WEEK 2: PATHOLOGY PART 2 [ERF] NOT INCLUDED YET Flashcards
3 types of intracranial hemorrhage
epidural
subdural
subarachnoid
Bleeding between the inner table of skull and dura
epidural hemorrhage
typical cause of epidural hemorrhage
trauma; Due to structural disruption of the dural and skull vessels
commonly associated with calvarial fractures
most common etiology of epidural hemorrhage?
Laceration of the middle meningeal artery and its
accompanying dural venous sinuses
when does symptoms appear in epidural hemorrhage?
Blood volume reaches 30-50 cc symptoms appear
can epidural hemorrhage become asymptomatic?
first 4 to 8 hours
cause of subdural hemorrhage?
Trauma to the frontal or occipital regions of the head
Rapid displacement of the cerebral hemispheres against the
inner aspect of the skull
Shearing effect on the bridging veins within the subdural
space
Subdural: Shearing of the Beins
Commonly blood accumulating to a volume of 25-50 cc
results in a tamponade effect on the ruptured bridging veins
what hemorrhage is most common in shaken baby syndrome?
subdural hemorrhage
most often caused by head injury rapidly changing velocities within the skull may stretch and tear small veins?
subdural hemorrhage
most common cause of subarachnoid hemorrhage?
berry (saccular) aneurysm, commonly in the circle of willis.
most common d/t Due to congenital defects of the smooth muscle fibers of
the tunica media
MC location of congenital saccular aneurysm in the brain.
branch of the middle cerebral/portion of ICA just before maging MCA siya
but it can occur in any part of the circle of willis
Interruption of blood supply commonly due to blockage or rupture
of blood vessel causing sudden death of brain cells
CVA
why is MCA one of the most common location of CVA
because it does not form the circle of willis
MC of intracerebral hemorrhage?
hypertensive vascular disesase.
cause of ischemic stroke?
Caused by thrombotic or embolic occlusion of a cerebral
artery
ischemic infarction may lead to what 2 consequences?
cerebral edema; inc ICP
most common congenital anomaly that can cause stroke?
arteriovenous malformation
where are AVM usually located?
superficial portion of gray matter
CNS tumors are how many percent of all tumors?
10%
most common solid cancer in children?
CNS Tumor; 2nd siya to leukemia if all malignancies
peak of age of CNS tumor?
double peak; 1st and 6th decade
location of CNS tumor in adult and children?
adults- 70% supratentorial
children- 70% infratentorial
classifications of intracranial tumors?
metastatic (majority)
extrinsic
intrinsic
most common extrinsic tumors of brain?
meningioma
distribution of metastasis in the brain is most common in what area?
cerebral hemishpere - 80 percent
cerebellum - 15
brain stem - 5 percent
Many cancer cells that enter the brain are killed by
astrocytes by secreting a protein called
Fas Ligand
Is charcot-bouchard microaneurysm a congenital problem?
no. acquired because of continuous trauma and degeneration of
the tunica media, wherein the smooth muscle layer is
replaced with fibrous tissue.
why is the bifurcation of ICA and MCA the most common site of aneurysm?
The bifurcations produce Eddy currents which causes trauma to the endothelial cells. This in turn causes the entry of triglycerides, setting into motion the development of atherosclerosis.
A lot of cerebral infarcts, later on, are associated with
hemorrhage. why?
Because when a vessel undergoes infarction, the surrounding blood vessels also die. So then how will the hemorrhage occur? Remember that the unobstructed portion of the other branches are still patent, therefore blood will still drain into the infarcted part of the brain and will cause some degree of hemorrhage
Brain tumors have rare extraneural spread. tor f?
T
most common causes of brain metastasis in adults?
Lung 50 percent
Breast 15 to 20 percent
4 implications (risk factor) on the pathophysiology of brain tumors?
pathogenesis is mostly unknown. but the following have been implicated.
Genetic factors
chemical and viral factors
Radiation
Immunosuppression
most common tumor in children in cerebellum?
medulloblastoma most common in children in the cerebellum
T or F? Behavior of CNS tumors cannot be readily categorized into benign or malignant
T
Arise from the coverings of the brain and spinal cord
extrinsic brain tumors
most common extrinsic brain tumor?
meningioma, more common in females
WHO classification of meningioma: what is
grade 1
grade 2
grade 3
benign (90%)
atypical (7%)
anaplastic/malignant (2%)
most common histologic subtype of meningioma?
meningothelial
most aggressive histologiuc subtyppe of meningioma?
angioblastic
what hormones are risk factors in having meningiomas?
estrogen and progesterone
most common site of schwannoma
vestibular branch of the 8th cranial nerve in the region of the cerebello-pontine angle, aka acoustic neuroma.
usually arise in the dorsal nerve roots of the spinal cord; most frequently in patients with neurofibromatosis.
neurofibroma
infiltrate any portion of the brain; most common type of brain tumor.
Gliomas
most common brain tumor, accouning for more than half of all primary CNS malignancies; Most cases occur in the first decade of life -> Peak age at 5-9 years.
astrocytoma
Astrocytomas come in four major subtypes:
Juvenile pilocytic astrocytome (grade 1)
o Fibrillary/diffuse astrocytoma (grade 2)
o Anaplastic astrocytoma (grade 3)
o Glioblastoma multiforme (grade 4)
type of astrocytoma that has is highly aggressive with short life expectancy
glioblastoma multiforme
most common malignant brain tumor in children, accounting for 10-20% of primary CNS neoplasms and approximately 40% of all posterior fossa tumors– > Highly invasive embryonal neuroepithelial tumor.
medulloblastoma
Cerebellar tumor arising predominantly from the _______
cerebllar vermis.
Most common neuroblastic tumor in the CNS
Almost exclusively in the cerebellum arising from the external granular layer of cerebellum.
medulloblastoma
you can have a Primary CNS Lymphoma without having Lymphoma elsewhere. T or F
T
intrinsic brain tumor most common in adults; usually located in white matter of cerebral hemisphere.
Oligodendroglioma
epednymoma is often located in?
4th ventricle
intrinsic brain tumor located in the suprasellar region causing pituitary dysfunction and visual disturbance
craniopharyngioma
choroid plexus papiloma is common in what ventricle?
lateral ventricles
