-
Integrity of blood brain barrier is disrupted
causing interstitial edema
Vasogenic edema
-
increase in intracellular fluid from
hypoxic-ischemic insult
Cytotoxic edema
-
medial aspect of the temporal lobe compressed
against the tentorum, third nerve compressed resulting in pupillary dilation on
the side of the lesion
Transtentorial(uncal hernitation):
-
unilateral expansion of cerebral hemisphere displaces the cingulate gyrus under the falx cerebri
Cingulate gyrus herniation
-
Cerebellar tonsil displaces through the foramen magnum, brain stem compression of respiratory centers
- Tonsillar herniation
- Most life threatening
- Prevent by medicine, holes in skulls
-
Midline and pons, due to brain herniation thru
the foramen magnum. Vessels tear, almost always lethal, also VERY serious.
Duret's Hemorrhage
-
Causes of Duret's hemorrhage
Subdural hematoma, tumor, trauma
-
Most common cause of CVA
infarct
-
Most common populatino for an infarct
Males,7th decade
-
Most common cause of an infarct
Cerebral atherosclerosis
-
Type of necrosis involved with an infarct
Liquefactive
-
Vessel most commonly causing an infarct
MCA
-
What type of reactions occur at the MCA?
Gliotic reactions, NOT fibrosis
-
Most common cause of primary brain parenchymal hemorrhage
HTN
-
minute aneurysms in basal ganglia from
hypertension
Charcot-Bouchard microaneurysms; seen in primary brain parenchymal hemorrhage
-
Most common location for a parenchymal hemorrhage
Basal ganglia (particularly putamen)
-
Parenchymal hemorrhage sx
N,V,HA,LOC, speech problems
-
Most common cause of SAH
rupture of a saccular aneurysm
-
Where are most berry aneurysms located and when is the greatest risk of rupture?
- most commonly found at arterial bifurcations, such as junction of anterior cerebral and anterior communication arteries
- Greatest risk of rupture 4-7 cm in diameter
-
Who is at an increased risk for developing renal aneurysms?
Adult PCKD
-
What are the most common vascular malformations?
AV malformations
-
AV malformations are most commonly found where?
The cerebral hemisphere, typically temporal lobe
-
haphazardly arranged blood vessels
AV malformation
-
Most common areas of bleeding in the brain
SAH, epidural, subdural
-
Most common cause of epidural hematoma
trauma
-
Hematoma associated with skull fracture
Epidural
-
Hematoma associated with MMA
epidural hematoma
-
Hematoma with venous blood
Subdural
-
MOA of subdural hematoma
Brain bouncing around and pulling on BRIDGING veins
-
Brain injury associated with rapid deceleration and retraction and shearing of axons
Diffuse axonal injury
-
What is the difference between the two types of brain contusions?
Coup-injury to vein directly beneath and impact sight. Usu. Stationary head being hit by a moving object
o Contra-coup-opposite, moving head hitting astationary object.
-
Optic nerve sheath damage and retinal hemorrhage are signs of what?
Shaken baby syndrome
-
What brain injury results due to shearing forces, such as being punched in back of head, or karate chop to back of neck?
Vertebral artery laceration
-
Most common cause of neonatal meningitis
Group B Strep, e coli
-
Most common cause of meningitis in >6mo
H flu (but not anymore due to vaccination, it's now strep pneumo
-
Most common cause of meningitis in older children, adolescents, young adults
Neisseria meningitidis
-
Most common cause of meningitis in older adults
strep pneumo
-
What populations do you find listeria monocytogenes in?
elderly, neonates, and immunocompromised
-
Purulent exudate at base of brain in haemophilus influenzae infections obscuring circle of willis
H flu meningitis
-
Edematous brain and spinal cord with neutrophils and fibrin
Bacterial meningitis
-
Increased protein and decreased glucose in CSF
Bacterial meningitis
-
Most common viruses causing viral meningitis
mumps, echovirus, coxsachievirus
-
CSF: protein slightly elevated, glucose normal, mostly lymphocytes
Viral meningitis
-
Most comon causes of chronic meningitis
CSF: protein slightly elevated, glucose normal
-
most common locations for a brain abscess
Occur usually in the cerebral hemispheres, Temporal lobe, frontal lobes (niddle ear and sinus involvement)
-
multiple focal lesions in the gray matter
toxoplasmosis
-
Perivascular inflammation: lymphocytes, plasma cells
Viral encephalitis
-
Microglial nodules
Viral encephalitis
-
infects oligodendroglia causing areas of demyelination
Progressive multifocal leukoencephalopathy
-
Where in the brain does HSV infect in vira encephalitis?
Temporal lobes and orbital/frontal areas
-
Where in the brain does CMV affect in viral encephalitis?
Ependymal surfaces (lining of the ventricles)
-
Where in the brain does HIV affect in viral encehpalitis?
Brain atrophy, involvement of white matter and basal ganglia with multinucleated giant cells
-
Causes of spongiform encephalopathies
CJD, kuru, mad cow dz
-
Vacuoles in gray matter with rapidly progressive dementia, gait abnormalities
Spongiform encephalopathies
-
Most common demyelinating disease
MS
-
Most common age affected with MS
18-40 yo
-
Common sites for plaques in MS
periventricular white matter, optic nerves, white matter of spinal cord
-
Visual disturbances, paresthesias, spasticity, speech disturbances, and gait abnormalities
MS
-
Butterfly wing-red area
MS
-
Thiamine deficiency resulting in peripheral
neuropathy
Wernicke Encephalopathy
-
Rapid onset of confusion, paralysis of
extraocular muscles and ataxia
Wernicke encephalopathy
-
Hemorrhage in mammilary bodies, thalamus, gray matter around the cerebral aqueduct
Wernickes
-
What results from untreated Wernickes?
Korsakoff's Psychosis
-
Inability to form new memories or retrieve old ones
Korsakoff's psychosis
-
Accompanied by confabulation-forget parts of the story and will fill in with s/t else, won’t make sense
Korsakoff's psychosis
-
Technically can only be dx after death
Alzheimers
-
Most common cause of dementia in elderly
Alzheimers
-
Hydrocephalus ex vacuo: dilation of ventricles from loss of parenchyma
Alzheimers
-
What brain weight is an indication of Alzheimers?
1000 g
-
coarse, tortuous neurites in cerebral cortex with a central amyloid core
Senile plaques, seen with Alzheimers
-
filamentous aggregates within cytoplasm of neurons
Neurofibrillary tangles, seen with Alzheimer's Disease
-
Substantia nigra and locus ceruleus are depigmented in most cases
Parkinsons
-
laminated intracytoplasmic inclusions in some neurons
Lewy bodies, seen with Parkinsons
-
Involves extrapyramidal motor system
Huntington disease
-
Atrophy of caudate nucleus, putamen, and globus pallidus; Dilation of ventricles; Neuropsychiatric disturbances occur; Increased risk of suicide
Huntington's Dz
-
Degenerative disorder involving the upper and lower motor neurons of the pyramidal system
ALS
-
Most common cause of death in ALS
pneumonia, followed by respiratory insufficiency or infections
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