A brain concussion is a still incompletely defined syndrome of traumatic brain injury (TBI) that causes a spectrum of symptoms without evident structural damage to the brain. A headache, cognitive deficits, emotional instability, sleep disturbances, and an overall change in mental state after trauma are highly suggestive signs of a concussion. Through several tests, the diagnosis is primarily made on clinical grounds, whereas imaging studies may be used to rule out more severe forms of injury.
Because the definition of a concussion denotes a mechanical injury of the brain without visible structural damage on imaging studies, the physician makes the diagnosis solely on clinical criteria and the findings from the clinical presentation    . Head trauma prior to the onset of symptoms is a mandatory step in the development of a concussion and headaches, often accompanied by dizziness, are described as the two most frequent findings in these individuals    Nausea, vomiting, and changes in the state of consciousness can be encountered as well   . Furthermore, a concussion is known for producing various neurological changes that are primarily related to behavior and cognition - emotional lability, depression, and irritability are main patterns of mood disorders, whereas forgetfulness, memory loss, transient amnesia, reduced reaction times, and deficits in attention might also be present     . Visual impairment and a sense of numbness are reported by some studies, whereas altered sleep may eventually appear in the form of insomnia    . In rare cases, convulsions and significant motor deficits right after head trauma can constitute the clinical picture of a concussion  .
The diagnostic workup of cases in whom a concussion is suspected must encompass a detailed history and a thorough physical examination   . The physician must determine the exact events that preceded the onset of complaints and exclude their presence prior to head trauma, as the clinical presentation could be similar to exercise-induced fatigue and consequent headaches or migraines  . If the initial injury occurred days or weeks ago, patients should be asked about their sleeping patterns, whether they experience memory loss, or if new-onset epilepsy may have developed . The physical examination is crucial for assessing the level of consciousness and awareness of the patient, but also for evaluating the cognitive status and other neurological insults that might have occurred. Because a concussion is currently classified as a form of traumatic brain injury (although this topic has become a matter of significant discussion) , imaging studies need to be employed in order to rule out more serious damage. Apart from the examination of the skull, plain radiography provides little benefit in patients with a suspected concussion, which is why computed tomography (CT) is used as the cornerstone of diagnostics   . Magnetic resonance imaging (MRI) and MR spectroscopy are used as even more advanced methods to reveal pathological changes in the brain that are not visible on CT   .