Epidural Hematoma, Subdural hematoma, Subarachnoid hematoma, Intracerebral hemorrhage

MISTAKE @5:06: CN3 Palsy causes pupil dilation, not constriction!
In this video we will be covering of Cerebral Hemorrhages such as epidural hemorrhage, subdural hemorrhage, subarachnoid hemorrhage, and intracerebral hemorrhage in preparation for USMLE Step 1. We will be covering the neuroanatomy and pathophysiology, diagnosis of these conditions for the purposes of USMLE Step 1
ANATOMY
The meninges is made up of the skull, dura mater which is made up of periosteal and meningeal layer. Then the arachnoid mater and pia mater. In between these two there is cerebrospinal fluid (CSF) known as the subarachnoid space
EPIDURAL HEMATOMA or EPIDURAL HEMORRHAGE
Caused by rupture of the middle meningeal artery in between the two layers of the duramater. When this ruptures it seperates the two layers of the dura mater. The middle meningeal artery comes from the foramen spinosum and moves laterally where it then splits anteriorly and posteriorly. Therefore trauma to the lateral side of the head there can be rupture of the middle meningeal artery and blood will flow between the two duramater layers. Therefore epidural hemorrhage is caused by trauma to the lateral part of the head causing rupture of middle meningeal artery. Symptoms are interesting. They will be unconcious for awhile due to trauma. Then there is a lucid interval where they are okay for a few hours and then they will go into coma. Also there is Cranial Nerve three palsy. On CT findings there is something called the lens shapred on the side of the head. This lens shape is created by the presence of fissures that it can't pass. However, it can pass the falx cereberi and tentorium cereberi.
SUBDURAL HEMATOMA or SUBDURAL HEMORRHAGE
Here the hematoma is immediately under the duramater. Briding vessels also known as superior cerebral vessels rupture. These veins are between the cerebrum and the skull. When there is shaking of the brain severe enough it will lead to rupture of the vein and blood will flow. Brain atrophy caused by old age and alcohol can predispose to Subdural hematoma or subdural hemorrhage. Symptoms are delayed because of the slow bleeding. Also there is some history of trauma such as fall, epilepsy or motor vehicle accident. Investigations you would want to perform is the CT Scan. On CT Scan subdural hematoma will show in a more elliptical pattern. This crosses the fissures, but does not cross the falx or tentorium cereberi.
SUBARACHNOID HEMATOMA or SUBARACHNOID HEMORRHAGE
Here there is hemorrhage into the subarachnoid space. Here there is CSF and the LP will show blood. Subarachnoid hematoma is caused by berry aneurysm around the circle of willis. This is caused by Ehlor Danlos/Marfan's, ADPKD, and finally subarachnoid hematoma is caused by AV malformation. Symptoms are classically described as "worst headache ever". Very sudden onset and there is no history of trauma. Often times there is vasospasm which is not seen by CT scan and the treatment is the nimedipine which is a calcium channel blocker.
INTRACEREBRAL HEMORRHAGE
This hemorrhage is within the brain, not in the meninges. Caused primarily by system hypertension that leads to microaneurysm in the the lenticular straite aslso known as Charcot Couchard. Also found in the Basal Ganglia. There are some condition associated with this condition. Amyloid angiopahty, vasculitis and neoplasms.

[@mayank9822]

middle meningeal artery is between the periosteal dura mater and skull and not between periosteal and meningeal dura mater.

[@RN-allpatientcare]

Thank you for this video. I’m preparing for my neuro exam. From my studies and research, I think the epidural bleeding is specifically between the calvaria and the periosteal dura (outer membrane of dura). Not between the 2 layers of dura which would mean that it is between the periosteal layer and meningeal layers of the dura. Your video is very easy to understand though. Thank you so much for the effort you put into this.

[@zeinabghamlouch9920]

thank you so much, explained everything very quickly, straight to the point and very informative, all i needed, thanks a lot !

[@fredababe]

CN III - Down and out, Pupil Dilatation!!!

[@nelsonlouis5491]

Very clear explanation on intracranial haemorrhage. Thank u so much!!!

[@sunshineshrty]

simple and to the point

[@mikeymindset]

Isn't the middle meningeal artery between the periosteal dura mater and the skull, as opposed to the periosteal dura mater and the meningeal dura mater ?

[@rznotorious6103]

in most medical literature, its site is said to be btween the two dural layers

[@thilinaalagiyawanna3680]

Thank you very much

[@sarap7879]

this was so helpful! thank you so much

[@thestudyspot]

+Sara 01 Your Welcome! Glad you found it helpful!

[@nikolozibostashvili4625]

pupil dilation

[@user-bo5xx7fu2k]

Ture he was wrong

[@picfunmedicosis1187]

Great video

[@shariquekhan9328]

Thank you sir
From India

[@renmachard]

the study spot I have realized that even though the meningeal artery runs between the two layers of dura, they refer to it as "extra dural" My question to you then is where is the intradural space? I personally thought the intradural space would be between the two layers of dura but the more I read the more it feels as if the intradural space is actually the same as the sub dural space

[@niharnayak1614]

Nice

[@rals8899]

Thank you so much for your videos! They are helping me a lot in my preparation for the USMLE. I was curious to know what drawing program you used for your videos. i'd like to use something similar to take notes. Thanks again.

[@niharnayak6417]

Great lecture sir but isn’t occulomotor palsy associated with DILATED pupils?

[@ademiravdic]

correct

[@makk3435]

inner mennengeal layer of dura goes with falx which u have not shown????

[@user-dq4gl1vt9f]

thank you so much sir

[@avnigautam4508]

where was the bit about hematoma?

[@MsMusicObsessed]

Thank you :)

[@micadimare4821]

what does it mean ADPKD? tk u
but the way, the video is great

[@armaniwaise5287]

Mica Dimare autosomal dominant polycystic kidney disease

[@scottrezajafarian2502]

Autosomal Dominant Polycyctic Kidney Disease