REVIEW – August 2018

Mild traumatic brain injury

Authors: Väino Sinisalu 

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Every year 50 million individuals sustain traumatic brain injury worldvide and approximately 73% of them are classified as mild traumatic brain injury mTBI), also classified as concussion. The mTBI is defined as traumatically induced physiological disruption of the brain function manifested by at least one of the following: 1) any period of loss of consciousness; 2)any loss of memory of events occurring immediately before or after the accident; 3) any alteration of the mental state at the time of the accident; 4) focal neurological deficit that may or may not be transient. The severity of the injury does not exceed the following: loss of consciousness for 30 minutes or less; posttraumatic amnesia not longer than 24 hours; an initial Glasgow Coma Scale of 13–15 after 30 minutes. Currrent brain imaging methods (CT, MRI) cannot diagnose concussion. The purpose of CT is to assess brain haemorrhage or contusion. For patients with mTBI, physical and cognitive rest lasting 3–5 days of injury is recommended, followed by a gradual resumption of physical and cognitive activities depending on tolerance. In most patients with concussion symptoms resolve in two weeks, however, according to recent studies, up to 84% of the patients feel emotional distress beyond 2–4 months of injury. Persisting symptoms beyond 6 months of injury are seen in 5–6% of the patients. Ongoing research is aimed at finding biomarkers for concussion in the blood and modalities of MRI to visualise miroscopic damages in the brain tissue.