Flashcards in Cerebrospinal Fluid Deck (73)
Is the CSF-brain barrier and BBB the same thing?
What does the CSF-brain barrier relate to>?
The extracerebral fluid that is found within the ventricles and around the brain
What are the two main categories of function of the CSF-brain barrier?
What are the physical functions of the CSF-brain barrier?
- Cushions and protects the brain from shear forces and impact
- Plays a role in regulating intracerebral blood pressure, thus prevents ischaemia
What are the biochemical functions of the CSF-brain barrier?
- Removes waste and toxins from the CNS
- Helps regulate levels of hormones and neurologically active substances
What is CSF produced by?
A type of glial cell called an ependymal cell
Where is CSF produced?
Mainly in the choroid plexi in the lateral ventricles of the brain
Where does CSF exit after it's produced in the choroid plexus?
Through the intraventricular foramen of Munro, into the third ventricle
Where does CSF go after the third ventricle?
Through the aqueduct of Sylvius, into the fourth ventricle
Where does CSF go after the fourth ventricle?
Down the spinal cord and over the cerebral hemispheres
How is CSF reabsorbed into the circulation?
Via the arachnoid villi
At what rate is CSF produced?
What is the volume of CSF after age of 2 years?
What volume of CSF is found in the ventricular system after the age of 2?
What might abnormalities of CSF circulation result in?
What are the types of hydrocephalus?
What is the difference between communicating and non-communicating hydrocephalus?
In communicating, there is no obstruction between the ventricles and the subarachnoid space.
In non-communicating, there is a physical obstruction between the ventricles and subarachnoid space
What can communicating hydrocephalus be caused by?
- Excessive CSF production
- Impaired CSF reabsorption
Is excessive CSF production common?
No, it is rare
What can cause excessive CSF production?
Choroid plexus tumour
What can cause impaired CSF reabsorption?
Blockage of arachnoid granulations by debris after meningitis or haemorrhage
What can non-communicating hydrocephalus be caused by?
- Congenital malformations
- Acquired obstruction
Give 2 examples of congenital malformations causing non-communicating hydrocephalus?
- Aqueduct stenosis
- Arnold-Chiari malformations
Give an example of an acquired obstruction causing non-communicating hydrocephalus?
What is idiopathic intracranial hypertension?
A special case where the CSF is elevated in the absence of hydrocephalus or intracranial mass lesion
What does the treatment of hydrocephalus depend on?
What might the treatment of hydrocephalus include?
- Resection of intracranial obstruction
- Placing of stent in stenosed aqueduct
- Removal of excess CSF
How can excess CSF be removed in hydrocephalus?
Insertion of a one-way valved ventriculoperitoneal shunt
What does the insertion of a ventriculoperitoneal shunt form?
A direct drainage route for CSF from the cranial vault to the low pressure of the peritoneal cavity