All of the following are false of diffuse axonal injury except

Rationale:

A. While this option correctly identifies motor vehicle crashes as the leading cause and falls as the second most common, it incorrectly places assault (gunshot wounds) before sports injuries. Epidemiologically, sports-related injuries occur more frequently than violent causes such as gunshot wounds. This misordering makes the option incorrect.

B. This option significantly misrepresents the frequency distribution. Motor vehicle crashes are the leading cause of spinal cord injuries, not falls. Additionally, sports injuries are less common than both MVCs and falls, so placing them second is inaccurate. This sequence does not reflect real-world data.

C. This option accurately reflects the most common causes of spinal cord injuries in order of frequency. Motor vehicle crashes account for the highest percentage due to high-impact trauma. Falls are the second leading cause, particularly among older adults. Sports injuries, such as diving or contact sports, are less frequent but still significant. Assaults, including gunshot wounds, are the least common among these options.

D. Although falls are a major cause of spinal cord injuries, they are second to motor vehicle crashes in overall frequency. This option incorrectly places falls as the leading cause, making the sequence inaccurate despite correctly placing sports injuries before assaults.

Rationale:
A. In trauma care, a transient responder initially shows improvement in vital signs (such as blood pressure, heart rate, and mental status) after receiving a fluid bolus, typically isotonic crystalloids. However, this improvement is short-lived. As fluids are reduced to maintenance levels, signs of poor perfusion (e.g., hypotension, tachycardia, decreased urine output, altered mental status) reappear. This pattern strongly suggests ongoing internal bleeding or unresolved fluid loss. Transient responders are at high risk for decompensation and usually require rapid escalation of care, including blood transfusion, identification of the bleeding source, and possible surgical or interventional control. This classification helps guide urgency and prioritization in trauma management.

B. This describes a rapid responder, not a transient responder. Rapid responders maintain stable vital signs and adequate perfusion after initial resuscitation, indicating that significant ongoing bleeding is unlikely. These patients can often be monitored with less aggressive intervention.

C. This statement is incomplete and nonspecific. While transient responders may temporarily improve with fluids and even blood products, the defining feature is that the improvement is not sustained. Simply stating that the patient “responds” does not capture the transient nature or clinical significance of their response.

D. The classification is not based on the speed of response but on the durability of the response. A transient responder may initially respond quickly, but the key issue is that the improvement is temporary and followed by deterioration, indicating ongoing pathology such as hemorrhage.