About Concussions & Related Brain Injuries

The Dr. Robert C. Cantu Concussion Center at Emerson Hospital specializes in the evaluation and treatment of three types of concussive brain injuries: 
  • Concussions 
  • Post-concussion syndrome (PCS) 
  • Symptoms of chronic traumatic encephalopathy (CTE)
Here is an overview of each of these conditions:

What is a concussion? 

Concussion comes from the Latin word concussus, which means, “to violently shake.” We define a concussion as a trauma-induced change in mental status, usually resulting from a blow to the head. 

Recognizing concussion symptoms

A concussion can be a hard-to-diagnose injury with a wide range of signs and symptoms, including:


  • Headaches
  • Nausea
  • Vomiting
  • Balance and/or visual problems
  • Dizziness 
  • Sensitivity to light and/or noise
  • Fatigue and/or low energy


  • Depression
  • Nervousness
  • Irritability
  • Panic attacks


  • Difficulty concentrating
  • Troubles with memory
  • Feeling mentally slow or as in a fog that will not lift

Sleep Disturbance

  • Sleeping more or less than usual
  • Trouble falling asleep

What is post-concussion syndrome (PCS)?

Post-concussion syndrome, or PCS, is the name given to concussions that last an unusually long time and challenge patients with unusually intense symptoms. The symptoms of PCS are the same as for concussion, but more severe and longer lasting.

Most concussions resolve in 7 to 10 days, and athletes return to their normal activities in two weeks. Approximately 20% are post-concussion syndrome cases in which symptoms last at least a month.

Because the symptoms—especially sleep difficulties—are so severe and can last for months, some patients develop depression or other psychological disturbances.

What is chronic traumatic encephalopathy (CTE)?

Chronic traumatic encephalopathy, or CTE, is a progressive degenerative disease of the brain found in people exposed over many years to repetitive brain trauma. This trauma can include concussions and/or the multiple subconcussive blows that athletes absorb over a lifetime of participating in sports like hockey and football.

These jolts to the brain can trigger the buildup of an abnormal form of protein called tau. These toxic proteins form plaques that block passageways in the brain, killing brain cells. The process is similar to what happens in the brains of Alzheimer’s patients.

Patients can develop cognitive, behavioral or mood-altering symptoms, becoming upset or violent, having panic attacks, and can suffer from other symptoms, including:
  • Memory loss
  • Confusion
  • Impaired judgment
  • Paranoia
  • Impulse-control problems
  • Aggression
  • Depression
  • Progressive dementia