Concussion

A concussion is a mild traumatic brain injury caused by a blow, jolt or sudden movement of the head that temporarily disrupts normal brain function.

Symptoms can appear immediately or over hours and include headache, dizziness, confusion, nausea, sensitivity to light and noise, memory gaps, slowed thinking, irritability and sleep changes. Loss of consciousness occurs in only a minority of cases. Sports collisions, falls, vehicle crashes and assaults are common causes, and repeated concussions, especially before recovery is complete, carry greater risk.

Diagnosis is clinical, using symptom checklists, cognitive and balance testing and neurological examination; CT or MRI scans are usually normal and are ordered mainly to exclude bleeding or fracture. Standard care involves a brief period of relative rest followed by gradual, monitored return to activity. Cannabidiol has mechanistic and animal research related to brain injury, but randomized human trials in concussion are lacking.