epidural hematomas - bleeding where?
btwn skull and dura
which artery is involved w epidural hematomas?
- middle meningeal artery
- usually temporal
due to which blood vessel?
- in dubdural space
- bridging veins btwn brain and the large dural sinuses
- it's not an immediate emergency, so by the time it's a problem pts often forgot about the incident
subarachnoid hemorrhage is caused by...?
usually trauma and rupture of a preexisting arterial aneurism
vascular malformations are due to..?
imcomplete and/or abnormal reslution of embryonic vasculature
most common aneurism
saccular ("berry") aneurisms - seenin 5-6% of the population
saccular/berry aneurisms are usually where?
- at bifurcation of vessels, usually in the middle cerebral artery and its branches
- however, those in the ant. ecrebral and ant. communicating artery are more prone to ruputre
cerebral (non-traumatic) hemorrage
a collection of usually bloody fluid within brainstem or cerbral hemispheres (aka: stroke)
most common cause of non-traumatic hemorrhage
- hypertensive hemorrhage
- occurs most frequently in basal ganglia due to ruputre of blood vessels whose walls have been previously damaged by chronic hypertension or hypertensive microaneurism
diff between hemorrhages and infarcts
hemor - not confined to an arterial distribution and tend to compress the brain parenchyma, not destroy it.
infarction results from
loss of blood supply with ensuing necrosis due to 1 - vascular thrombosis or 2 - embolism
- related to abnormal flow of cerebrospinal fluid, increased CSF vol.
- can be due to problems with production, but more often due to problems w reabsorption
blockages are where??
- noncom: blockage is within brain
- comm: blockage is in subarachnoid space
3 causes of hydrocephalus
- 1. overproduction of CSF
- 2. inability of acracnoid villi to transfer CSF to venous drainage
- 3. blockage of CSF pathways (noncom - blockage in brain, or comm - blockage in subarachnoid space)
bacterial infection caused by e. coli, h. influenza, n. meningitidis, and strep. pneumonia
meninges fill up with purulent exudate increasing pressure, neutrophils, and protein, and decreasing glucose
symptoms: agitation, headache, photophobia , stiff neck,
result of bacterial infection carried by bloodstream from sinus, ear, or mastoid infections
first it's accute, with neutrophil infiltration and liquefactive necrosis w extensive cerebral edema, then fibroblasts wall of the nccrotic area and dead tissue is removed
a complication of systemic viral disease and aids
any inflammation of gray matter of spinal cord, viral
encephalitis caused by rabies virus
what chromosome and protein are involved?
what happens to meninges
death is often secondary to __
- chrom 21, amyloid protein
- meninges thicken
- "gyri atrophic with dilation of ventricles due to cortical atrophy"
to respiratory infections
- amylotrophic lateral sclerosis
- degenerative disease, a wasting of the extremities, while sensory and mental function remain intact
- degeneration of upper motor neurons in the CNS
- damage to corticospinal tracts and anterior horn cells ---> denervation atrophy of muscle groups
- chorea - sudden twitches and jerks
- autosomal dominant disease
- appears in 4th decade
- atrophy of caudate and putamen nuc
3 CNS neoplasms w neuroglial origin
- astrocytoma ---> siezures, motor deficits, mental changes
- oligodendroglioma ---> siezures
- ependymoma --->most frequently in 4th ventricle
CNS neoplasm of meningial origin
- meningioma - slow growing, benign, may or may not be symptomatic (headach, focal seizures, visual disturbances)
- prognosis depends on accessibility to surgical removal
CNS neoplasm of metastatic origin
much worse than meningeal origin
- primary sites in order of frequency:
- lung, breast, melanoma, kindey, GI
symptoms: headache, siezure
- PNS problem
- degen in distal segment of a transected nerve w buildup of organelles in the proximal and distal agonal stums, and atrophy of schwann cells replaced by fibrose tissue
a nerve is cut, stuff builds up around the stumps, the myelin turns to fibrotic tissue
<Sam Waller -- short guy with big beautiful hair>
- a PNS problem
- distal axonopathy (dying back) while proximal axon is intact
- involves toxic and metabolic neruopoathies
- regeneration is possible if the cause is removed
a PNS problem of damage in myelin sheaths
- a PNS problme
- it's the most common form of symmetrical polyneruopath
- can involve sensory and autonomic nerves w extensive segmental dmyelination secondary to axonal degneration
- PNS trouble
- an autoimmune disorder w progressive ascending motor paralysis
- may affect spinal and cranial nerves
- preceded by viral infections
- char. by segmental demyelination