[13] The condition is associated with a wide range of non-specific symptoms: physical, such as headache; cognitive, such as difficulty concentrating; and emotional and behavioral, such as irritability.
[18][needs update] Dizziness is another common symptom reported in about half of people diagnosed with PCS and is still present in up to a quarter of them a year after the injury.
[18] Older people are at especially high risk for dizziness, which can contribute to subsequent injuries and higher rates of mortality due to falls.
[19] About 10% of people with PCS develop sensitivity to light or noise, about 5% experience a decreased sense of taste or smell, and about 14% report blurred vision.
[14] Psychological conditions, which are present in about half of people with PCS, may include irritability, anxiety, depression, and a change in personality.
[21][24] Some common symptoms, such as apathy, insomnia, irritability, or lack of motivation, may result from other co-occurring conditions, such as depression.
However, certain risk factors have been identified; for example, preexisting medical or psychological conditions, expectations of disability, being female, and older age all increase the chances that someone will have PCS.
Most common symptoms like headache, dizziness, and sleep problems are similar to those often experienced by individuals diagnosed with depression, anxiety, or post traumatic stress disorder.
[medical citation needed] In many cases, both physiological effects of brain trauma and emotional reactions to these events play a role in the development of symptoms.
[medical citation needed] Studies using positron emission tomography have linked PCS to a reduction in glucose use by the brain.
[medical citation needed] Changes in cerebral blood flow have also been observed as long as three years after a concussion in studies using single photon emission computed tomography (SPECT).
[31] Proponents of the view that PCS has a physiological basis point to findings that children demonstrate deficits on standardized tests of cognitive function following a mild TBI.
[33] A few studies have shown that people with PCS score lower than controls on neuropsychological tests that measure attention, verbal learning, reasoning, and information processing, but issues related to effort and secondary gain can not be ruled out as contributing to these differences.
[36] The development of PCS may be due to a combination of factors such as adjustment to effects of the injury, preexisting vulnerabilities, and brain dysfunction.
[37] Setbacks related to the injury, for example problems at work or with physical or social functioning, may act as stressors that interact with preexisting factors such as personality and mental conditions to cause and perpetuate PCS.
[13] Iatrogenic effects (those caused by the medical intervention) may also occur when individuals are provided with misleading or incorrect information related to recovery of symptoms.
[46][needs update] Cognitive and affective symptoms that occur following a traumatic injury may be attributed to mTBI, but in fact be due to another factor such as posttraumatic stress disorder,[36] which is easily misdiagnosed as PCS and vice versa.
[50] Though no pharmacological treatments exist for PCS, doctors may prescribe medications used for symptoms that also occur in other conditions; for example, antidepressants are used for the depression that frequently follows mTBI.
[31] CBT may help prevent persistence of iatrogenic symptoms[51] – those that occur because health care providers create the expectation that they will.
[54] In situations such as motor vehicle accidents or following a violent attack, the post-concussion syndrome may be accompanied by posttraumatic stress disorder, which is important to recognize and treat in its own right.
Exercise should be implemented as soon as possible after the initial rest period as this lowers the risk of post concussion syndrome (PCS) and overall symptoms.
Education is crucial for concussion patients to stress the importance of being active by engaging in light aerobic exercise, improving sleep habits and reducing stressors as much as possible.
[57] Transcranial low-frequency pulsating electromagnetic fields (T-PEMF) has shown some positive results in treating PCS patients.
[37] Evidence from clinical studies found that high school-aged athletes had slower recoveries from concussion as measured by neuropsychological tests than college-aged ones and adults.
[52] A wide range of factors have been identified as being predictive of PCS, including low socioeconomic status, previous mTBI, a serious associated injury, headaches, an ongoing court case, age and female sex.
[25] The idea that this set of symptoms forms a distinct entity began to attain greater recognition in the latter part of the 19th century.
[71] The controversy surrounding the cause of PCS began in 1866 when Erichsen published a paper about persisting symptoms after sustaining mild head trauma.
[73] In 1961, H. Miller first used the term "accident neurosis" to refer to the syndrome which is now called PCS and asserted that the condition only occurs in situations where people stand to be compensated for the injury.
[43] One complication in diagnosis is that symptoms of PCS also occur in people who have no history of head injury, but who have other medical and psychological complaints.
Couch, Lipton, Stewart and Scher (2007)[75] argue that headaches, one of the hallmarks of PCS, occur in a variety of injuries to the head and neck.