Cerebrospinal fluid, intracranial pressure W1 Flashcards
where is CSF found?
ventricles of CNS and subarachnoid space
how many ml of CSF in total (approx) and how much is made every day?
125ml in total
500ml made per day
pathway of CSF flow?
lateral ventricles -> interventricular foramina -> 3rd ventricle -> cerebral aqueduct -> 4th ventricle -> lateral apertures and median aperture -> subarachnoid space -> reabsorbed at arachnoid villi
where is CSF produced
mainly choroid plexus of each lateral ventricle, partly choroid plexus of 3rd and 4th ventricles
functions of CSF
buoyancy
protection from physical injury
maintenance of brain perfusion
homeostasis
clearing waste
Monro-Kellie Doctrine thingy?
3 non compressible components in skull - brain, blood, CSF
increase in vol of one component requires a reduction in one or both others to maintain same ICP
normal pressure range of CSF
10-20cm H2O lying on side
20-30cm H2O sitting up
composition of CSF? (clinical features)
RBC = 0
WBC < 5/ μl (microlitre)
protein 0.1-0.45g/l
glucose >50% blood level
special tests of CSF?
gram stain and culture
oxyhaemoglobin & bilirubin
oligoclonal bands
increased white cell count in CSF?
infection - meningitis, inflammation of brain, spinal cord, etc - protein also raised
what does breakdown products of blood in CSF indicate?
bleed in brain
what are oligoclonal bands? what is this important for?
proteins called immunoglobulins. presence indicates inflammation of the CNS. may point to diagnosis of MS
2 types of problems with intracranial pressure
high or low pressure
high pressure ICP features?
headache worse when lying down, coughing, sneezing, stooping, straining
visual obscuration’s - grey/black out with ICP spikes
high pressure ICP - causes?
CSF overproduction
blocked CSF circulation
blocked CSF drainage
increase in blood or “brain tissue” within the skull
