Raised ICP, SOLs & Trauma Flashcards
1
Q
What is the sequence of events leading up to the RAPID rise in ICP?
A
- enlargement of brain> some BLOOD/CSF escaping from cranial vault
- process is exhausted, venous SINUSES flattened, little/no csf
- further incr. in brain volume> RAPID ICP incr.
2
Q
Causes of raised ICP?
A
- incr. CSF (HYDROCEPHALUS)
- SOL (focal brain lesion)
- diffuse brain lesion (edema)
- incr, VENOUS volume
- physiological (HYPOXIA/HYPERCAPNI/ PAIN)
3
Q
Define hydrocephalus.
A
- accumulation of excessive CSF in the VENTRICULAR system
4
Q
Normal CSF volume.
A
- 120-150ml
5
Q
How much CSF produced in a day?
A
500ml
(3-5 times/day
6
Q
Where is CSF produced?
A
- choroid plexus in the LATERAL and 4th ventricles of the brain
7
Q
Where is CSF absorbed?
A
- by arachnoid granulations
8
Q
Normal parameters of CSF?
A
- Lymphocytes <4cells/ml
- neutrophils: 0
- proteins <0.4g/L
- glucose >2.2mmol/l
- no RBCs
9
Q
What may cause Hydrocephalus?
A
- csf flow obstruction
(by pus/tumors/inflammation) - decr. RESORPTION of CSF (post SAH/ meningitis)
- overprodn of CSF (v. rare/ tumors of choroid plexus)
10
Q
Why may SAH later cause hydrocephalus?
A
- d.t consequent arachnoiditis
11
Q
What anatomical pathology may be present in the 3rd ventricle to cause hydrocephalus?
A
- CHIASMAL gliomas
- craniopharyngiomas
- arachnoid cysts
12
Q
Pathology at the 4th ventricle to result in hyrdocephalus?
A
- medulloblastomas
- ependyomas
- astrocytomas`
- dandy-walker cysts
13
Q
What is meant by a non-communicating hydrocephalus?
A
- obstr. to flow of CSF WITHIN the ventricular system
14
Q
if communicating hydropcephalus….what could be the cause?
A
- something obstructing the follow of csf OUTSIDE the VS.
- —-in subarachnoid space/ at arachnoid granulations
15
Q
When is cranial enlargement seen?
A
- IN bbies
- when hydrocephalus occurs BEFORE the closure of cranial sutures
