Hydrocephalus Flashcards
what colour is CFS normally?
clear
what is the function of CSF?
shock absorber
removal of some waste products
some immunological function
what conc of RBCs should be in CSF normally?
0
what is the normal volume of CSF?
150ml
where is CSF produced?
choroid plexus
where is CSF absorbed ?
arachnoid villi
what sinus is the CSF absorbed into ?
the superior sagittal sinus
what is the normal pressure of the CSF ?
0-20 cm
how does the CSF pass from the ventricles to the sub arachnoid space?
passes through lateral appendatures in the 4th ventricle
what two types of hydrocephalus are there?
obstructive
communicating
what cause obstructive hydrocephalus ?
when there is a blockage of outflow from the ventricles
what causes communicating hydrocephalus ?
Block at the level of the arachnoid granulations
- mismatch between production and absorption of the CSF
what are the signs and symptoms of hydrocephalus ?
raised ICP symptoms - vomiting - confusion - reduced GCS head ache (worse when coughing) can't look up visual disturbances
what investigation should be done for hydrocephalus ?
CT head scan
what investigation can be done for visual disturbances due to check raised ICP ?
fundoscopy
what should the CT scan look like for obstructive hydrocephalus ?
the lateral and 3rd ventricles would be enlarged but the 4th ventricle would be normal sized
what would suggest raised ICP on a CT scan?
not being able to see the gyri and sulci
is obstructive hydrocephalus a medical emergency ?
yes
two main categories of the cause of hydrocephalus is congenital and acquired
congenital =
chiari malformation
aqueduct stenosis
acquired = meningitis post haemorrhage neoplasm cerebellar stroke post traumatic
are babies or adults better at adapting to hydrocephalus ?
babies because their fontanelles haven’t fused yet so their head can increase in size
what medicine can be used to treat hydrocephalus ?
acetazolamide
how does acetazolamide work?
decreases production of CSF from the choroid plexus
what 4 surgical options for hydrocephalus are there?
EVD (external ventricular drain)
Eliminating obstruction
ETV (endoscopic third ventriculostomy)
CSF diversions
what is done during ETV (endoscopic third ventriculostomy)?
Hole is pierced in the inferior wall of the 3rd ventricle so CFS can flow from 3rd ventricle to subarachnoid space
what are the complications of inserting a shunt for CSF diversion ?
over/under drainage infection blockage disconnections seizures bowel can wrap around tube
what causes normal pressure hydrocephalus ?
- Brain is shrinking away form age and ventricles get larger
what is the main risk factor for normal pressure hydrocephalus ?
age
what is the classical triad of normal pressure hydrocephalus ?
dementia
gait disturbances
urinary incontinence
what is the treatment for normal pressure hydrocephalus ?
lumbar puncture
what is idiopathetic intracranial hypertension ?
partial obstruction to the absorption of CSF so pressures increases
when would a lumbar puncture not be done?
if the CT scan is normal and there is no obstruction causing hydrocephalus
when would a lumbar puncture be preformed ?
infection (meningitis) haemorrhage inflammation measuring the pressure of CSF communicating hydrocephalus
what are some risks of lumbar puncture ?
bleeding infection nerve root injury headache abdominal viscera injury brain stem herniation
