Edema after CNS Trauma: A Focus on Spinal Cord Injury

Edema, characterized by increased water content, is a common observation following spinal cord injury (SCI). It can worsen the initial damage to the affected tissue. The exact mechanisms are still not fully understood, resulting from mechanical damage and inflammation that affects the blood spinal cord barrier and cellular electrolyte balance. This review summarizes the existing knowledge about how edema forms in the spinal cord versus the brain. It emphasizes understanding the specific edema mechanisms following SCI. Also, it outlines the time-related progression of edema after spinal cord damage and presents an overview of possible treatment approaches that focus on preventing edema formation post-SCI. Edema formation after SCI involves interdependent factors such as disruption of the blood spinal cord barrier, increase in capillary permeability, deregulation in hydrostatic pressure and electrolyte imbalance. These factors contribute to water uptake in the cells.

• 1
  Edema formation is one of the first events of the acute phase of spinal cord injury (SCI) and its mechanisms are similar in the brain and spinal cord, but structural and tissue-specific differences can affect edema formation in these two regions.
• 2
  The spinal cord has a larger subarachnoid compartment and a physiological epidural space compared to the brain, influencing post-trauma tissue pressure. Additionally, the arrangement of collagen and elastin fibers are more oriented in the spinal cord’s dura matter than in the brain’s.
• 3
  The blood–spinal cord barrier (BSCB) is more permeable than the blood-brain barrier (BBB) due to differences in tight junction proteins, affecting immune cell infiltration and the spread of pro-inflammatory molecules. This makes the spinal cord more sensitive to secondary events than the brain, especially in the first 24 h after the injury.