blood f low to the brain. According to the International Brain Injury Association (2015), an
estimated 5.3 million Americans are living with disability associated with traumatic brain injury.
Head-Injured Persons
Several studies have focused on the types of persons who suffer traumatic brain injuries. All
studies show that men, particularly young ones, are at least twice as likely as women to be involved.
Hickey (1997) reports that about 50% of all head injuries are caused by motor vehicle accidents,
followed by falls (21%) and assaults and vio lence (12%). “In the very young and in the el derly, the
primary cause of injury is falls, whereas ABI [accidental brain injury] in young adults is more
likely to be caused by accidents and assaults” (Petit, 2001, p. 70). According to the International
Brain Injury Association (2015), the highest rate of injury occurs between the ages of 15 and 24,
and persons under the age of 5 and over the age of 75 are also at higher risk. Drug and alcohol
use, as well as risky jobs and recreational activities, are also positively correlated with traumatic
brain injuries. Interestingly, persons who are admitted to a hospital for a traumatic brain injury
are likely to have been previously hospitalized for a similar injury. The following is a profile of the
typical head- injured person:
A young single male with poor education and academic skills, working in a job where the
risk of accidental injury is great, earning below average income, who engages in risk- taking
be hav iors while using alcohol or recreational drugs, and who has previously been admitted
to a hospital for a traumatic head and neck injury. (Tanner, 2003b, p. 118)There are two types of head injuries: open and closed. An open head injury occurs when an
object— a projectile or missile— penetrates the skull and brain. According to the National Institute
of Neurological Disorders and Stroke (2015), approximately half of severely head- injured persons
will need surgery to remove or repair hematomas (ruptured blood vessels) or contusions (bruised
brain tissue). A common projectile in an open head injury is a bullet fired from a gun. Others
include shrapnel from a bomb explosion and bolts or tools falling from high places in industrial
accidents. Projectiles and missiles damage the brain when they impact and enter it.
A closed head injury occurs when an object impacts but does not penetrate the skull and brain.
These injuries are often caused by blunt blows. The force of the blow causes the brain to acceler-
ate and decelerate. Often rotational acceleration of the brain results in shearing of axons (Gillis &
Pierce, 1996), the parts of the brain that carry nerve impulses away from cell bodies. The brain is
suddenly accelerated by the force of the blow and it rotates, tearing and shearing the axons within.
Open and closed head injuries can cause focalized and diffuse brain injury. Focalized injury
affects one identifiable area of the brain. Diffuse injury involves more than one site. In some types
of head injury, brain damage is primarily limited to one area. Many high- impact head injuries
produce coup and contrecoup effects. The coup effect occurs at the site of the initial impact. The
contrecoup effect is on the opposite side of the brain because of one of the laws of physics: for
every action, there is an equal and opposite reaction. This damage occurs because of the recoil of
the brain inside the skull. “If the head is not immobilized when struck, the majority of the injury
may be to the brain on the opposite side of the head from impact— a ‘contrecoup’ injury” (Fuller
& Goodman, 2001, p. 281).
Neurogenic Communication Disorders and
Traumatic Brain Injury
To a limited extent, the site or sites of the brain damage determine the patient’s communication
disorder. If the primary speech and language centers of the brain are damaged, there may be one
or more neurogenic communication disorders. When the damage is limited to these areas, patients