8. Ventricle CSF and Hydrocephalus Flashcards
At one time, there are about 125-150mL of CSF in the body, constantly renewed. Where can most of the CSF be found?
65% is found in the lateral ventricle
Choroid plexus produces the CSF which is a specialized layer of ependymal cells which makes what?
choroidal epithelium overlying highly vascularized villi
In the BBB, there are continuous tight junctions between the ENDOTHELIAL cells, a basement membrane, astrocytic foot processes. What is different in CSF blood barrier? 3
separating the CSF from blood
more permable than BBB
tight junctions are located between CHOROID cells
Normal CSF is clear and colorless with few cells and low protein, offering quantitative differences from plasma. What is the most important difference between CSF and plasma?
protein in plasma is 7000 will it is 20 in CSF
increase or decrease in proteins in CSF = pathology
What are the four main functions of CSF?
protection: shock absorber
buoyancy
Metabolic - takes drugs away from brain
Endocrine medium: hormone transport
What are the four cavities within the brain?
lateral ventricle 3rd ventricle cerebral aqueduct 4th ventricle (continuous with with central canal in SC)
How does the CSF leave the fourth ventricle? (2)
2 lateral foramina of luschka
1 medial foramen of magendie
What is the entire pathway for CSF flow? (9)
CSF is made from choroid plexus from blood-csf barrier
- Lateral ventricle
- interventricular foramen of monroe
- third ventricle
- cerebral aqueduct
- fourth ventricle
- lateral and median apertures (lateral foramina of luschka/ medial foramen of magendie)
- Subarachnoid space
- Arachnoid Villi of dural venous sinuses
- Venous blood
What is the difference between arachnoid villi and granulations?
granulations are older while villi are new
What is expansion of the ventricular system due to increase volume of CSF contained within them?
hydrocephalus
The causes of hydrocephalus can be due to overproduction, under absorption at villi, or obstruction of outflow from ventricles. What are they two types?
communicating/ non-obstructive
non-communicating/ obstructive hydrocephalus
What type of hydrocephalus is due to a blockage after the ventricles due to abnormalities of arachnoid villi, associated with increased ICP?
communicating/nonobstructive hydrocephalus
What hydrocephalus is characterized by enlarged lateral and 3rd ventricles and increased CSF pressure?
Normal Pressure Hydrocephalus
What are the traid of symptoms associated with normal pressure hydrocephalus?
dementia
apraxic gait
urinary incontinence
What is a compensatory enlargement of cerebral ventricles and subarachnoid spaces, typically with no increase in CSF pressure?
Hydrocephalus Ex-Vacuo
What are the 3 common causes of hydrocephalus Ex-Vacuo?
brain atrophy
post-traumatic brain injuries
Psych disorders like schizophrenia
What is caused by CSF flow obstruction that occurs within the ventricular system, with the enlargement being located proximal to the obstruction?
obstructive hydrocephalus
What is narrowing of the cerebral aqueduct blocking the flow of CSF (MOST COMMON SITE), caused by tumors, narrow aqueduct, and gliosis?
Aqueductal stenosis
What are the most common signs and symptoms of aqueductal stenosis? 6
thunderclap headache (severe/sudden onset) papilledema enlarged head cognitive delays decreased consciousness cant look upwards
What is the disease associated with a large posterior fossa cyst continuous with the fourth ventricle, involving hypoplasia of cerebellum and agenesis of cerebellar vermis?
dandy-walker malformation
What is caused by herniation of the cerebellar tonsils and medulla through the foramen magnum, usually accompanied with myelomeningocele and hydrocephalus?
Chiari II Malformation
What develops later in life and occurs when something happens to prevent CSF in the brain from draining properly? (5)
Acquired Hydrocephalus Tumor Block CSF flow Bleeding (subarachnoid hemorrhage) Head trauma Infection/meningitis
