Hydrocephalus (NeuroAnatomy and Physiology of CSF) for USMLE
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- čas přidán 6. 09. 2024
- Discussing physiology and neuroanatomy of cerebrospinal fluid and pathophysiology of hydrocephalus for USMLE Step 1. Conditions covered are hydrocephalus, communicating hydrocephalus, noncommunicating hydrocephalus, hydrocephalus ex-vacuo and normal pressure hydrocephalus.
ANATOMY AND PHYSIOLOGY OF CSF FLUID
Begins with the lateral ventricles located above the thalamus. This continues as the third ventricle, cerebral aqueduct, fourth ventricle and then goes into spinal cord. The lateral ventircle is located in telencephalon. The third ventricle is in the diecephalon. The cerebral aqueduct is in the midbrain. The fourth ventricle which is found in mesecephalon.
Above the fourth ventricle is the corpus collosum and divided by the septum pellucidum. And below is the caudate nucleus. The cerebellum encompasses the pons and medulla.
The entire brain and spinal is surrounded by subarachnoid space. The dura mater is surround the arachnoid mater which, but there are certain areas where it creates sinus, such as superior saggital sinus. There are a few foramens such as the foramen of Monroe or interventricular foramen. The cerebral aqueduct and finally in the fourth ventricle you have the foramen of lushka and foramen of Magenda.
The cerebral spinal fluid is produced by the ependymal cells called the . The fluid goes through the lateral ventricle, then the third ventricle, then the cerebral aqueduct, the fourth ventricle. It goes through the foramen of lushka into the pontine cistern. Foramen of magenda goes into the cistern magna. From there it goes into the spinal cord and goes up towards to the cerebellar area. Here there are arachnoid granulation that go through the superior saggital sinus and goes to the venous blood.
HYDROCEPHALUS
Hydrocephalus is any condition that leads to increase CSF fluid.
Increase production is one cause however it is very rare. The only cause can be a tumor of the choroid plexus.
Circulation can be two types such as communication and non-communicating. Noncommunicating means that the problem is before the foramen of lushka and magenda. This can be found in a cyst in the foramen of Monroe which will block the flow and cause enlargement of the area. Cerebral aqueduct can be caused by congenital stenosis. And cerebellar tumors which compress the foramen of lushka and magenda.
Communicating causes means there is a problem in the subarachnoid space. Arachnoid stricture post meningitis is one common cause.
Decrease drainage is focusing on the arachnoid granulation which may become clogged and then the fluid can't drain into superior saggital sinus and can't go into the venous fluid.
Normal pressure hydrocephalus is when the brain accomodates the increase spinal fluid by compressing itself. Therefore there is increased CSF but no increase pressure. Leads to the 3W symptoms. Wacky, wobbly, wet. Dementia, gait, urinary incontinence are the three primary symptoms of normal pressure hydrocephalus.
HYDROCEPHALUS EX-VACUO
Atrophy causes increase CSF to take up the extra space. This hydrocephalus can be caused by alzheimer, huntington, and psuedotumor creberi
the mechanism for ataxia in NPH has nothing to do with the cerebellum. It is related to the frontal lobe abnormalities (frontal ataxia/gait apraxia) leading to specific magnetic gait.
Yes!
Best explanation i've seen so far! Been looking for a more thorough explanation and Im happy I found this!
Don't you have the pressure gradient in NPH backwards? The ventricles enlarge to accommodate the increased CSF, pushing outwards on the cerebrum, not inside.
Wow, thanks to this video I will never forget this topic. 👍🏼
Excellent presentation...
👏👏👏👏👏👏👏💗💗💗💗Wonderful!!!! Thank you sooo much
So helpful thank you 🙏🏻
very good and informative video..thank u
khaled elsaba Glad you found it beneficial!
Loved the video! Thank you :)
I have question I do have hydrocephalus and did already have 3 surgery of vp shunting and last one I have is back 2005 to present but recently I am experiencing head ache it starts at the back yesterday I had a ct scan and the impression is communicating hydrocephalus does that mean that my vp shunt is not function well again?
did u have any video about clinical feature of hydrocephalus?
Quite informative . Thank you. :)
Thank you for the video
You are amazing Thank you 🌹
Big thanks 😍
Thank u very much :-)
Thanks a tonn doctor
Thank you sir
tank's *****