July 25


Second Impact Syndrome: Causes, Symptoms & Treatment

By NeuroHealth Arlington Heights

July 25, 2022

concussion signs, concussion symptoms, second impact syndrome, SIS

Most people know that concussions are a serious risk, but not the deeper details of why that is so. One of the reasons is second impact syndrome, a dangerous condition that is often fatal or causes lifelong disabilities. Any possible concussion or instance of SIS should be treated immediately. Here’s everything you need to know about second impact syndrome, including causes, symptoms, and treatment.

What Is Second Impact Syndrome?

brain testing

Image by National Cancer Institute is licensed with Unsplash License

Second impact syndrome occurs when two concussions occur in close succession. Concussions hinder the brain’s ability to self-regulate pressure and blood volume flow, which can result in acute and severe brain swelling. The pressure can be so high that it forces the brain to push through perforations in the skull, resulting in reduced blood supply to the herniated tissue.

Anyone at potential risk of SIS, such as after head trauma, should seek emergency medical treatment. NeuroHealth Arlington Heights can provide diagnosis, evaluations, and treatment for you or your child after incidents that have or may have caused a concussion.

What Are the Causes of Second Impact Syndrome?

The causes of second impact syndrome could be anything that causes a concussion. The second concussion could happen hours, days, or weeks from the first. The severity of the concussion is not particularly relevant; if two minor concussions occur within a short period, there is still a risk of SIS. The brain cannot operate without appropriate blood flow, and SIS can cause serious impairment or death.

The majority of SIS cases occur in high school from playing high-impact sports such as football, as well as any person with a history of concussions. For those participating in impact-heavy sports and activities, or parents of kids in those activities, proper safety is paramount to prevent concussions and second impact syndrome. Any cases that seem mild but involve the head should still be looked at by a team like NeuroHealth Arlington Heights.

What Are the Signs of Second Impact Syndrome?

Head trauma is often associated with losing consciousness, but the truth is that whether someone falls unconscious directly after a blow to the head, some time afterward, or not at all doesn’t correlate with the danger of the impact or trauma. No matter how the person feels currently, it’s extremely important to catch signs of a concussion or SIS, like:

  • Difficulty concentrating.
  • Dilated pupils.
  • Respiratory problems.
  • Limited or no eye movement.
  • Ringing in ears or hearing problems.
  • Strong headache or sense of pressure in the head.
  • Nausea or vomiting.
  • Difficulties with balance or vision.
  • Sensitivity to light or sound.
  • Problems with concentration or memory.
  • Feeling sick, sluggish, or weak.

If you think someone you know has SIS, or is showing symptoms like the ones above after a blow to the head, please ensure they receive medical attention immediately.

Do You Have to Stay Awake After a Concussion?

It was thought for many decades that people should stay awake after a concussion, as falling asleep risks further damage to the brain. Medical experts today generally agree that it is fine for someone to sleep with a concussion, once they’ve been examined, diagnosed, and treated. SIS, however, is particularly serious, and the priority would simply be to see a physician to learn more.

What Are the Effects of Second Impact Syndrome?

There are two general categories of effects from SIS: immediate danger and long-term effects, although there’s no firm line between them. The long-term effects can involve severe reduction of cognitive, motor, or other neurological functions. Other more immediate issues could fade in and out of severity over the following days, weeks, or months. Seek immediate medical attention if any of the following occur:

  • Headaches worsen or don’t go away.
  • Slurred speech, weakness, numbness, or decreased coordination.
  • Significant nausea or repeated vomiting.
  • Seizures.
  • Unexpected loss of consciousness.
  • Inability to wake up.
  • Any concussion symptoms worsening.

Even seemingly light or “probably nothing” symptoms that have not gone away in a week should be a concern. Anyone who has already had other concussions in the past should also seek treatment quickly, both after the incident and over the following months.

How Is Second Impact Syndrome Diagnosed and Treated?

Whenever there is a suspicion of second impact syndrome or another type of brain injury, the patient must travel to the nearest emergency facility, not urgent care, for a CT scan of the head. The scan is meant to detect the possibility of swelling and/or bleeding in the brain. The goal during this time is to keep the patient stable, with an emphasis on breathing and airway control.

Once the CT scan establishes that there is an increase in intracranial pressure, a physician will determine the best ways to normalize that pressure. These might include:

  • Breathing techniques.
  • Diuresis.
  • Fluid restriction.
  • Blood pressure management.
  • Steroids.
  • Surgery.

A physician will ask how the injury occurred, where it occurred on the head, and what symptoms are present. If possible, an eyewitness of the incident that caused the trauma should be there to give details. After the initial diagnosis and the decision to let the patient go home, any unusual occurrences or returning symptoms are an immediate sign to come back for another visit and re-evaluate.

Preventing Second Impact Syndrome

The most logical approach to SIS prevention is to avoid any concussions by adhering to safety standards. During any kind of sports or other activity that risks impact, using well-maintained, suitable sports equipment and protective gear is a must. Any concussed patient who still shows signs of concussion should not be allowed to return to play or participate in any activities until a physician is confident in their recovery. If someone reports fatigue, headache, disorientation, nausea, vomiting, or feeling “in a fog” during physical activity, they should also stop and see a doctor.

Parents of kids who participate in contact sports should be aware of the indicators of a possible concussion. If you have concerns about your child or yourself after taking trauma to the head, contact the team at NeuroHealth Arlington heights or visit us for diagnosis after an accident. Our clinicians are multilingual and can provide assessments and treatments for all ages, as well as group care. For over 27 years, we’ve been proud to help families and children of Chicago and surrounding cities.

NeuroHealth Arlington Heights

About the author

For over 20 years, NeuroHealth Arlington Heights has been offering neuropsychological and psychological assessments and treatments for people of all ages. These assessments and treatments address Behavioral, Emotional, & Social Issues, Neurocognitive Functions, and Neurodevelopmental Growth.