Almost 10 million head injuries occur annually in the United States, about 20% of which are serious enough to cause brain damage.
Head trauma can cause immediate loss of consciousness. Prolonged alterations in consciousness may be due to parenchymal, subdural, or epidural hematoma or to diffuse shearing of axons in the white matter. The term “concussion” is now applied to all cognitive and perceptual changes experienced after a blow to the head, whether or not consciousness is lost. Skull fracture should be suspected in pts with CSF rhinorrhea, hemotympanum, and periorbital or mastoid ecchymoses. Glasgow Coma Scale (Table 19-2) is useful for grading severity of brain injury.
APPROACH TO THE PATIENT: Head Injury
Medical personnel caring for head injury pts should be aware that:
Spinal injury often accompanies head injury and care must be taken to prevent compression of the spinal cord due to instability of the spinal column.
Intoxication is a frequent accompaniment of traumatic brain injury; when appropriate, testing should be carried out for drugs and alcohol.
Accompanying systemic injuries, including ruptures of abdominal organs, may produce vascular collapse or respiratory compromise requiring immediate attention.
Minor Head Injury The pt with minor head injury who is alert and attentive after a short period of unconsciousness (<1 min) may have headache, dizziness, faintness, nausea, a single episode of emesis, difficulty with concentration, or slight blurring of vision. Such pts have usually sustained a concussion and are expected to have a brief amnestic period.
Two studies have indicated that older age, two or more episodes of vomiting, >30 min of retrograde or persistent anterograde amnesia, seizure, and concurrent drug or alcohol intoxication are sensitive (but not specific) indicators of intracranial hemorrhage that justify CT scanning. It may be appropriate to be more liberal in obtaining CT scans in children, although the risks of radiation must be considered.
In the current absence of adequate data, a common sense approach to athletic concussion has been to remove the individual from play immediately and avoid contact sports for at least several days after a mild injury and for a longer period if there are more severe injuries or if there are protracted neurologic symptoms such as headache and difficulty concentrating.
Injury Of Intermediate Severity Pts who are not comatose but who have persistent confusion, behavioral changes, subnormal alertness, extreme dizziness, or focal neurologic signs such as hemiparesis should be hospitalized and have a CT scan. A cerebral contusion or subdural hematoma is often found. Pts with intermediate head injury require medical observation to detect increasing drowsiness, respiratory dysfunction, pupillary enlargement, or other changes in the neurologic examination. Abnormalities of attention, intellect, spontaneity, and memory tend to return to normal weeks or months after the injury, although some cognitive deficits may be persistent.
Severe Injury Pts who are comatose from onset require immediate neurologic attention and resuscitation. After intubation, with care taken to immobilize the cervical spine, the depth of coma, pupillary size and reactivity, limb movements, and plantar responses are assessed. As soon as vital functions permit and cervical spine x-rays and a CT scan have been obtained, the pt should be transported to a critical care unit. CT scan may be normal in comatose pts with axonal shearing lesions in cerebral white matter.
The finding of an epidural or subdural hematoma or large intracerebral hemorrhage requires prompt decompressive surgery in otherwise salvageable pts. Measurement of ICP with a ventricular catheter or fiberoptic device in order to guide treatment has been favored by many units but has not improved outcome. Use of prophylactic anticonvulsants has been recommended but there is little supportive data.
For a more detailed discussion, see Hemphill JC III, Smith WS, Gress DR: Neurologic Critical Care, Including Hypoxic-Ischemic Encephalopathy and Subarachnoid Hemorrhage, Chap. 330, p. 1777; Ropper AH: Concussion and Other Traumatic Head Injuries, Chap. 457e; and Ropper AH: Coma, Chap. 328, p. 1771; in HPIM-19.