Concussion is a mild traumatic brain injury causing a temporary disruption of brain function from a biomechanical force to the head or neck. This functional disturbance can manifest as confusion, amnesia, dizziness, headache, or brief loss of consciousness, and imaging often shows no structural damage. It is not simply a brain bruise with bleeding and swelling, which reflects a more focal, structural injury, nor does it require direct damage at the moment of impact; concussions can result from rapid acceleration–deceleration and diffuse neuronal disruption rather than a single focal lesion.

An impacted fracture happens when a compressive force drives one end of the bone into the other, jamming the fragments together. This mechanism creates impaction at the fracture site and can shorten the bone, often with little or no displacement of the fragments. It’s the pattern you’d expect from an axial load, such as a fall onto an outstretched hand, where the force pushes the bone ends toward each other. This differs from a spiral fracture, which comes from a twisting force that creates a spiral-shaped break; a dislocation, where the joint surfaces are displaced from one another; and a subluxation, a partial dislocation of a joint. So, the described mechanism best matches an impacted fracture.

Hematoma is the term for a localized collection of blood outside vessels within the tissues. When a blood vessel is damaged, blood leaks into surrounding tissue and pools, forming a lump under the skin that may be tender and change color as blood products break down. This is distinct from edema, which is swelling from fluid in tissue rather than blood, and from ecchymosis, which is skin discoloration (a bruise) caused by blood beneath the skin but not necessarily a discrete pocket of organized blood. Crepitus refers to a crackling sensation from air in soft tissues, not a blood collection. So the described finding fits hematoma.

When intracranial pressure rises, the body responds to preserve blood flow to the brain by increasing systemic blood pressure while the heart rate slows. This hypertensive state with bradycardia is paired with disruption of brainstem respiratory centers, leading to irregular breathing. Together, these signs form the Cushing triad: hypertension, bradycardia, and irregular respirations. It is a late, ominous sign of increased ICP and possible impending herniation. Other terms describe specific breathing patterns or facial signs (for example, Cheyne-Stokes breathing or raccoon eyes) but do not capture the full triad associated with elevated ICP.

In a patient with suspected cervical spine injury, keeping the head and neck in their neutral, immobilized position during airway access is essential to prevent any movement that could worsen a spinal injury. The best approach to achieve this is a two-person technique: one rescuer maintains inline stabilization of the head and neck, while the second rescuer carefully removes the helmet. This setup allows immediate airway access without losing control of the spine, reducing the risk of secondary injury. Having only one person attempt stabilization while removing the helmet increases the chance of movement and compromise. Saying that helmet removal is contraindicated in the field isn’t accurate when airway access is needed and it can be done safely with proper two-person technique. Removing the helmet and neck brace together is not advised because it can disrupt the maintained spine alignment during the removal process.