CSF, Hydrocephalus, Lumbar Puncture Flashcards
What is Hydrocephalus?
condition whereby there is excess of CSF, pithing itracranial space, specifically, the intraventricular spaces within the brain- causing dilation of the ventricles and a wide range of symptoms.
where is CSF produced? Is it a passive or active process?
choroid plexus. active process that requires ATP where sodium pumped into subarachnoid space and water follows into the blood vessels
Where is the choroid plexus found?
lateral ventricles, post 3rd ventricle roof, and caudal 4th ventricle roof
is production equal to absorption in CSF?
yes
How much CSF do we produce, and how much is in our bodies and brain?
we produce between 450-600 ccs of CSF everyday.
What is the CSF pathway
- lateral ventricles (there are 2)
- Foramen of Monro
- 3rd ventricle
- cerebral Aqueduct (of sylvius)
- 4thventricle.
- Foramina of Luschka
- Foramen of Magendie
- then when leaves 4th ventricles hoes to subarachnoid space and around brain and spinal cord
- reabsorbed by arachnid granulations
How do arachnoid granulations absorb csf?
have arachnoid villi, which function as pressure-dependant one way valves that open when the ICP is 3-5cm greater than dural venous sings to pressure.
Is CSF absorption a passive or active process?
passive- needs no ATP.
driven by pressure gradient between the ICP and the venous system
2 types of hydrocephalus?
CommunicatingHydrocephalus (non-obstructive)
-Non communicating hydrocephalus (obstructive)
Difference between communicating and non communicating?
communicating-csf pathway is open from start to finish- no obstruction
-whilst non-communicative- obstruction
communicating hydrocephalus short name?
CoH
signs and symptoms of CoH in children?
In young children whose cranial sutures have not yet fused, you can see disproportional increase in head circumference compared to the rest of the face/body or failure to thrive
In children with fused sutures/adults, hydrocephalus manifests with symptoms of increased intracranial pressure;
other symptoms of CoH?
H/A, N/V. papilledmea, gait disturbance, 6th cranial nerve palsy, up gaze difficulty
aetiology of CoH?
Infection (incidence after bacterial meningitis can approach 30%)
Subarachnoid Hemorrhage (blood and blood breakdown products cause scarring of arachnoid granulations)
Post-operative
Head trauma
note form name of Non-communicating Hydrocephalus?
NCH
when is it NCH?
when there is ANY physical obstruction to the normal flow of CSF
NCH causes?
Aqueductal stenosis Tumors/Cancers/Masses Cysts Infection Hemorrhage/hematoma Congenital malformations/conditions
NCH symptoms rapid or gradual? and explain
if from process that develops over a longer period of time the symptoms will be gradual.
-but if its from an acute process like an intraventricular bleed- that can cause acute obstruction with rapid status decking
What radiography finding indicates hydrocephalus?
dilation of the temporal horns of the lateral vernticle
-in most younger and middle aged patients, these should be invisible.
- third ventricle will become ballooned
- lateral ventricle size increase
- peripheral sulk effaced
- evans ration-> 30%/ ventricular index>50%
Treatment for acute hydrocephalus?
reamins surgical
-acute hydrocephalus- whether communicating or not, needs urgent External ventricular Drain (EVD) passed through patients scalp and skull into lateral ventricle, that drains CSF to a collection system at patients bedside.
treatment for communicating hydrocephalus?
mainstay treatment is shunt placement.
if its an acute communicating hydrocephalus can be managed with evd and no shunt placements
treatment for non-communicating hydrocephalus?
surgical but sometimes shunt can be avoided by removing obstructing lesion
-can do third ventriculostomy
If a previously shunted patients presents with a headache does that mean it a shunt malfunction?
No, but it is a differential diagnosis
What condition can normal pressure hydrocephalus lead tp?
preventable/or reversible cause of dementia
