Which of the following is a secondary damage factor?

• A. Electrolyte imbalance
• B. Contusions
• C. Epidural hematoma
• D. Diffuse axonal injury

Answer: (A)

Secondary damage after traumatic brain injury comes from processes that unfold after the initial mechanical impact and can worsen brain injury over time. Electrolyte imbalance fits this role because it arises as part of the body’s response after the injury and can drive further brain swelling, disrupt neuronal signaling, and increase the risk of complications like seizures or edema. In contrast, contusions, epidural hematoma, and diffuse axonal injury are direct physical injuries caused by the trauma itself, occurring at the moment of impact. They are examples of primary injuries. Keeping electrolytes in balance is a key part of preventing and mitigating secondary brain injury by supporting cellular function, maintaining osmotic stability, and protecting cerebral perfusion.