CNS Flashcards
neural tube defect: no cerebral hemispheres
anencephaly
neural tube defect: meninges and brain don’t close
encephalocele
neural tube defect: meninges don’t close
cranial meningocele
neural tube defect: meninges and spinal cord; spina bifida
meningomyelocele
neural tube defect: meninges; spina bifida
spinal meningocele
neural tube defect: vertebral arches do not close; no herniation; hairy patch
spina bifida occulta
disorders of forebrain development: brain is not divided hemispheres
holoprosencephaly
holoprosencephaly can result in …
cyclopia
disorders of forebrain development: many small gyri
polymicrogyria
disorders of forebrain development: no gryation
lissencephaly
disorders of forebrain development: brain cells not divided in organized layers
cerebral cortical dysplasia
“water on the brain” -too much CSF for whatever reason. usually obstruction in flow
hydrocephalus
posterior skull too small, structures impede CSF flow
Arnold-Chiari malformations
cystic cerebellar vermis (the middle part) causes outflow obstruction of CSF
Dandy-Walker malformation
also known as “Phakomatoses”; malformations and non-neoplastic and neoplastic growths of nervous system, skin, and other systems
neurocutaneous syndromes
gliomas and meningiomas; NF1 tumor suppressor gene; cafe au lait; lisch nodule
neurofibromatosis I
germinal matrix hemorrhage- common in extreme …
prematurity
usually idiopathic, but can be caused by an assault on the brain (metabolic, infectious, trauma); lesion is often in temporal lobe; causes periods of clonus with unconsciousness
epilepsy
increased ICP; blood-brain barrier not intact; fluid seeps out of vessels; little lymphatic drainage
vasogenic cerebral edema
increased ICP: cells themselves swell with fluid due to injury
cytotoxic cerebral edema
increased ICP: cerebrum slips under the “falx”-a fold of dura at the top
subfalcine herniation
increased ICP: cerebrum slips under the “tentorium cerebelli”-a fold of dura at the sides, also known as “Uncal” from the actual area that is affected
transtentorial herniation
increased ICP: tonsils of cerebellum slip through foramen magnum
tonsillar herniations
Increased ICP: buildup of the CSF in ventricles, typically due to decreased outflow
hydrocephalus
in hydrocephalus: if cranial sutures are fused, results in …
big ventricles and compressed brain matter
in hydrocephalus: if sutures are open, results in …
increased head size
one treatment strategy for hydrocephalus is … where a conduit is placed into the ventricles to drain fluid, either to an outside container or to peritoneal cavity in the abdomen
shunting
most due to atherosclerotic vascular disease; blurring between gray and white matter; red dead neurons; gliosis
cerebral infarcts
perfusion to entire brain is inadequate; results in ischemia
global hypoxic-ischemic encephalopathy
most common reason for intracranial hemorrhages
hypertension
likely due to acquired weakening in wall; found in circle of willis; most at bifurcations; can cause subarachnoid hemorrhage;
saccular (or berry) aneurysms
patients experience a pass out -> “lucid interval” -> rapid decompensation; often caused by rupture of middle meningeal artery with accompanying skull fracture; characteristic “lens” shape on CT scan; requires emergent drainage
epidural hematoma
acute or chronic; not a dramatic because of slower venous bleeding rate; often occurs in elderly and may be diagnosed as dementia; “crescent” shaped bleeding
subdural hematoma
characteristic whiplash motion: auto accident; axonal swellings: spheroids
diffuse axonal injury
contusion: the actual impact
coup
contusion: the brain banging against the opposite side
counter coup
most common demyelinating disease; plaques in white matter
multiple sclerosis
most common cause of dementia in the elderly; amyloid plaques and neurofibrillary tangles
alzheimer’s disease
beta-amyloid protein
amyloid plaques
tau protein
neurofibrillary tangles
loss of pigmented neurons in substantia nigra; movement disorder; lewy bodies
parkinson’s
involuntary writhing movements: chorea; depression and dementia; expansion of CAG triplet; atrophy of caudate nucleus and cortex
huntington disease
degeneration of upper and lower neurons; muscle atrophy and weakness spasticity; bunina bodies
amytrophic lateral sclerosis
very malignant; most common in kids; occurs in cerebellum; small round blue cells forming Homer Wright pseudorosettes
medulloblastoma
glial tumor: necrosis and pseudopallasading; ring enhancing lesion; microvascular proliferation
glioblastoma
glial tumor: commonly adulthood; cerebral hemispheres; “fried egg appearance”, “satellitosis”
oligodendroglioma
glial tumor: mostly in ventricles or central canal of spinal cord; perivascular pseudorosettes
ependyomas
arise from cells covering brain and spinal cord; psammoma bodies
meningioma
most common tumor of the brain
metastatic tumor
inflammation limited to the meninges and the subarachnoid space; nuchal rigidity, photophobia and headache
meningitis
meningitis: usually bacterial; E coli, meningococcus
acute pyogenic meningitis
meningitis: viral; ECHO, coxsackie, EBV, HSV
acute lymphocytic meningitis
meningitis: prototype: M. tuberculosis
chronic meningitis
most due to bacteria from nasopharynx via bloodstream; congested meninges; exudate in subarachnoid space; brain tissue itself not infected
acute purulent meningitis
encephalitis: infection elsewhere travelling via bloodstream; adjacent infections in ear and sinuses
abscess
encephalitis: caseating granuloma
tuberculosis
encephalitis: typically AIDS patients, ring enhancing lesion
toxoplasmosis
encephalitis: most common cause of sporadic encephalitis in US; temporal lobes and orbital frontal areas
herpes simplex virus type 1
encephalitis: classi negri bodies in neurons; symptoms occur too late
rabies
associated with abnormal prion protein; Creutzfeldt Jakob Disease
transmissible spongiform encephalitis
highly resistant to heat and most disinfectants; abnormally folded forms cannot be cleared from the brain and cause toxicity
prion protein
