Pavlick: Meninges and CSF flow Flashcards
layers of the head
SCALP over DAP
(skin, CT, aponeurosis, loose CT, pericranium)
(Dura, arachnoid, pia)
Pachymeninges
“thick” —-dura mater
Leptomeninges
“thin”—-arachnoid and pia mater
___space b/t dura and calvaria
epidural
____space b/t dura and arachnoid mater
subdural
skull cap
calvaria
bleed caused by damage to middle meningeal a.
Epidural
epidural bleed
Union of temporal, frontal, parietal and sphenoid bones
Pterion
due to fracture of ______ that causes damage to middle meningeal a.
Pterion
results from rupture bridging meningeal veins
subdural bleed
onset of symptoms can be much slower (e.g., several hours) due to lower pressure control
subdural bleed
____ mater is a double layer
dura mater
separates cerebral hemispheres
Falx cerebri
separates cerebellum hemispheres
Falx cerebelli
“tent” over cerebellum
Tentorium cerebelli
the dura outer layer creates ______ sinuses
venous
venous drainage starting at cavernous sinus
venous drainage starting at inferior sagittal sinus
venous drainage starting at superior sagittal sinus
Symptoms include:
Headache
Blurred vision
Seizures
Coma
central(cerebral) venous sinus thrombosis
most common site of cerebral venous sinus thrombosis
superior sagittal sinus
“spider mother”
Cobweb-like appearance between dura and pia mater
arachnoid mater
____ space lies above arachnoid
subdural
____ space lies below arachnoid
subarachnoid space
span entire space and attach to pia mater; act to suspend brain to reduce weight but still provide some stability; “bungee cords”
Arachnoid trabeculae
contains CSF and vasculature
subarachnoid space
site of CSF diffusion from subarachnoid space into dural sinus
Arachnoid granulations
“frozen chicken”
“5 star”
(basilar(subarachnoid)cisterns)
subarachnoid hemorrhage
Occupies potential space between arachnoid and pia mater
subarachnoid
second most common cause of rupture of arterial berry aneurysm
subarachnoid hemorrhage
Under arterial pressure—–higher pressure (quick and severe onset)
subarachnoid hemorrhage
“thunderclap headache”—-worst headache of your life
subarachnoid hemorrhage
Innermost meningeal layer which closely adheres to the brain and spinal cord
Pia mater
The spinal cords version of bungee cords so its not swinging around
pia mater
top: conus medullaris
middle: cauda equina
bottom: filum terminate interum
anchor spinal cord laterally (extension of pia mater)
denticulate ligaments
extension of pia mater that anchors spinal cord caudally
Filum terminale internum
tumor arising from meninges (meningothelial cells)
Meningioma
hollow spaces which contain and allow the flow of CSF (system looks like a halo spaceship)
ventricles
produces CSF
choroid plexus w/in ventricles
Site for very selective exchange of ions and nutrients (similar to glomerular filtrate/kidney)
choroid plexus
CSF flows from lateral ventricles through ______ to third ventricle
foramina of monro (interventricular formamina)
CSF flows from third ventricle to the fourth ventricle through what
cerebral aqueduct
through what 2 things does CSF flow through to get from brainstem to spinal cord (subarachnoid space)
Foramen of Magendie (medial)
Foramen of Luschka (lateral)
will be reabsorbed through arachnoid granulations and cycle back through
CSF
“water in the head”
hydrocephalus
increased CSF within the ventricles can be due to ______ flow of CSF
blocked
Can be resolved by placing a shunt to relocate CSF to abdominal cavity for reabsorption
hydrocephalus
aqueductal stenosis is most common cause
hydrocephalus
often observed with this is dilation of ventricles
hydrocephalus
loss of brain ___ leads to increased ventricular size (Ex-vacuo type hydrocephalus)
parenchyma
Non-communicating (“obstructive”)—-> impairment of CSF flow ___________ ventricular system
within
Communicating (“non-obstructive”)—-> impairment of CSF flow ___________ of ventricular system
outside
Normal Pressure (intracranial hypertension)—-> ____ CSF production
increased
HA and elevated ICP but NO lesion present or ventricular dilation
Pseudotumor cerebri
signs of hydrocephaly but imaging is normal
Pseudotumor cerebri
Symptoms:
Vision changes
Dizziness, nausea/vomiting
Stiff neck
Tinnitus
Cognitive change
hydrocephalus
can be acquired via lumbar puncture (L3-L5) and constituents analyzed for diseases
CSF
normal CSF
Xanthochromia
RBC degeneration in CSF (hemorrhage)
custard like
meningitis (elevated WBCs)
traumatic tap
refers to inflammation of the soft meninges (pia and arachnoid) and can be classified into several types
Leptomeningitis
fever
HA/stiff neck
altered mental status
Brudzinski’s sign/Kernig’s sign
neutrophils in staining
Meningitis
flexion of both hips and knees when neck is passively flexed
Brudzinski sign
resistance to full extension of leg at knee when hip is flexed
Kernig sign
most common causes of neonatal meningitis
Group B strep
E. coli
Listeria
2 most common causes of meningitis in kids and adults
S. Pneumoniae
N. Meningitidis
Observe opisthotonos (looks like baby is possessed)
neonatal meningitis
Community acquired
Newborns acquire through maternal genital flora (on the way out)
Opisthotonos
Group B strep meningitis
gram + cocci
beta hemolytic
meningitis in new borns
group B strep
Spread through respiratory secretions (aerosolized)
Risk factors include age <5 and >65 and immunocompromising conditions (e.g., HIV, Sickle-cell disease)
Strep pneumoniae
gram + diplococci
alpha hemolytic
MOPS
Strep pneumoniae
MOPS from infection with strep pneumoniae
meningitis
otitis media
pneumonia
sinusitis
gram - bacilli
ferments lactose
capsular K antigen (neonatal ____ )
EHEC
ETEC
E. coli; neonatal meningitis
gram + bacilli
“rocket tails” moves intracellularly
Acquired by ingesting improperly processed deli meats and unpasteurized dairy products
pregnant women
Listeria
most common cause of bacterial meningitis before HIB vaccine
can cause cellulitis
Haemophillus influenza type b
in children, causes adrenocortical hemorrhage leading to DIC and shock
Neisseria meningitis
Adrenocortical hemorrhage leading to DIC and shock in children
Waterhouse-Friedrichsen syndrome
Outbreaks associated with young adult army recruits and colleges
N. meningitis
results from untreated syphilis infection
neurosyphilis
Thickened meninges
Obliterative endarteritis
Ependymal granulations
(neurosyphilis)
meningitis from syphils
spirochetes on darkfield microscopy
S shaped on HandE
treat infection with Penicillin G
Treponema pallidum
aseptic (viral) meningitis is most commonly caused by _____
enteroviruses
difference b/t viral and bacterial meningitis
treat bacterial w/ antibiotics
Caused by slow-growing organisms which cause symptoms to appear weeks to months post-infection
chronic meningitis
Caseating granulomas in respiratory
Overtime, can penetrate BBB and irritate meninges
Mycobacterium tuberculosis
form necrotic, expanding colonies called Rich foci
Mycobacterium tuberculosis (tuberculosis meningitis)
immunocompromised states
Encapsulated yeasts with narrow neck buds in subarachnoid space
causes chronic meningitis
cryptococcal spp.
encapsulated yeast from subarachnoid space into basal ganglia; since this most commonly occurs in basal ganglia, will see movement disorders/tremors
chronic meningitis from cryptococcal spp.
Symptoms brain tumors will include ____________________________ and typically a specific function deficit which can help localize it
increased ICP
most common spinal cord tumor
Ependymoma
common in posterior fossa of children
Ependymoma
Ependymomas originate from ______ cells
radial glial cells (ependymal cells)
Form “____________________” around blood vessels instead of a lumen
pseudorosettes
Rare, neuroepithelial intraventricular tumor
Typically found in Foramen of Monro, fornix
Affects children and young adults
central neurocytoma
rare neuroepithelial tumor that stains for synaptophysin, chromogranin, and NSE
central neurocytoma
2 main age related changes that occur within brain
ventricular dilation
calcification of arachnoid granules
More rapid progression of ______in neurodegenerative or atrophying conditions:
Alzheimer’s
Huntington’s disease
ventricular dilation
Leads to decreased reabsorption of CSF and subsequent hydrocephalus
calcification of arachnoid granules