CM- Neurosurgery Flashcards
What are the 3 main categories for the Glasgow Coma Score?
- Best eye opening [1-4]
- best verbal [1-5]
- best motor [1-6]
What correlates with 1, 2, 3, 4 for best eye opening on the Glasgow Coma Score?
1 = none 2 = to pain 3= to speech 4= spontaneous
What correlates to 1, 2, 3, 4, 5 for best verbal on the Glasgow coma score?
1 = none 2= incomprehensible 3= inappropriate 4 = confused 5 = oriented
What correlates with 1, 2, 3, 4,5, 6 for best motor of the Glasgow coma score?
1= none 2= extensor [decerebrate] 3 = flexion [decorticate] 4 = withdraw to pain 5 = localizes pain 6 = obeys
What is the maximum score that can be achieved on the Glasgow Coma Score? What does this mean for each category?
What is the minimum score on GCS?
What does this mean for each category?
Max score on glasgow is 15
eyes = 4 = spontaneously open
verbal = 5 = oriented
motor = 6 = obeys
Min score is 3
eyes = 1= don’t open
verbal = 1= none
motor =1=none
What GCS scores correlate with:
- severe head injury/coma
- moderate head injury
- mild head injury
- 3 to 8
- 9 to 12
- over 13
Severe head injury on the GCS is 3-8. What is the percent recovery for a person that has a 3? 8?
3 = 4% recovery 8= 50% recovery
What is the difference in treatment for an open skull fracture and a closed skull fracture?
Open - requires operative treatment to prevent infection
Closed - may be elevated if depressed by more than the thickness of the bone. If it is just a linear fracture, it should heal on its own.
What are the 5 major signs associated with a skull base fracture?
- CSF leak through skull base [rhinorrhea, otorrhea] due to dural lacerations
- 7th nerve palsy [facial]
- Battle’s sign - ecchymoses over the mastoid [just behind the ear]
- “racoon eyes” - periorbital ecchymosis
- hemotympanum - blood in the ear
What is the most frequent cause of an epidural hematoma [EDH]?
What is the classic scenario for a person getting an EDH?
What signs will be present on PE?
EDH is caused by skull fracture/trauma that lacerates the middle meningeal artery [or middle meningeal vein, sinus veins]
Presentation:
- hit in the temporal area with brief loss of consciousness
- “lucid interval” where they feel fine
- rapid neurologic deterioration
Physical exam:
- dilated pupil ipsilaterally
- hemiparesis contralaterally
- possible ipsilateral hemiparesis [Kernohan’s phenomenon] if the opposite cerebral peduncle gets compressed onto the tentorial notch
What is treatment for EDH?
Surgical evacuation –> must be done quickly
Describe the appearance of EDH on CT.
- Unilateral bright while elliptoid shape
- attached to bone
- does not cross suture lines
- mass effect pushes brain matter contralaterally
Who is predisposed to a chronic subdural hematoma [SDH]?
Why?
How are CSDH usually formed and what vessels tend to be involved?
Elderly and alcoholics have a predisposition for subdural hematomas because they have atrophic brains.
SDH is caused by tearing of bridging veins due to acceleration/deceleration resulting in bleeding into the subdural space.
“trauma” is often minor and not remembered.
Describe the appearance of chronic SDH on CT.
Because SDH are caused by the tearing of bridging veins, the blood will fill the subdural space slowly
[artery=fast, vein =slow]
- slow filling allows membrane formation on the inner and outer surface of the clot which liquifies [black on the CT].
- outer membrane is vascularized and repeat bleeds occur [brighter white]
What leads to the formation of an acute subdural hematoma [SDH]?
What differentiates it from a chronic subdural hematoma on CT ? What differentiates it from epidural hematoma on CT?
Tearing of bridging veins as the brain moves within the skull due to acceleration/deceleration OR from laceration of a cortical vein/artery.
It is is associated with significant parenchymal damage and has worse outcome. Treatment is surgical.
On CT you see bright white filling the brain cavity [different from the dark and light spaces of chronic]. It is able to cross sutures likes [different from epidural hematoma]
What is a contusion/intracerebral hematoma?
What are the 2 main types?
What causes each type and where are they commonly seen?
Direct trauma to the brain parenchyma:
- Coup - injury occurs at the point of impact [where the brain hit the skull]. It is usually caused by direct impact applied to a non-moving skull [hammer, bat, etc]
- Contre-coup is injury that occurs opposite the site of impact and is usually due to a motile skull striking a fixed surface [falling backward and hitting your head on a table]. For this reason, most contre coup are on the frontal and temporal lobes because of an occipital blow
What is diffuse axonal injury?
How does this occur?
What would you see on microscopy?
Diffuse axonal injury is shearing injury to white matter tracts due to acceleration/deceleration.
- lateral/coronal acceleration is most important with saggital movement producing less damage.
On microscopy, you would see spheroids which are bundles of the sheared axons.