Injuries to the head may cause damage to the skull itself, the brain and facial bones. Head injuries can be described as either blunt injuries or penetrating injuries. Blunt injuries are associated with acceleration or deceleration mechanisms. With these injuries the brain may be injured as it moves back and forth in the cranial vault. Penetrating injuries from weapons or exploding objects may injure soft tissues, vascular and nerve structures as well as the skull and brain.
Skull Fractures
It requires a significant amount of force to fracture the rigid skull. With an injury to the skull, concurrent injuries to the brain and spine should be considered. There are three primary types of skull fractures: linear, depressed and basilar. According to Ohio State University Medical Center, linear skull fractures are the most common type. With the linear fracture, the skull has a break in the bone, but the bone does not move. These fractures require very little intervention, and the patient is often observed in the hospital for any changes in her condition .
A depressed skull fracture extends below the level of the surface of the skull and can cause brain tissue compression. These fractures are often associated with more serious injury and require additional monitoring based on the symptoms they cause.
Basilar skull fractures are injuries that occur at the base of the skull and are the most serious of the skull fractures, according to Ohio State University Medical Center. Persons with basilar skull fractures may have clear drainage from the nose and ears, which indicates the presence of a tear in the covering of the brain. Basilar skull fractures may also cause bruising under the eyes and behind the ears.
There is a fourth type of skull fracture called a diastatic skull fracture that more often occurs in newborns and infants. At birth the skull consists of bone plates that are not fully joined together. As the child grows, the bone plates fuse together. The joint where the bones fuse is called the suture. A fracture that causes the skull to separate at the suture is called a diastatic fracture.
Concussion and Contusion
"Sheehy's Manual of Emergency Care" describes a concussion as an injury that results from movement of the brain within the bony skull. The movement will cause injury to the brain, usually in a specific area of the brainstem that controls the arousal or wakefulness of the individual. Persons who sustain a concussion may or may not have a brief loss of consciousness with the injury. A concussion typically is a brief, limited process that usually requires no specific intervention.
A contusion is the bruising of the surface of the brain. The outcome of the contusion will vary depending upon its size and location. Symptoms may include a prolonged loss of consciousness, confusion, speech problems, and weakness with visual disturbances.
Bleeding Injuries
The brain is covered by three protective layers of tissue. The layers from outside to inside are called the dura, the arachnoid, and the pia mater. Injures that cause bleeding within the skull or the brain are named based on their location with respect to the layers covering the brain. An epidural injury occurs between the skull and the outermost layer, called the dura. This type of bleeding injury usually involves an artery. Because an artery will bleed rapidly, blood from an epidural injury will accumulate rapidly. This type of head injury requires immediate surgical intervention. A subdural hematoma is a brain injury that occurs in an area called the subdural space. The subdural space is located just below the inner layer of the dura. The bleeding from a subdural occurs when the small veins between the surface of the brain and its outer covering (the dura) stretch and tear, allowing blood to collect. With this injury, the signs and symptoms may occur rapidly, or they may be seen days to weeks after the initial injury.
Diffuse Axonal Injures
Diffuse axonal injuries are described by Ohio State Medical as injuries caused by shaking of the brain back and forth, which can happen in car accidents, from falls or from shaken baby syndrome. Diffuse axonal injuries are different from a concussion because the damage occurs over a more widespread area. Because of the widespread damage, diffuse axonal injuries may be more devastating than other head injuries. With this injury, prolonged coma may occur due to injury of the brainstem, which is the wakefulness center of the brain.
Head and Facial Injuries
Head injuries may have associated facial and soft tissue injuries. Common facial injuries seen with head trauma may include injuries to the lower jaw and middle facial bones. Fractures to these structures may have an impact upon the person's bite and vision.
References
- "Emergency Nursing Core Curriculum"; Saunders Elsevier; 2007
- "Current Diagnosis & Treatment Emergency Medicine"; McGraw Hill. Lang; 2008
- Sheehy's Manual of Emergency Care"; Elsevier Mosby: 2005
- Ohio State University Medical Center: Head Injury
