Patho Lab 1 Flashcards
Basal ganglia hemorrhage
1) Putamen in particular
2) Non-traumatic and caused by hypertension that leads to arteriosclerosis (Damages and weakens small penetrating artery)
3) Blood collection -> Midline shift -> Secondary edema -> Herniation
Germinal matrix hemorrhage?
1) Intraventricular hemorrhage (Complication of prematurity
2) Arise in subependymal region (Germinal matrix very susceptible)
3) 28 weeks gestational age newborn
Basal ganglia hemorrhage may cause?
Stroke
Epidural hematoma
1) Results in blood clot on external surface of dura
2) Trauma -> Rupture of middle meningeal artery
What causes subdural hematoma?
1) Trauma with tearing of bridging veins
2) Particularly with cerebral atrophy (exposes bridging veins)
Bilateral chronic subdural hematoma
1) Blood clots are brown to tan because of organisation
2) Form more slowly and insidiously than clots from arterial hemorrhage
3) Most common in trauma in the very young and elderly
Berry aneurysm
1) Cerebral arterial circulation
2) Most common region is btw ant. communicating and ant. cerebral
3) Trifurcation of middle cerebral & bifurcation of int. carotid with post. communicating
4) Vertebral-basilar aneurysm <10%
5) Multiple aneurysms 20-30% cases
Ruptured berry aneurysm may cause?
Subarachnoid hemorrhage
Leakage of blood from aneurysm causes?
Ruptured aneurysm?
Headache -> Severe headache
Multiple aneurysms
1) Congenital
2) Defect presents from birth but take years to form so ruptured aneurysms usually occur in young and middle aged
Subarachnoid hemorrhage from ruptured aneurysm causes?
1) Vasospasm -> Cerebral anoxia
2) Sudden onset of excruciating headache
3) Mortality rate initial rupture 25-50%
Diffuse subarachnoid hemorrhage
1) Extend from base of the brain to lateral surface of frontal & temporal
2) No blood beneath dura
Lacunar infarcts in basal ganglia, deep white matter, brain stem (pons) caused by?
Arteriolar sclerosis caused by chronic hypertension
Arterial thrombosis and embolism may cause?
Acute cerebral infarct
Acute watershed infarction
1) Bilaterally symmetric dark discoloured area
2) Relative or absolute hypoperfusion of the brain
Remote watershed infarction
1) Subacute
2) Not bilateral
Thrombosis in internal carotid artery
Arterial thrombosis is far more common than venous (100:1)
Thromboembolus of cerebral artery
1) Particularly in middle cerebral artery and its distribution
2) Heart is the common source (Mural thrombus in the left atrium)
Subacute infarct
1) Liquefactive necrosis with formation of cystic spaces
2) Intermediate infarct
Hemorrhagic infarction
1) Caused by arterial embolus
2) Acutely edematous infarcted tissue may produce mass effect
3) Decrease size of lateral ventricle
4) Midline shifted to contralateral side of lesion
Acute infarction with anoxic injury
1) Red neurons (Hypoxia)
2) Hippocampus and purkinje cells (Red cytoplasm, indistinct cytoplasmic borders, karyolysis) are highly susceptible
Subacute (intermediate) infarct
1) Edema with obscured structural lining
2) Swelling that shifts midline to the side
3) Liquefactive necrosis with formation of cystic spaces
How cystic spaces are formed?
Resolution of liquefactive necrosis (remote infarct) by influx of blood monocytes to become tissue macrophages over weeks leads to cystic spaces formation
Remote cerebral infarction causes?
1) Wallerian degeneration (decreased descending corticospinal tracts)
2) Cerebral peduncle of midbrain is reduced unilaterally
Cerebral edema
1) Shift of midline to the side
2) Multiple metastases may be the cause
3) Widened gyri with flattened surface and narrowed sulci
Herniation of uncus of the hippocampus through tentorium and herniation of cerebellar tonsils through foramen magnum caused by?
Acute brain swelling
Duret hemorrhages (Pons)
1) End result of herniation
E.g. Uncal herniation from edema
Pseudolaminar necrosis
1) Persistent vegetative state
2) Cortical ribbon is very thin (loss of cortex)
