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.
Post-traumatic amnesia
There is a significant link between individuals currently suffering from PTA and their performance on the Wechsler Adult Intelligence Scale (WAIS). The scores of those currently experiencing an episode of PTA were compared to individuals who had previously suffered a traumatic brain injury resulting in PTA. Those still suffering from PTA performed significantly worse on both the performance and the verbal subscales of the WAIS. Also, people in early stages of PTA have substantial impairment to anterograde memory function. For example, in the case report of a patient referred to as "JL", Demery et al. noted that his memory impairments were so severe following his injury that he had forgotten that he had attended a Major League Baseball game less than 30 minutes after returning to the center where he was being treated.