What is the second impact syndrome brain injury_ - Robert armstrong personal injury attorney north carolina

Suffering a traumatic brain injury (TBI), such as a concussion, is one of the most serious and frightening injuries a victim can experience. The gravity of the injury increases significantly when a second concussion occurs shortly afterward.

Second Impact Syndrome, or SIS, is a result of suffering a second TBI before the brain has adequate time to recover and repair from a previous brain injury. In such an instance, the brain swells rapidly causing dangerous bleeding that can cause death or permanent disability. To make the condition even more precarious, SIS can occur days–and even weeks–after the first concussion is diagnosed.

This article is aimed at helping readers understand SIS, as well as what symptoms to look for, how to prevent a SIS from occurring, and what to do if you or a loved one suffers from SIS.  

Understanding Second Impact Syndrome

TBI’s such as concussions can come from a myriad of sources: car accidents, athletic competitions, or simple slip-and-fall incidents. Thankfully, SIS is a fairly rare syndrome. However, this also means that there are relatively few cases to study for the purpose of understanding how SIS effects the brain, and who is at risk.

When a victim sustains a blow to the head, the body responds with physical and chemical changes that engage to protect the brain from massive swelling. During this healing process the brain is more vulnerable to severe complications if a second impact is sustained. If the injured victim receives a second blow to the head while still suffering from the first injury, the brain experiences further swelling, and death can result in a matter of mere minutes. The cause of death is SIS.  


When a victim suffers from a concussion, typically only minor injuries are sustained. Dizziness, confusion, headache, nausea – these are all symptoms of a concussion. The majority of concussion victims can recover in a matter of hours. However, the symptoms of SIS are more severe and can include:

  • Respiratory failure
  • Severely dilated pupils
  • Unconsciousness
  • Loss of vision
  • Seizures
  • Brain herniation
  • Death

Symptoms of SIS can appear within hours, days or even weeks after the sustained injury. Because SIS is a life-threatening emergency, immediate measures must be taken once symptoms occur.

Preventing Second Impact Syndrome

The most important factor to consider in an effort to prevent SIS is time. Failure to give the brain adequate time to heal after a TBI is vital to preventing SIS. While some victims can fully recover in a matter of days, it may take months for other victims to reach the level at which their brain has fully recovered. In most cases, a qualified medical professional should examine the victim both after the initial injury and in follow up visits afterward.    

One of the most frequent incidents in which victims experience SIS is during sports-related activities. The Center for Disease Control and Prevention (CDC) recommends that once a player has sustained an initial TBI, the player only return to any activities after 24 hours or more have passed. CDC also recommends that once a victim has experienced a TBI, immediate medical examination is performed on the victim to assess cognition, balance, and signs of neurological function deterioration. 

The seriousness and complexity of brain injuries such SIS demands professionals who are at the forefront of evolving medical issues. This includes ensuring that if you or a loved one has suffered from a brain injury, you engage a qualified lawyer that understands the syndrome and can help determine what important steps need to be taken in your case.