TYPES OF BRAIN BLEEDS
Brain bleeds (Intracranial Hemorrhages, ICH) can be classified based on the brain compartment involved and the cause:
1- Bleeding into brain tissue (Hemorrhagic stroke, Intracerebral hemorrhage, Intraparenchymal hemorrhage, IPH): the most common type, mostly due to small vessel diseases of the brain in older adults but many less common causes exist. Most common small vessel disease related hemorrhages are:
Cerebral Amyloid Angiopathy (CAA)
2- Primary Intraventricular Hemorrhage: bleeding inside the ventricles, i.e. spinal fluid containing spaces in the brain
3- Bleeding inside the coverings of the brain
Subarachnoid hemorrhage (SAH) -> 85% related to aneurysms (balooning) of brain arteries
Subdural hemorrhage (SDH) -> either related to trauma OR "chronic, spontaneous" in older adults
Epidural hemorrhage (EDH) -> mostly related to trauma, rare but very severe type
4- Smaller hemorrhagic pathologies visible especially on brain MRI
Microbleeds -> very small amount of "oozing" from the small vessels of the brain, visible on special MRI sequences (SWI or GRE)
Superficial siderosis -> small layer of very superficial bleeding, visible on MRI, mostly seen in CAA
5- Other, non-bleeding pathologies that might signal a higher risk of brain bleeding
White matter disease -> probably related to inadequate flow to deeper brain regions, related to the small vessel diseases that also cause bleeding (CAA, hypertensive)
Lacunar infarcts -> small deep infarcts that commonly cause stroke symptoms (3-15mm diameter)