Originally Posted by bimaindra26
What about the difference of sign and symptom between them?
They all have different vessels that are bleeding first of all and they all have different causes as to why they are ruptured.
Epidural - meningeal arteries (most common middle meningeal artery, runs on the inside of the temporal bone). Fracture to the temporal bone causes rupture of the artery. After the trauma the patient will lose consciousness, then regain it and appear to be doing better, however, once the bleeding becomes extensive (and it does so very quickly) the patient will deteriorate again due to transtentorial herniation. Since the dura is connected to the periosteum at the suture lines the bleeding will be contained within the suture lines. It will have a biconvex appearance on a CT. Also, the bleeding is arterial (high pressure).
Subdural - bridging veins which kind of go across the dura rupture between the dura and the arachnoid. The major risk factor here is the increased distance that the veins have to travel. If the subdural space is increased (due to brain atrophy for example) the veins have to go a longer distance making them more vulnurable. Any injury that can move the brain inside the skull can rupture those veins. Since the veins are firmly attached to both dura and the arachnoid when the brain moves the arachnoid moves with it, dura does not-> veins are stretched and ruptured. Larger the space, larger the risk of it rupturing. You have to imagine it, it is very hard to explain. Causes are multiple, few that come to mind are whiplash injury, shaken baby syndrome, elderly and alcoholics with brain atrophy. Children also have increased subdural space because their brains are not yet fully developed. The bleed is venous, slow. The onset of symptoms is also slow. Usually a headache. CT will show bleeding that crosse the suture lines.
Subarachnoid - rupture of cerebral aneurysms, classically at branching points (beacuse 1. turbulence and more importantly 2. underdeveloped tunica media at the branching points in the circle of Willis). Anything that increases the risk of aneurysms will increase the risk of subarachnoid hemorrhage, few that come to mind hypertension, Marfan, Ehlers-Danlos. Presents as an acute severe headache (buzz word: the worst headache of my life). There will be RBCs in the CSF (on lumbar puncture). Very dangerous, highly fatal. Need to be careful because there usually is a vasoconstrictive response few days after the hemorrhage and need to give nimodipine prophylaxis (a calcium channel blocker used exclusively for this cause).
Intraparenchymal - same thing as intracerebral. Bleeding occurs inside the bran tissue itself. Most commonly caused by hypertension. Classically due to the rupture of aneurysms (Charcot-Bouchard) of lenticulostriate vessels which feed the basal ganglia and some other structures. It will basically stroke out the are of the brain that was fed by the ruptured vessel and also displace and compress nearby brain tissue.