Neuro trauma Flashcards
Location of diffuse axonal injury bleeds in order ?
- Subcortical white matter
- Posterior limb internal capsule
- Corpus callosum
- Dorsolateral midbrain
Common causes of subarachnoid hemorrhage
- Traumatic
- Aneurysm rupture
AVM, perimesencephalic venous hemmorhage, ruptured dissecting aneurysm, hypertensive hemmorhage, cerebral infarction with reperfusion hemmorhage, anticoagulation therapy, blood dyscrasia, eclampsia, spinal vascular malformation
Segments of the carotid
1 - Cervical Segment 2 - Petrous 3 - Lacerum 4 - Cavernous 5 - Clinoid 6 - Ophthalmic (supraclinoid) 7 - Communicating (terminal)
Segments of Vertebral Artery
V1 - origin to transverse foramen of C6
V2 - transverse foreman of C6 to transverse foreman of C2
V3 - C2 to dura
V4 - Dura to confluence of basilar artery
Risk factors for dissection
Fibroelastic thickening Fibromuscular hyperplasia Cystic medial degeneration Marfan Syndrome Ehlers-Danlos Homocystinuria Loeys-Dietz Syndrome Syphilis
Most common location for intracranial dissection
Supraclinoid carotid
What are the types of occipital condyle fractures and which is unstable?
1 - impaction injury with no displacement - stable
2 - skull base fracture extending through occipital condyle - stable
3 - avulsion fracture - unstable due to tension on alar ligament
What is a Jefferson Fracture?
Burst fracture through C1 fracuture bilateral posterior arch or single unilateral anterior arch.
Results in outward displacement of lateral masses.
What are finding of posterior ligamentous complex instability on CT?
Inferred on CT by: Splaying of spinous processes avulsion fracture of superior or inferior aspects of contiguous spinous processes Widening of facet joints Empty/Naked facet joints perched or dislocated facet joints vertebral body translation or rotation
What is the classification of Odontoid fractures and their stability?
Type I - tip of dens. uncommon. Fuse well with immobilization. Stable.
Type II - Fracture at the Dens-body junction. Most common. Risks for instability - Age >50, >6mm displacement, comminution or splinter fragments.
Type III - Fracture line extends through cancellous portion of C2 body. Potentially unstable. Heal with immobilization usually.
What is a hangman fracture and mechanism?
Bilateral traumatic pars interarticularis fracture resulting in spondylolysis.
Mechanism either compressive hyperextension or distractive flexion.
Classification of Hangman #’s
Type 1 - 11 degrees, >2mm translocation. variable stability
Type 2a - severe angulation without translocation. intact anterior longitudinal ligament.
Type 3 - bilateral facet dislocation - UNSTABLE
What is atlanto-axial subluxation?
Anterior facet of C1 fixed on facet of C2 causing impaired rotation.
Types of blunt cervical vascular injuries
Minimal intimal injury Raised intimal flap Dissection with intramural hematoma Occlusion Pseudoaneurysm Transection with active hemorrhage Arteriovenous fistula
What is a chance fracture
Vertebral fracture through all 3 columns. Most common at thoracolumbar junction. Mechanism commonly flexion and distraction.
What are the buttresses of the face? 3 horizontal and 3 vertical
Horizontal - Superior orbital rim, inferior orbital rim, alveolar ridge
Vertical - nasomaxillary, zygomaticomaxillary, pterygomaxillary
Naso-orbital ethmoid fracture includes
Intersection of multiple bones - maxillary, lacrimal, nasal, and frontal. Fractures include the inferior orbital rim, medial orbital rim, nasal bones and ethmoid.
What are the 4 components of a quadripod fracture of the zygomaticomaxillary complex?
zygomaticofrontal, zygomaticomaxillary, zygomaticotemporal, and zygomaticosphenoid
Definition of LeFort Fractures
All must involve the pterygoid plates. And disrupt the pterygomaxillary buttress
I - horizontal plane detaches hard palate/ all walls of maxillary sinus
II - pyramidal spares medial walls of maxillary sinus. Fracture through medial and inferior orbital rims and zygomaticomaxillary buttress. Dissociate mid face from skull
III - Complete midface dissociation. Fracture through the zygomatic arch
What is injured in a cervical hyperextension-rotation injury
Below C2. Usually C6/7
Asymmetric injury of the posterior column
Can present with radiculopathy
What is injured in a cervical hyperflexion injury?
Fracture of neural arch and widening of anterior portion of disc space
mid-lower c-spine
What is the difference injuries in cervical hyper flexion injury with compression vs distraction
Compression - forced flexion with axial loaded spine, primary injury to anterior and middle columns
Distraction/Shearing - failure posterior then middle columns
What is the differential for Odontoid fracture?
Os Odontoideum - odontoid replaced by ossicle with no continuity to C2 body
Pathologic C2 Fracture
Rheumatoid - C1/C2 subluxation
Ossiculum Terminale Persistens - confusion of ossiculum terminal to body of dens beyond 12th year of age
Congenital variation - 3rd occipital condyle, bony peg of anterior lip of foramen magnum(simulate type 1 fracture)
