What is the difference between concussion and contusion?
concussion:
- mild force
- no morhologic findings in brain
contusion:
- more severe signs
- possible complications leading to coma and death
What is the definition of concussion?
“a clinical syndrome due to mechanical, usually traumatic, forces characterized by immediate and transient impairment of neural function, such as alteration of consciousness, or disturbance of vision and equilibrium”
How long does a concussion usually last?
less than 6 hours
What is a cerebral contusion?
-bruise of cortical surface of brain from head trauma
What is a coup contusion?
type of cerebral contusion which occurs at point of impact
What is a contra-coup contusion?
type of cerebral contusion from backwards fall where abrasions prone to occur on contralateral side of brain opposite point of contact
What is the physiology of contusions?
- occipital bone hits againts cerebrum
- gelatinous cerebral tissue recoils and permits motion
- frontal and temporal poles hit against irregular, rough surface of ant. and middle cranial fossae at base of skull
How can contusions be classified morphologically?
minimal: limited to cortex and restricted to apex of gyri
larger: destroy large areas of cortex, expand into white matter; hemorrhage and edema create mass lesion with possible herniation and death
Are contusions permanent?
yes
How do contusions heal?
- bruised, necrotic tissue rapidly phagocytized by macrophages
- mild astrocytic proliferation forms local scar (gliosis)
- lesion finally ends up a pigmented crater
Where are contusions most prominent?
inferior and lateral aspects of cerebral hemispheres
What causes brain herniations?
- due to increased intracranial pressure
- cerebral edema, hydrocephalus
- focal tumors, abscesses, hemorrhages
What is the clinical presentation of brain herniations?
massive headache
vomiting
What is a subfalcine herniation?
cingulate gyrus herniation;
- asymmetrical expansion of cerebral hemisphere displaces cingulate gyrus under falx
- causes compression of brances of anterior cerebral artery
What is a tonsillar herniation?
- displacement of cerebellar tonsils through foramen magnum
- causes compresion of cardiac and respiratory centers
- leads to death
- called “Coning”
What is a transtentorial herniation?
- medial aspect of temporal lobe (hippocampus) is compressed against free margin of tentorium cerebelli
- causes compression of CN III with pupillary dilation and impairment of ocular mvmts on ipsilateral side
What is a duret hemorrhage?
- progression of transtentorial herniation often accompanied by irreversible necrotic and hemorrhagic lesions in midbrain and pons
- due to compression of vasculature
- linear or flamed-shaped lesions which usually occur in midline of brainstem
