Hydrocephalus Flashcards
what is hydrocephalus
an excessive accumulation of CSF leading to the enlargement of the brain ventricles
mean csf pressure
10mmHg (>15 = abnormally high)
cfs produced per day
500mls
where is csf absorbed
arachnoid granulations
CSF four functions
Buoyancy (reduced brain weight by 96%)
Accommodates physiological changes in vascular volumes by displacing into spinal canal
Provides micronutrients
Homeostasis
2 types of hydrocephalus
Communicating + non-communicating
communicating hydrocephalus is due to …
impaired arachnoid granulations
3 possible cause of non-communicating hydrocephalus
tumour
colloid cyst obstructing 3rd ventricle
stenosis of aqueduct
How can you tell a non-communicating (obstructive) hydrocephalus on CT/MRI
4th ventricle is smaller than 3rd or laterals
Causes of congenital hydrocephalus
aqueductal stenosis chiari malformation (often type 1)
Clinical features of congenital hydrocephalus
dilated scalp veins (bulging or tense fontanelle)
Increased head circumference (thin and shiny scalp)
‘setting sun’ appearnace
Clinical features of acquired hydrocephalus
Headaches Vomiting Impaired upgaze (compression on tectal plate) raised ICP Papilloedema
Investigations for hydrocephalus
CT for acute diagnosis
MRI for assessing cause and location of obstruction
2 main surgical managements of hydrocephalus
VP shunt
ETV
Requirements for ETV to work
functioning CSF absorption pathways (non-communicating hydrocephalus) and a patent subarachnoid space.
