Notice that the lateral and third ventricles are enlarged, but the fourth is not.
What are they signs and symptoms of normal pressure hydrocephalus?
Is this communicating or non-communicating hydrocephalus?
Triad of sx:
- Ataxic gait
- Urinary incontinence
Intermittent increase in CSF pressure, but not constant.
Imaging will show communicating hydrocephalus.
What are the 4 functions of CSF?
The functions of CSF are as follows:
- Shock absorber
- Moves metabolites away from the brain due to one-way flow.
- CSF moves hormones around in the brain.
Chiari II, notice how the cerebellum is protruding through the foramen magnum.
What are the causes of aqueductal stenosis?
Tumor pressing on the aqueduct
Congenitally narrow aqueduct
What are the ventricles and foramen, in order of the flow of CSF?
Lateral ventricle -> Foramen of Monro -> Third Ventricle -> Cerebral aqueduct -> Fourth ventricle -> Lateral foramina of Luschka and Medial foramina of Magendie -> Subarachnoid space
(CSF also goes from the fourth ventricle into the central canal of the spinal cord)
What are the typical findings in a Dandy-Walker malformation?
Cystic enlargement of the fourth ventricle.
Missing or underdeveloped vermis of the cerebellum.
Swelling of the base of the skull in infants.
What are the components of the blood–CSF barrier, and how does it differ from the blood brain barrier?
The blood-CSF barrier is more permeable than the blood brain barrier, and is made up of the tight junctions between the choroid cells, as well as the basement membrane. There are endothelial cells of course, as in the blood brain barrier, but in the BBB these endothelial cells have tight junctions, and in the blood CSF barrier the endothelial cells are fenestrated.
What causes hydrocephalus ex-vacuo?
Is this obstructive or non-obstructive hydrocephalus?
Brain atrophy (schizophrenia, dementia, head trauma) causes CSF to expand into those spaces. (CSF pressure is normal).
What are the expected findings in Chiari II malformation?
Herniation of the medulla, cerebellum, and fourth ventricle through the foramen magnum.
What are the signs and symptoms of aqueductal stenosis?
Upward gaze palsy
Enlarged head in infants
Cognitive or developmental delay
Notice the large cystic expansion of the fourth ventricle.
Also notice that this is a T2 MRI, which they did not show us. Don't be confused if they use T2s on the test.