Neuro Trauma

Cerebral Contusions

• Surface level insult to the cortical gray matter and some white matter deep to the affected area if enough force

• Typically bilateral and multi-focal (90% of cases)

• Will see new lesions, enlargement of lesions and hemorrhage typically within 24-48 hours

  • > 95% of cases will have extra-axial hemorrhage, most commonly SAH

• Will have residual gliosis/encephalomalacia after healing

• Most common location is anterior frontal lobes followed by temporal lobes

Le Fort Classification

• Fractures of midface which result in separation of midface from skull base

• Pteryoid plates and sphenoid bone always involved

• Le Fort 1

  • Horizontal maxillary fracture separating teeth from rest of face

  • Key point - only one to involve anterolateral aspect of nasal fossa

• Le Fort 2

  • Pyramid shaped fracture

  • Key point - only one to involve orbital rim

• Le Fort 3

  • Key point - only one to involve zygomatic arch

    • Increased risk of temporalis muscle impingement

  • Highest risk of CSF leak

Kernohan Notch

• Cerebral crus = white matter tracts at anterior aspect of cerebral peduncles

• The Kernohan notch phenomenon occurs when there is a large midline shift which results in compression of the opposite cerebral peduncle (and therefore cerebral crus) which then results in a contralateral neuro deficit (because of the decussation), so

• Expansile right sided lesion —> causes compression of left sided cerebral peduncle —> which causes a right sided deficit

Diffuse Axonal Injury

• Caused by shearing forces

• Multiple scattered hyperdense/hyperintense areas throughout brain in setting of trauma

• 3 Stages

  • Stage 1 - lesions at white matter/gray-white junction

  • Stage 2 - lesions in corpus callosum (+/- stage 1 findings)

    • Typically in splenium and body of CC

  • Stage 3 - lesions in brainstem (+/- stage 1 & stage 2 findings)

Hyperflexion spine injury

• Widening of the posterior disc space

• Widening of space between spinous processes

• Focal kyphosis

• Widened, jumped, perched facets

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