Patho Final Exam Concept Review Study Guide
Vegetative state verses brain death
•Vegetative state
➢Loss of awareness and intellectual function but continued brainstem function
▪Result of diffuse brain damage
▪Person unresponsive to external stimuli
▪If consciousness recovered may have significant neuro impairment.
•Locked-in syndrome
➢Individual is aware and capable of thinking but is paralyzed and cannot communicate due to
brain damage (may only be able to move their eyes to say yes or no)
•Criteria for brain death (declared clinically and legally dead)
➢Cessation of brain function
▪Including function of the cortex and the brainstem
▪Flat or inactive electroencephalogram (EEG)
➢Absence of brainstem reflexes or responses
➢Absence of spontaneous respirations when ventilator assistance is withdrawn
➢Establishment of the certainty of irreversible brain damage by confirmation of cause of the dysfunction
➢Evaluation twice by different physicians
Indicators of increased ICP
•Brain is encased in rigid, nonexpendable skull.
•Fluids, blood, and CSF are not compressible.
•Increase in fluid or additional mass causes increase in pressure in the brain
➢Ischemia and eventual infarction of brain tissue
•Increased ICP is common in many neurological problems.
➢Brain hemorrhage, trauma, cerebral edema, infection, tumors, abnormal circulation of CSF
•Early signs—if cause is not removed
➢Decreasing level of consciousness or decreased responsiveness (lethargy) 1st sign often
➢Severe headache
▪From stretching of dura and walls of large blood vessels
➢Vomiting
▪Often projectile, not associated with food intake
▪Result of pressure stimulating the emetic center in the medulla
➢Papilledema (visualize w ophthalmoscope)
▪Caused by increased ICP and swelling of the optic disc
•Vital signs
➢Development of cerebral ischemia
▪Vasomotor centers respond in attempt to increase arterial blood supply to brain
(causes vasoconstriction) *known as Cushing reflex
➢Systemic vasoconstriction
▪Increase of systemic blood pressure—more blood to brain to relieve ischemia
➢Baroreceptor response
▪In carotid arteries
▪Increased blood pressure by slowing heart rate
➢Chemoreceptor response
▪Respond to low carbon dioxide levels
▪Reduction of respiratory rate
➢Improved cerebral circulation
▪Relieves ischemia
