CSF Flashcards
ml/min?
0.3ml/min
absorption of CSF?
arachnoid villi (granulations)
Is the production of CSF pressure dependent?
no, only if so high, cerebral flow is reduced.
Is the resorption of CSF pressure dependent?
yes.
how much CSF does a newborn have?
5ml
how much CSF does a newborn produce per day?
25ml
What is normal Na and K in CSF?
Na: 138. K: 2.8
what is normal pH in CSF compared to plasma?
7.33 jmf 7.41
normal pO2 in CSF compared to arterial plasma?
43 compared to 104.
glucose level in CSF compared to plasma?
60 vs 90. obs higher in plasma.
total protein level in CSF compared to plasma?
35mg/dl c
vs 7000mg/dl.
Normal number of mononuklear or lymphocytes in CSF?
0-5 lymphocytes or monocytes.
normal no of polyleukocytes in CSF?
0
what is the best test for CSF?
Beta transferrin (Beta tracer)
What is the best bilddiagnostik to localize a fistula?
CT cisternography
How is a CT cisternography performed?
kolla upp!
When to suspect csf fistulae?
- rhinorrea after trauma
- otorrhea after trauma
- recurrent meningitis.
Kom ihåg rörande spontana CSF fistuale
- oftast äldre än 30 år.
- smygfiser, misstas ofta för rhinit.
! Pneumocephalus är OVANLIGT - titta efter infektion i paranasala sinus.
- kan vara associerat med empty sellae
- kan vara associerat med tumörer, inkl pituitary adenoma and meningioma.
!!!- persisterande rest av craniopharyngeala kanalen - Ibland associerat till ökat ICP o hcph.
- ibland associerat till agenesi av cribriform plate eller middle fossa.
- AVM association - jag vet ej hur.
- spännande! DEHISCENCE OF THE FOOTPLATE of stapes which can produce rhinorrea via the eustachian tube.
- dehischence belov foramen rotundum.
signs of spinal CSF fistulae
postural HA+neck stiffness+neck tenderness
Risk for CSF fistulae after trauma?
5-10%, increase if leak persist more than 7 days.
what is the most common pathogen in spinal CSF fistulae infections?
pneumococc 83%
Age differences in CSF fistulae infection
Better prognosis, (less than 10-50% mortality) than for pneumococcal meningitis w/o fistulae. Probably because these patients are younger.
BUT worse progrnosis in children.
What taste has CSF rhinorrea?
SALTY p 400
What special patient groups might have B transferrin w/o CSF leak?
newborns and liver diseased.
what other source than CSF produce betatransferrin?
vitrous fluid of the eye
How often is pneumocephalus presented on CT scan after CSF leak?
20%
How is a cisternogram performed to find a CSF leak?
- intrathecal injection of radionucleotide.
- scintigram OR
- injection of radiopaque and then CT scan
How many % of pt w CSF leak have anosmia?
5%
what is a pseudo-CSF rhinorrhea?
nasal hypersecretion from imbalanced autonomic regulation after skull base surgery. Ipsilateral to the surgery site.
What structure is most often involved in pseudo-rhinorrea?
the greater superficial petrosal nerve injuries. Due to imbalancing autonomic regulation.
What autonomic disturbances often accompanies pseudo-rhinorrea?
- loss of lacrimation ipsilaterally.
- facial flushing
- nasal “stuffiness”
How often is a water soluble contrast CT cisternography needed to localize a CSF fistulae?
10%
What to ask and look for in a CT to detect SCF leak?
- ask for thin CORONAL cuts through anterior fossa and back to sella turcica. W/WO contrast
- Look for:
Pneumocephalus
Fractures
Skull base defects
Hcph
Obstructive neoplasms
Contrast - abnormal enhancement of adjacent brain parenchyma possibly due to inflammation.
What is the role of MRI in finding CSF leak
R/O p-fossa mass
Tumor
Empty sella
* T2W1 fast spin w fat suppression might be used to try and see CSF flow direction.
When is CT cisternography indicated to find CSF leakage site?
- No site id on coronal plane thin slice CT
- The patient is actively leaking (otherwise difficult to trace w CT cisternography)
- Multiple bony fragments found and which is causing trouble is unknown.
- A bony defect seen on plain CT does not have associated changes of abnormal enhancement of adjacent brain parenchyma.
What vaccine is indicated after posttraumatic suspected SCF leak or postoperative?
pneumococcal vaccine. ( age 2-65yo)
non-surgical rek. in CSF leak
- Lower ICP
- Bed rest - can be discussed.
- Avoid straining - stool pills! No blown nose
- Acetazolamide 4x/d. 250mg (reduce CSF production)
- Modest fluid restriction but cautious after transsphenoidal due to possible DI. (1500/d)
2nd step rek. CSF leak
- rule out obstructive hcph.
- LP to H/A or normal pressure.
OR - percutaneous lumbar continous drainage.
-Head elevation 10-15 degree.
-Chamber at shoulder.
-15-20cc 1/h.
Indication surgical treatment CSF leak
*persisting more than 2 weeks although non-surgical interventions.
*spontaneous leaks
* delayed onset following trauma/surgery
*leaks complicated by meningitis.
MNEMONICS for intracranial hypotension findings
SEEPS-
S- sagging brain
E- enhancement of pachymeninges
E- Engorged veins
P- pituitary hyperemia
S- subdural fluid
treatment of “spontaneous” intracranial hypotension
Blood patch. mejority do well.
Pathophysiology of spontaneous intracranial hypotension
USUALLY connected to spontaneous CSF leak.
sometimes only “too little CSF production”
How can spontanoeus CSF leaks occur?
*Spinal Diverticulae usually thoracic spine. sometimes cervicothoracic junction.
*Lumbosacral perineural cysts
*Degenerative disc disease
*osteophytes
*bony spurs.
Underlying causes to spontaneous CSF leaks associated to spontaneous intracranial hypotension?
suspected “weak meninges” possibly associated to connective tissue diseases such as Marfan and Ehler Danlos.
Is there any connection between spontaneous intracranial hypotension and cranial SCF leaks?
No. No connection has been found.
What is the reason for orthostatic H/A in intracranial hypotension?
Descent of the brain causing strain on pain sensitive structures intracranially.
Recommendation when meeting a patient w new sudden onset of orthostatic H/A?
Brain MRI with contrast - SEEPS? Suspicion of intracranial hypotension.
what is the subdural fluid collection in spontaneous intracranial hypotension?
its seen in 50% of cases. 2X more often hygroma vs blood. only occasionally need intervention.
what is the subdural fluid collection in spontaneous intracranial hypotension?
its seen in 50% of cases. 2X more often hygroma vs blood. only occasionally need intervention.
Causes of blindness from hcph
- occlusioon of PCA by downward herniation
- chronic papilloedema causing injury to optic nerve and optic disc.
- dilatation of 3rd ventricle and compression of optic chiasm
What does DESH stand for?
disproportionately enlarged subarachnoid space hydrochephalus
What defines DESH on MRI?
*Enlarged Subarachnoid spaces in the Sylvian fissure and basal cistern and
*lessening of the subarachnoidal space over the convexity.
Callosal angle in NPH - what are the angles and why does it occur?
mindre eller = 90 grader.
On coronal MRI perpendicular to AC-PC line, passing through the posterior comissure.
- due to upward bowing and thinning
where is CSF produced?
- choroid plexus
- ependymal lining of ventricles
- dural sleeves of spinal nerve roots.
What three types of slit ventricle syndrome are there?
- Intermittent shunt occlusion
- Total malfunction
- Venous hypertension with normal shunt function
(De flesta med slit ventricles på CT har inget slit ventricle syndrome)
What happens with time in intermittent shunt occlusion slit ventricle syndrome?
the ventricles develop low compliance and a minimal dilatation result in high pressure and symtoms.
Jag tycker att detta verkar konstigt rent fysiskt.
total shunt malfunction in slit ventricles
When the ventricles cannot expand at all, either due to subependymal gliosis or due to Laplace law
Describe laplace law
It says that it takes higher pressure to expand a smaller container as opposed to a larger.
What is a slit ventricle syndrome with venous hypertension w normal shunt function?
p 441 - “It may occur in certain conditions like Crouzons, from partial venous occlusions. Usually subsides by adulthood
Explain slit ventricle syndrome with venous hypertension w normal shunt function?
KOlla upp detta vid tid
