The question of the cause or causes of PCS has been heavily debated for many years and remain controversial. It is not known to exactly what degree the symptoms are due to physiological changes or to other factors, such as pre-existing psychiatric disorders or factors related to secondary gain or disability compensation. The subjectivity of the complaints complicates assessment and makes it difficult to determine whether symptoms are being exaggerated or feigned. PCS may also be exacerbated by psychosocial factors, chronic pain, or an interaction of some or all of these. The majority of experts believe that PCS results from a mix of factors, including preexisting psychological factors and those directly relating to the physical injury. It is not known what causes PCS to occur and persist, or why some people who suffer a mild traumatic brain injury later develop PCS while others do not. The nature of the syndrome and the diagnosis itself have been the subject of intense debate since the 19th century. 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 suffer PCS. Physiological and psychological factors present before, during, and after the injury are all thought to be involved in the development of PCS. Some experts believe post-concussion symptoms are caused by structural damage to the brain or disruption of neurotransmitter systems, resulting from the impact that caused the<unk> . Others believe that post-concussion symptoms are related to common psychological factors. 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. In many cases, both physiological effects of brain trauma and emotional reactions to these events play a role in the development of symptoms. Physiological Conventional neuroimaging studies of the brain following a<unk>  are typically normal. However, studies have found some subtle physiological changes associated with PCS using more novel imaging modalities. Studies using positron emission tomography have linked PCS to a reduction in glucose use by the brain. Changes in cerebral blood flow have also been observed as long as three years after a<unk>  in studies using single photon emission computed tomography (SPECT). At least one study with functional magnetic resonance imaging (fMRI) has shown differences in brain function during tasks involving memory after mild traumatic brain injury (mTBI) although they were not examining PCS specifically. Not all people with PCS have abnormalities on imaging, however, and abnormalities found in studies such as fMRI, PET, and SPECT could result from other comorbid conditions such as depression, chronic pain, or posttraumatic stress disorder (PTSD). 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. 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. Recovery as measured by scores on cognitive tests frequently do not correlate with resolution of symptoms; individuals diagnosed with PCS may still report subjective symptoms after their performance on tests of cognitive functioning have returned to normal. Another study found that although children with PCS had poorer scores on tests of cognitive functioning after the injury, they also had poorer behavioral adjustment before the injury than children with no persistent symptoms; these findings support the idea that PCS may result from a combination of factors such as brain dysfunction resulting from head injury and preexisting psychological or social problems. Different symptoms may be predicted by different factors; for example, one study found that cognitive and physical symptoms were not predicted by the manner in which parents and family members coped with the injury and adjusted to its effects, but psychological and behavioral symptoms were. Brain inflammation is suggested to play a role in post-concussive syndrome. Psychological It has been argued that psychological factors play an important role in the presence of post-concussion symptoms. 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. 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. In one study, levels of daily stress were found to be correlated to PCS symptoms in both concussed subjects and controls, but in another, stress was not significantly related to symptoms. 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. This information may cause people to focus and dwell on the idea that their brains are permanently damaged,. It appears that even the expectation of symptoms may contribute to the development of PCS by causing individuals with mTBI to focus on symptoms and therefore perceive them to be more intense, to attribute symptoms that occur for other reasons to the injury, and to underestimate the rate of symptoms before the injury.
complications of Concussion
complications of Motion sickness
complications of Coma
complications of Hearing loss
medical cause of Hearing loss
complications of Stroke
medical cause of Lightheadedness
symptoms of Vertebral artery dissection