Post-concussion syndrome
Post-concussion syndrome, also known as postconcussive syndrome or PCS, is a set of symptoms that may continue for weeks, months, or a year or more after a concussion – a mild form of traumatic brain injury (TBI). The rates of PCS vary, but most studies report that about 15% of individuals with a history of a single concussion develop persistent symptoms associated with the injury. A diagnosis may be made when symptoms resulting from concussion last for more than three months after the injury. Loss of consciousness is not required for a diagnosis of concussion or post-concussion syndrome.
List of NFL players with chronic traumatic encephalopathy
As the families of many deceased players wish to keep their medical information private, the following list is incomplete. A brain injury study conducted at the Boston University School of Medicine showed that 33 of 34 players tested post-mortem showed clear signs of CTE, and additional players have so far been confirmed with CTE separately. A new list released in November 2016 mentions CTE in 90 of 94 brains of former and deceased NFL players. In July 2017, a new study showed that 110 of 111 brains examined showed signs of CTE.
Included in the list are players diagnosed with amyotrophic lateral sclerosis (ALS) who were never tested "post-mortem" for CTE but whose history appears consistent with CTE. A typical diagnosis of ALS has primarily been based on the symptoms and signs the physician observes in the patient and a series of tests to rule out other diseases and therefore, prior to the discovery of CTE as a phenomenon in ex-American football players, many CTE cases were diagnosed as ALS. The testing of CTE in deceased ex-NFL players began only after the disease was first diagnosed, in 2002, in the brain tissue of Mike Webster. After then, testing became common practice only gradually. A cohort mortality study run by the National Institute for Occupational Safety and Health (NIOSH) examined 3,349 NFL players who played at least five full seasons from 1959 to 1988. Findings showed that while NFL players lived longer than the average American male, the risk of death associated with neurodegenerative disorders was about three times higher among the NFL cohort. The risk for death from Alzheimer's disease and ALS were about four times higher among the NFL cohort.