JohnZ,

Welcome to NeuroTalk.

There are two issues related to second impacts. The one that scares people is called Second Impact Syndrome. This is when a person suffers a severe concussion and before that concussion heals and the brain restores its ability to control blood and fluid pressure, a second serious concussion is suffered. This can cause a run away problem with blood and fluid pressure in the brain that can be dangerous. This is very rarely a risk after a garden variety concussion.

The more common issue is increased sensitivity or increased symptoms from a concussion. A second concussion of the same impact intensity could result in more severe symptoms or a less severe concussion will cause the same intensity as the first.

People tend to get caught up in anxiety about any head impact or quick movement and think it is a concussion when the bump is often not even enough to be considered a sub-concussive impact. The movie Concussion from a few years ago has caused a lot of anxiety since it addresses sub-concussive impacts.

The problem with this anxiety is it is not based in reality. Even sub-concussive impacts are not a risk individually. It takes many over a short period to be a risk.

What is more common is upper neck injuries and vestibular injuries (some call them vestibular concussions) that can cause symptoms such as head aches and dizziness. These symptoms can trigger anxiety that can cause one to obsess that they are fully concussed and the mind is triggered into a flash back of symptoms from the prior serious concussion.

The neck may be traumatized and need some care. In many, the subtle neck injury from a concussion takes much longer to heal than the actual concussion so it is easily triggered into a relapse of symptoms.