About 10% to 20% of people have post-concussion syndrome for more than a month. Symptoms may include headaches, dizziness, fatigue, anxiety, memory and attention problems, sleep problems, and irritability. Rest, a previously recommended recovery technique, has limited effectiveness. A recommended treatment in both children and adults with symptoms beyond 4 weeks involves an active rehabilitation program with reintroduction of non-contact aerobic activity. Progressive physical exercise has been shown to reduce long-term post-concussive symptoms. Symptoms usually go away on their own within months but may last for years. The question of whether the syndrome is due to structural damage or other factors such as psychological ones, or a combination of these, has long been the subject of debate. Cumulative effects
As of 1999, cumulative effects of concussions were poorly understood, especially the effects on children. The severity of concussions and their symptoms may worsen with successive injuries, even if a subsequent injury occurs months or years after an initial one. Symptoms may be more severe and changes in neurophysiology can occur with the third and subsequent concussions. As of 2006, studies had conflicting findings on whether athletes have longer recovery times after repeat concussions and whether cumulative effects such as impairment in cognition and memory occur.Cumulative effects may include chronic traumatic encephalopathy, psychiatric disorders and loss of long-term memory. For example, the risk of developing clinical depression has been found to be significantly greater for retired American football players with a history of three or more concussions than for those with no concussion history.
Surgical complications can develop and include:
Allergic shock due to anesthetics
A paradoxical reaction to a drug
Infection

Cause
The development of TOA is thought to begin with the pathogens spreading from the cervix to the endometrium, through the salpinx, into the peritoneal cavity and forming the tubo-ovarian abscess with (in some cases) pelvic peritonitis. TOA can develop from the lymphatic system with infection of the parametrium from an intrauterine device (IUD). Bacteria recovered from  TOAs are Escherichia coli, Bacteroides fragilis, other Bacteroides species, Peptostreptococcus, Peptococcus, and aerobic streptococci. Long term IUD use is associated with TOA. Actinomyces is also recovered from TOA. Diagnosis
Laparoscopy and other imaging tools can visualize the abscess. Physicians are able to make the diagnosis if the abscess ruptures when the woman begins to have lower abdominal pain that then begins to spread. The symptoms then become the same as the symptoms for peritonitis. Sepsis occurs, if left untreated. : 103  Ultrasonography is a sensitive enough imaging tool that it can accurately differentiate between pregnancy, hemorrhagic ovarian cysts, endometriosis, ovarian torsion, and tubo-ovarian abscess. Its availability, the relative advancement in the training of its use, its low cost, and because it does not expose the woman (or fetus) to ionizing radiation, ultrasonography an ideal imaging procedure for women of reproductive age. Prevention
Risk factors have been identified which indicate what women will be more likely to develop TOA. These are: increased age, IUD insertion, chlamydia infection, and increased levels of certain proteins (CRP and CA-125) and will alert clinicians to follow up on unresolved symptoms of PID.