normal exam..abnormal head ct

Tuesday, September 6, 2016

Concussion is supposed to be a football and hockey issue, but this weekend it was baseball that reminded us that head injury isn’t limited to “contact” sports. Angels pitcher Matt Shoemaker was hit in the heads with a line drive and though he was not knocked out and had a normal neurological examination, he was not immune from injury. In the real world that mechanism of injury is one of the indications to perform a CT and image the brain.

Mr. Shoemaker cut his forehead but otherwise walked off the field under his own power as he was attended to by the medical staff. Based on being hit by a ball hit at an estimated 105 mph, a CT was done, finding a skull fracture (usually not a big deal) and bleeding inside his head. Press releases weren’t specific about what type of bleeding, but blood in or near the brain is never good.

The skull is a solid box and is mostly filled with brain tissue. If there is swelling or bleeding, there is no place for it to go and the brain may get squashed, which it does not really like. Bleeding in the skull is categorized based on its location.

  • Epidural hematoma or blood clot is located between the brain lining and the skull. This is caused by torn arteries that line the skull
  • Subdural hematoma is located between the lining and the brain tissue and is due to tearing of the bridging veins that travel from the skull to the brain
  • Subarachnoid hemorrhage is located in the space where fluid bathes the brain
  • Intracerebral hemorrhage or hematoma is located within the brain tissue.

ic hematoma

Not all bleeding in the brain needs an operation. Regardless of whether Mr. Shoemaker had an epidural or subdural hematoma, he was watched closely in ICU and had repeated CT scans to monitor the amount of bleeding, whether the clots were enlarging and whether there was pressure being exerted on the brain. Within a few hours, bleeding had progressed and an operation was needed to fix the bleeding issue and prevent brain damage.

There are a variety of guidelines that help decide who might need a CT scan in the first place and who can just be watched. There are all sorts of caveats for each guideline and the purpose is to prevent too many CT scans and the potential radiation risk while not missing significant brain injury. It’s easy to decide to do a CT scan when a head injury victim is not acting normally or has an abnormal physical exam. But Mr. Shoemaker reminds us that one can act normally and still have brain issues. For that reason, “significant mechanism of injury” is an indication to get a CT scan. What is significant? The Ottawa CT head guidelines suggest a couple, including a pedestrian being struck by a motor vehicle, a passenger ejected from a car or falling more than 5 stairs. A 105 mph baseball probably qualifies.

While violent head injuries are self evident, too often injuries can’t easily be appreciated from the sideline and initial symptoms may be shortlived. This week, the NFL Players Association sent out information packets to all its players to teach them about concussion symptoms so that they can help check on their teammates. It’s about time; we called for this to happen in 2011.

And some final food for thought. Mr. Shoemaker has a significant head injury/concussion. Is one big blow enough to cause CTE in the future? Do you need to endure multiple “small” head injuries to cause future chronic brain disease? The joy of not being able to predict the future.




This entry was tagged , , , , ,