0:00

Usually, based on the clinical information,

0:03

one knows whether the lesion that one is evaluating is at

0:08

the coup or the contrecoup portion of the anatomy.

0:12

Clearly, if the patient's head strikes a windshield

0:16

or a steering wheel,

0:17

or if someone gets punched in the occipital

0:20

region or the frontal region,

0:22

we know where the initial direct impact is,

0:25

and that is what is termed the coup injury.

0:28

Sometimes, if the patient is unconscious,

0:30

we may not know exactly whether the patient fell forward

0:34

and landed on the frontal region or fell

0:37

and landed in the occipital region,

0:40

and sometimes this can be used for either medical

0:43

legal purposes or for criminal investigations.

0:47

In general,

0:48

the coup injuries are ones in which one sees the swelling

0:52

of the scalp or the subgalea region,

0:55

or where one has the initial fracture due to that impact.

1:01

However, epidural hematomas, subdural hematomas,

1:05

subarachnoid hemorrhage,

1:07

and intraventricular hemorrhage

1:09

can occur coup or contrecoup.

1:13

Similarly, contusions, as you heard previously,

1:17

can occur coup or contrecoup,

1:19

but they tend to favor the contrecoup

1:22

portion of the traumatic injury.

1:25

Also, with the initial injury,

1:28

one may have injuries to the blood vessels,

1:30

and these may be the indications for CTA to look for

1:35

dissections of intracranial vessels or dissections

1:38

of neck vessels, as the case may be.

1:41

For today,

1:42

we're going to be talking merely

1:43

about intracranial pathology,

1:45

and therefore, dissections of middle cerebral artery would

1:50

be the most common location for an intracranial

1:54

dissection from trauma.

1:56

You can have pseudoaneurysms as

1:58

the blood vessels are ripped,

1:59

and these may occur both in the neck

2:02

as well as intracranially.

2:05

Contrecoup injuries will not include the scalp

2:08

or the fracture sites,

2:10

and they will include, however,

2:13

your epidural hematomas and subdural hematomas

2:16

and subarachnoid hemorrhage.

2:17

Most contusions and parenchymal hematomas occur contrecoup,

2:22

and you may also see the effects of the pseudoaneurysm

2:28

bleeding, etc., in the contrecoup fashion.

2:31

This is a series of CT scans in which one can see the

2:37

scalp swelling overlying the anterior left frontal region.

2:42

Here on these images,

2:44

we see, superficial to the calvarium, swelling of the scalp

2:48

on multiple images,

2:50

this would define the coup portion of the injury.

2:54

We would look on bone windows to see whether

2:57

or not there was a fracture of the

3:00

calvarium underlying the soft tissue swelling.

3:03

You'll note also that there is a focus of hemorrhage along

3:09

the anterior surface of the left frontal lobe,

3:13

where there is a small contusion of the cortex

3:17

of the left frontal lobe.

3:20

However,

3:21

you'll also note that the patient has a lesion opposite from

3:26

direction of the coup injury in the

3:30

right parietal occipital region,

3:32

which is actually larger than the coup injury.

3:36

And this is, again, what I would characterize as a

3:39

parenchymal hematoma. And this is a contrecoup injury.

3:44

It has some surrounding edema.

3:46

And this surrounding edema will increase over time and

3:50

lead to greater mass effect over the course of the initial

3:54

three to five days after a traumatic injury to the brain.

3:58

So, I think this is a nice example of how one has evidence

4:02

of both coup, as well as contrecoup injury in a patient.

4:08

One other thing to highlight,

4:11

and that is the density of the posterior

4:14

falx in this patient.

4:16

So, one sees that the falx is slightly hyperdense

4:22

and it extends to the superior sagittal sinus.

4:25

This is a small subdural hematoma along the posterior falx.

4:31

And you see that contrasted with the normal

4:34

appearance of the falx further anteriorly.

4:38

This is another example of a coup contrecoup injury.

4:42

Here we have a brain window and a bone window

4:48

of the same slices.

4:50

One sees the scalp swelling of the coup injury.

4:54

And in this instance,

4:55

one also sees an underlying fracture

4:58

if I remove my arrowhead,

5:01

where the patient has right temporal bone fracture

5:05

of the squamosal portion of the temporal bone.

5:08

However,

5:09

after looking at the coup portion of the abnormality,

5:14

one should of course look contrecoup.

5:16

And what does one see?

5:17

Contracoup? You see a contusion.

5:20

So why am I calling this a contusion?

5:22

It's not as dense and well defined

5:24

as what I would call a hematoma.

5:26

It's a little bit of a bruise to the brain, and you

5:29

do see some blood products, but in addition,

5:31

there's some edema from these little micro

5:34

hemorrhages in the left temporal lobe.

5:37

So, another example of a coup contracoup injury with soft

5:41

tissue swelling and fracture coup and

5:43

a parenchymal contusion contrecoup.