I'm gonna talk a little bit now about minor head injury
which is a very common problem in emergency medicine.
So in the United States,
we see more than two million Emergency Department visits
per year for head injuries.
Of those, only 300.000 are hospitalized,
a 100.000 are permanently disabled,
and 50.000 die.
So you can see it’s a very, very common disease process,
but it’s only a relatively small fraction of patients
who have bad outcomes
and one of the challenges in head injury management
is to identify the patients
who are at risk for bad outcomes
and manage them appropriately
while not over managing the vast majority of patients
whose clinical course will be benign.
So whose affected by head injury?
This is really more of a disease of men.
There's a two to one male to female predominance.
And it’s a disease of the young.
The most common age group for head injuries
are people under 25 years of age,
although we do see it in older patients as well.
Head injuries are more common among minorities
and falls and motor vehicle collisions
are the most common mechanisms for head injury.
Severe head injuries,
so major traumatic brain injury
with bad outcomes like neurologic disability and death
are much more common at extremes of age.
So we see this among infants and we see it among older adults,
and it's much less common among children
in the school age years and younger adults.
there's really two phases of head injury
and it’s important to understand this
because it helps you understand
the progression of head injury clinically.
So there's your primary head injury
which occurs at the moment of impact
and that's caused by either bleeding or direct neuronal trauma
and this includes the kinds of head injuries
that we're all familiar with
such as epidural and subdural hematomas,
traumatic subarachnoid hemorrhages,
cerebral contusions and diffuse axonal injury.
There's also a secondary phase of head injury
and this secondary phase continues to evolve for hours to days.
This is caused by impaired cerebral blood flow
which can really be the result of local edema
at the site of injury,
small vessel bleeding,
so not big bleeding like you see with the hematoma
but leakage of small vessels.
The inflammatory cascade
and physiologic dysfunction from direct neuronal trauma.
The secondary phase of head injury
is what's responsible for a lot of the cognitive difficulties
that patients will have after even minor head injuries
and it’s important to recognize 'cause long term,
it can actually cause more damage than people realize.
Head injury's severity is stratified
accordingly to the Glasgow Coma Scale or GCS.
So this is what we used to categorize severity
and this is also what helps us determine our work up.
So patients with a GCS on presentation of 13 to 15
are considered to have mild head injuries
and they may or may not need head CTs
based on their risk features.
We'll talk a little bit more about those patients in a moment.
GCS of 9 to 12 is what characterized as moderate head injury
and all of these patients need to have head CTs.
And then severe head injury of our patients
with a GCS of three to eight
and again, all of these patients need brain imaging.
But this mild group is a little bit more complex
because there's only a subset of these patients
who will go on to have adverse outcomes
or require any kind of neurosurgical intervention
and we want to identify all of those patients
without exposing the general population to unnecessary radiation.
So we always, always, always want to CT patients
who have a significantly depressed GCS.
If they're 12 or less,
we're done thinking about it,
we're gonna brain imaging.
If they have any kind of neurologic deficit
including cognitive deficits,
if they have post-traumatic seizure activity,
if they're on anticoagulants
and this is a very important thing to ask every patient
with a head injury whether they take any blood thinners,
and if they're over the age of 65
with any kind of complicating factors
such as loss of consciousness,
amnesia for the events, confusion afterwards,
these are patients who should always be imaged.
These patients have a high risk for deterioration
and they have a much higher risk
for requiring neurosurgical intervention
compared to the more benign group.
So these are patients who are under 65 years of age
with a normal GCS and they're neurologically intact,
they have no deficits,
they have no evidence of seizure activity,
they're not on anticoagulatans,
they have no loss of consciousness, amnesia, confusion.
These are really people who got hit in the head
and their heads might hurt but they're otherwise fine.
These patients should never be imaged,
they're very low risk for developing any kind of complications.
But what do you do with that middle group?
The patients who have a GCS of maybe 14,
maybe they had some loss of consciousness,
maybe they're a little confused.
How do we make decisions about them?
We're gonna talk a little bit
about one of those patients right now.
So our patient is a-54 year-old woman
who comes to the ED with the head injury.
She did in fact have loss of consciousness at the time of injury
and by the time the paramedics arrived to pick her up,
she was dazed.
So she was conscious
but not really fully alert and appropriate.
She is oriented times three so she knows her name,
she knows the date,
she knows where she is,
but she doesn't really remember what happened
and she keeps asking repetitive questions
about what happened and why she's here.
She has no complains except headache,
she does have a little laceration
to her scalp on the right hand side,
and her GCS is 15.
She's able to follow commands,
her eyes are open,
she has a normal speech,
she's just a little bit forgetful
about the events of what happened,
and has this evidence of head trauma on exam.
So what are we gonna do to this patient?
Are we gonna scan her
or are we not gonna scan her?
Twenty years ago,
this patient would have been scanned,
because any patient who is not 100% neurologically normal
would always be imaged.
But we now have some decision rules
that help us decide whether or not the patient
is at high risk for adverse outcomes with the head injury.