Swann, McCarter Later investigation of head injury

Most head injured patients arrive in the accident and emergency (A&E) department within a few hours of the injury. This article concerns the investigation of a group that has received less attention: those whose first attendance is delayed, who reattend, or develop complications after a period of observation. Delay in the initial presentation or unplanned return to the A&E department after head injury can occur for a variety of reasons. The abuse of alcohol or drugs may lead to signs of an injury being noted only after the patient wakes up or is found still in coma long after the effects of the agent should have cleared. Sometimes seemingly trivial injury leads to attendance some hours, days, or even weeks later because of persisting or worsening symptoms. Studies in South Africa, England, and Scotland' showed that about 2-3 % of A&E patients reattend after being sent home with an apparently minor head injury (only 0.2% of the total new A&E attenders). Most of these have responded to advice given at the time of discharge and have developed symptoms such as headache, dizziness, or vomiting prompting reattendance within two weeks of the injury. In Scotland in 1979 the annual incidence of an intracranial haematoma undergoing surgery was shown to be 4.5 per 100 000 population.4 Data from a regional neurosurgical unit indicate that one fifth of these are pure extradural haematomas and over two thirds are intradural haematomas, which is the commoner finding at all stages after injury. A report in 1980 showed that over one quarter of surgical intracranial haematomas received surgery after three days (table 1).5 This pattern may have changed with the increased use of computed tomography but intradural haematomas (subdural and intracerebral) still tend to present later than extradural haematomas. Patients with chronic subdural haematoma (a subdural collection of dark fluid occurring at three weeks after injury or later) reach neurosurgical units at the annual rate of one per 100 000 population.6 7