What is non-penetrating head trauma ?
Concussions
Non-penetrating head trauma may cause three basic types of brain injury. A "
concussion" is any brain injury that causes symptoms or disturbances of mental function. Usually, no findings are discovered on CT scans or MIRs of the brain. A classic example is an athlete "getting his bell rung." The U.S. military requires waiting periods from one month to several years before returning pilots suffering these injuries to flying status, depending on the seriousness and duration of symptoms. The FAA does not have a fixed schedule of observation prior to returning pilots to flight following a concussion. Certification decisions made by the FAA depend on the individual factors surrounding the injury, the resolution of symptoms and possibly neurocognitive testing.
Cerebral contusions
Cerebral contusions are similar to concussions, but there is evidence of bleeding or bruising within the brain tissue. Symptoms are very similar to
concussions. An additional concern to the aeromedical community is that blood in the brain is an irritant that places the pilot/controller at increased risk for seizures. The risk decreases over time and with resolution of the blood in the brain. Observation periods following this type of injury before being cleared to return to flight duties are variable, but generally exceed 1-2 years. EEGs are used to monitor abnormal electrical activity of the brain which may lead to seizures.
Intracranial bleeding
The third type of
non-penetrating brain injury involves bleeding into the fluid filled spaces between the brain and the skull. Depending on the space the blood is found, the injury is termed a subdural, epidural or subarachnoid haematoma. The subdural is the most common and least serious, though it can be life threatening.
Subdural haematomas may not have any symptoms associated, though a
headache, usually dull and diffuse, is the most common symptom. The other two forms of bleeding are immediately life threatening. Symptoms usually include the sudden onset of a
severe headache and loss of consciousness. With intracranial bleeding, immediate concerns are the preservation of life, usually with emergency neurosurgical intervention. The FAA will consider waiver requests following such episodes after recovery is complete if there is no increased risk for recurrence. Observation periods of variable lengths are required following intracranial bleeding before the risk of seizure is low enough for favourable consideration of medical certification.
