Cerebrospinal Fluid Flashcards
(27 cards)
CSF volume?
150mls in adults (500mls a day)
10-60mls in neonate
Function of the CSF?
Cushions the brain against mechanical forces
Contributes to maintaining intracranial pressure at a constant level
Transports metabolic waste products, antibodies, chemicals, and pathological products of disease away from the brain and spinal-cord tissue into the bloodstream
The CSF flows through which foramen to reach the subarachnoid space?
Magendi and Luschka
-Absrobed through the arachnoid villi into the venous drainiage system of the brain
What does raised protein in the CSF suggest?
Inflammation or infection
What should glucose level be in CSF?
Should be at least 2/3rds that of blood glucose
A ratio of BG less than 0.5 is pathological
Oligoclonal protein bands
Indicate inflammation in the CNS
How many RBC should be in the CNS?
0
How many WBC should you have in CSF?
<5WBC/ml
How much protein should be in CSF?
Less than 2g/dl
What level are the iliac crests?
L4
Which structures does the spinal needle pass through?
SSS I L EDS
Skin Superficial connective tissue Supraspinous ligament Interspinous ligament Ligamentum flavum Epidural spec Dura mater (dural sac) Subarachnoid space (lumbar cistern)
Indications for lumbar puncture
1) Suspected CNS infection
2) Suspected subarachnoid haemorrhage
3) Therapeutic reduction of CSF pressure
4) Sampling of CSF for any other reason
Contraindications to lumbar puncture
1) Local skin infections over proposed puncture site
2. Raised intracranial pressure (ICP)
3. Suspected spinal cord mass or intracranial mass lesion (based on lateralizing neurological findings or papilledema)
4. Uncontrolled bleeding diathesis
5. Spinal column deformities (may require fluoroscopic assistance)
6. Lack of patient cooperation (anaesthetic may be required in children)
CPP
Cerebral perfusion pressure
(the brain is metabolicaaly very active and requires a constant delivery of oxygen and glucose/energy to function normally)
How do you calculate CPP?
Mean arterial blood pressure - intracranial pressure
What will decrease CPP?
Decreased MABP
Raised intracranial pressure
Setting sun sign
Hydrocephalus
Prominent scalp signs may be a sign of what?
Hydrocephalus
Most important sign of hydrocephalus?
Enlarging head circumference
If you have hydrocephalus, what time of day would you get headaches?
Morning
-vomiting is more significant in the morning as well
Why might you get neck pain in hydrocephalus?
Tonsillar invasion
Which nerve is responsible for double vision?
Sixth nerve palsy
Signs and symptoms of hydrocephalus in the adult and older child?
Slowing of mental capacity, cognitive deterioration
Headaches (initially in the morning)
Neck pain, suggesting tonsillar herniation
Vomiting, more significant in the morning
Blurred vision: A consequence of papilledema and, later, of optic atrophy
Double vision: Related to unilateral or bilateral sixth nerve palsy
Difficulty in walking secondary to spasticity: Preferentially affects the lower limbs because the periventricular pyramidal tract is stretched by the hydrocephalus
Drowsiness
Investigations for hydrocephalus?
US, CT, MRI
