Herniation Syndromes Flashcards
What happens in subfalcine shift
Essentially midline shift
What happens in tonsillar herniation
Cerebellar tonsils through foramen magnum
What are the four types of supratentorial herniation
Uncal, central transtentorial, cingulate (subfalcine) and transcalvarial
What are the two types of infratentorial herniation
Upwards cerebellar / transtentorial and downwards cerebellar / tonsillar
Where is an uncal herniation
Medial temporal lobe
What happens in a transcalvarial herniation
Brain moves out of cranium
What is the triad that is caused from herniation of cerebellar tonsils
Bradycardia, hypertension, low resp rate (Cushing’s)
What can happen to the eye in uncal herniation
Uncus can vrush the optic nerve where the sympathetics are affected, causing fixed dilated pupil
Treatment of herniation
Sit patient up, sedation, mannitol/hypertonic saline, decompression, reduced CSF
Why is the patient sat up/ head raised for management
Improves venous drainage and reduces ICP
How are patients sedated for management
By hypoventilating the patient
Why are patients ‘sedated’ for management
Low carbon dioxide leads to less volume of blood in the head (aim for 4.5kPa)
When do subfalcine shifts occur
Occurs early with unilateral SOPs
What happens in uncal herniation
Unilateral expanding mass causes the medial edge of the temporal lobe to push through tentorial hiatus.
What can happen after uncal herniation
As pressure increasees, central herniation can occur
