Neurological Pathophysiology. Edema in the CNS. Increase in tissue mass that results from the excess movement of body fluid from the vascular compartment or its abnormal retention in the tissue. Why is this a special problem in the brain and spinal cord? Enclosed space Lack of lymphatics
Since the brain is encased in the cranium, the only way pressure can be relieved is by decreasing cranial contents.
When ICP begins to = arterial pressure, there is a lack of compensation- beginning decompensation Stage 3
closed (blunt) trauma
open (penetrating) trauma
Break in dura results in exposure of brain tissues to environment.
Results in focal (localized) injury
May be due to skull fracture or wound – intracerebral hematoma
Traumatic pneumocephalus - injury to a nasal sinus that allows air into brain or ventricles - cerebrospinal rhinorrhea
More common than open trauma.
Involves head hitting hard surface or rapidly moving object strikes head
Dura is intact – no brain tissue exposed
May cause focal or diffuse axonal injury (DAI)
Contusions (bruise) : impacts which lead to hemorrhage and possibly hematoma
Coup (strike) – head strikes against object
shearing forces cause small tears in blood vessels (subdural vessels)
severity = force
smaller area = greater force
and damage opposite to site of impact
Ischemia (with or without infarct)
petit mal – almost imperceptible alterations in consciousness
grand mal – generalized tonic-clonic seizures – dramatic loss of consciousness, falling, generalized tonic-clonic convulsions of all extremities, incontinence, and amnesia for the event.
Epileptic cry – respiration stops