Traumatic brain injury is a hidden epidemic in the US, reaching beyond American football to wounded military veterans and girls’ soccer players. Neurosurgeon Dr Anand Veeravagu outlines concussion’s potentially devastating side effects.

It is all too common for patients to tell me that they have been knocked out while playing sports or in an accident. But the consequences of concussion, or “getting your bell rung” as the disarmingly quaint expression goes, can prove disastrous.

As Chief Neurosurgery Resident at the Palo Alto Veterans Hospital, I’ve treated many of our nation’s service members, some of whom came home with injuries that changed their lives forever.

I will always remember in particular one US Army soldier in my care. Mitch (not his real name) was nearing the end of his deployment in Afghanistan when his convoy was hit by a roadside bomb.

His vehicle’s heavy armour shielded most of his body from the blast and saved his life. But it did little to protect his brain. Despite the very latest in helmet technology, the powerful shock waves of such a blast hitting a vehicle often wreak havoc on soft brain tissue.

At a battlefield hospital in Afghanistan, Mitch underwent an emergency procedure called a de compressive craniectomy, where surgeons removed a 13-in (33-cm) piece of his skull to help make room for uncontrollable brain swelling.