Importantly, the influence of MTBI on these measures of impairment was not significant after controlling for the effects of PTSD and depression.59 This conclusion was supported in a second large-scale military study.92 Similarly, a large-scale study of civilians found that impaired functioning was not increased by the presence of MTBI; however, there were very significant functioning deficits if a patient sustained a psychological disorder in conjunction with the MTBI.78 This convergent evidence Inhibitors,research,lifescience,medical points to physical, social, and occupational impairment being strongly related to psychological factors occurring after trauma

exposure, such as PTSD and depression, rather than the presence of MTBI. Postconcussive syndrome and PTSD The issue of postconcussive Inhibitors,research,lifescience,medical syndrome is a vexed one, both in terms of its definition and its purported causes. It is also an issue that intersects with symptoms of PTSD. PCS is generally defined as a syndrome that involves headache, dizziness, fatigue, sensitivity to light or sound, sleep disturbance, and concentration difficulties.93 The definitions of PCS vary, and generally overlap somewhat with symptoms of PTSD. For example, Inhibitors,research,lifescience,medical the International Classification of Diseases (ICD-10) 26 stipulates that PCS is defined by headaches, dizziness, general malaise, fatigue, noise intolerance, irritability, emotional lability, depression, or

anxiety, concentration or memory difficulty, sleep disturbance, reduced tolerance to alcohol, and a preoccupation with these symptoms and fear of permanent brain damage. The Appendix of the DSM.-IV 4 describes PCS as fatigue, sleep disturbance, headaches, dizziness, irritability, anxiety or depression, changes in personality, and apathy. These Inhibitors,research,lifescience,medical descriptions clearly overlap with common symptoms Inhibitors,research,lifescience,medical of post-traumatic stress, and represent differential diagnosis problems insofar as how one attributes these symptoms to PCS or PTSD. Recent evidence is highlighting that symptoms described as PCS are common

in many populations, and actually reflect a diffuse collection of frequently experienced sensations. In healthy individuals, headaches, sleep difficulty, irritability, and memory failures are relatively common in daily life.97-98 One study found that 72% to 79% of healthy adults reported Idoxuridine at least three or more PCS symptoms; further, a significant minority of find more subjects met DSM-TV (14.6%) or FCD-10 (12.5%) criteria for PCS.99 Interestingly, these observed rates of PCS in non-MTBI are comparable to the rates noted in TBI populations, highlighting the fact that PCS are not unique to TBI. There has been much debate over the extent to which persistent PCS develops as a result of neurological damage,100 psychological distress,101 or a combination of both.102 One recent study that assessed PCS in both MTBI and non-MTBI injured patients found that comparable proportions of patients reported PCS (MTBI: 40%; no-TBI: 50 %).