This is the most frequently encountered clinical situation. Roughly, two degrees of disturbed function can be recognized within this category. In one, the patient only stunned momentarily, “saw stars,” or was briefly disoriented. This injury is insignificant when judged in terms of life or death and brain damage, although, as we point out further on there is still the small possibility of a skull fracture or the later development of an epidural or subdural hematoma. Moreover, some patients are liable to a troublesome posttraumatic syndrome consisting of various combinations of headache, giddiness, lack of mental clarity, fatigability, insomnia, and nervousness that can appear soon after or within a few days of the injury. This problem is discussed in a later section. In the instance of consciousness that was temporarily abolished for a few seconds or minutes, recovery may already be complete or the patient may be in one of the stages of partial recovery described earlier when first encountered by the physician. Even though mentally clear, there is amnesia for events immediately preceding and following the injury. The latter produces a circumscribed confusional state that is usually confined to inattention and may be ongoing when the patient is first examined. It is characterized by a dazed appearance and repetitive questions from the patient about the circumstances that led to his being found.
In most such mild cases, a brief assessment for mental clarity, weakness, ocular abnormalities, and Babinski signs is appropriate, but there is little need of extensive neurologic consultation and hospitalization is not required, provided that a responsible family member is available to report any change in the clinical state. In only a small group of these patients, mainly in those who are slow in regaining consciousness or who have severe headache, vomiting, or a skull fracture, is there significant risk of intracerebral hemorrhage or other delayed complications. There should also be caution if there is any chance of neck injury.
Whether to obtain imaging of the head routinely in such patients is an unresolved problem. In our litigious society, the physician is inclined to obtain a CT scan. If imaging shows no subarachnoid blood (a common finding) or intraparenchymal clot or contusion, and the patient is mentally clear there is little chance of developing an extradural hemorrhage. The presence of a fracture may increase these odds but most studies, such as the one by Lloyd and colleagues, have found that the presence of a skull fracture in children proves to be a relatively poor indicator of intracranial injury. The exception is a fracture through the squamous bone and the groove of the middle meningeal artery, which represents a risk for arterial bleeding and epidural hemorrhage.
With the current focus on the cost-effective use of ancillary studies, criteria that justify obtaining a cranial CT following minor forms of head trauma have been developed as discussed in the next paragraph. We have generally advised a CT in cases of head injury that was associated with loss of consciousness (more than 1 min), severe and persisting headache, nausea and vomiting, a confusional state, and any new, objective neurologic signs, but these are admittedly arbitrary criteria. The CT scan may be particularly important in elderly patients with minor head trauma, in whom the presence of an intracranial lesion (mainly subdural hematoma) may not be predicted by clinical signs and, of course, imaging may be advisable if the patient is taking anticoagulants or antiplatelet agents of any type beyond small doses of aspirin. In children, it may be advisable to perform the scans more liberally. This is underscored by the results of a study of 215 children with minor head trauma conducted by Simon and colleagues: 34 children with no known loss of consciousness and a Glasgow Coma Scale score of 15 nonetheless displayed intracranial lesions, 3 of whom required surgery.