Pathoma Flashcards
Most common cause of meningitis in neonates
Group B strep
E. coli
Listeria monocytogenes
Most common cause of meningitis in nonvaccinated infants?
H. influenza
Most common virus causing meningitis?
Coxsackie virus
Fungi causes meningitis in the following group of individuals
immunocompromised individuals
Most common cause of meningitis in children and teenagers? In adults and the elderly?
N meningitidis; S pneumoniae
How much glucose is usu in the CSF?
2/3 of plasma glucose levels (ex: if blood glucose is 100g, glucose in CSF would be ~66)
At what level should you put the needle to do a lumbar puncture?
L4/L5 (spinal cord ends at L2)
CSF analysis: Neutrophils with low CSF glucose
bacterial meningitis
CSF analysis: Lymphocytes with normal CSF glucose
viral meningitis
CSF analysis: Lymphocytes with decreased CSF glucose
fungal meningitis
What is the difference b/w a meningocele and a meningomyelocele?
meningocele: protrustion of the meninges
meningomyelocele: protrusion of meninges and spinal cord
Presents as a dimple or patch of hair overlying the vertebral defect
spina bifida
Damage to the anterior motor horn; present with lower motor neuron signs - flaccid paralysis with muscle atrophy, fasciculations, weakness with decreased muscle tone, impaired reflexes, and negative Babinski sign
poliomyelitis
Presents as a sudden headache (“worst headache of my life”) with nuchal rigidity; most frequently due to rupture of a berry aneurysm
subarachnoid hemorrhage
Collection of blood b/w dura and skull
epidural hematoma
Why do you get a lens shaped bleed with epidural hematoma?
because the dura is so tightly adhered to the skull, so it remains attached at the two edges
Lucid intervals; “talk and die syndrome”
epidural hematoma
What usually causes subdural hematoma? What tears in subdural hematoma?
trauma; bridging veins that lie between the dura and the arachnoid
What shape do subdural hematomas take on?
crescent shape
Involves displacement of the cerebellar tonsils into the foramen magnum
tonsillar herniation
Displacement of the cingulate gyrus under the falx cerebri
subfalcine herniation
Displacement of the temporal lobe uncus under the tentorium
uncal herniation
What 3 complications are associated with uncal herniation?
- compression of CN 3 leading to a blown pupil and the eye moving “down and out”
- compression of posterior cerebral artery leads to infarction of occipital lobe
- rupture of paramedian artery can lead to Duret (brainstem) hemorrhage
Increased CSF resulting in dilated ventricles; presents with a) urinary incontinence, b) gait instability, and c) dementia
hydrocephalus
Tumors in adults usu occur (blank) the tentorium, while tumors in kids usu occur (blank) the tentorium
above; below
Malignant, high-grade tumor of astrocytes;
most common primary malignant CNS tumor in adults;
usu in the cerebral hemisphere;
crosses the cerebral hemispheres (butterfly lesions)
glioblastoma multiforme
What would you see histologically in glioblastoma multiforme?
regions of necrosis surrounded by tumor cells (pseudopalisading) and endothelial cell proliferation
Because glioblastomas are tumors of astrocytes, they will be (blank) positive
GFAP
Benign tumor of arachnoid cells; most common BENIGN CNS tumor in adults; more commonly seen in women; imaging reveals a round mass attached to the dura
meningioma
What would you see histologically in meningiomas?
whorled pattern of growth and psammoma bodies
Benign tumor of Schwann cells; involves cranial nerves, most frequently CN 8; tumor cells are S-100 positive; associated with NF2
Schwannomas
Malignant tumor of oligodendrocytes; calcified white matter, usu in the frontal lobe
oligodendroglioma
What would you see histologically with oligodendroglioma?
fried-egg appearance of cells
Benign tumor of astrocytes; most common CNS tumor in kids; usu in the cerebellum
pilocytic astrocytoma
Because a pilocytic astrocytoma is a tumor of glial cells it will be (blank) positive
GFAP
What would you see on imaging if you had a pilocytic astrocytoma? What about histologically?
cystic lesion with mural nodule (something growing off of the wall of the tumor); Rosenthal fibers
Malignant tumor derived from granular cells of the cerebellum; usu arises in children; small, blue round cells; Homer-Wright rosettes
medulloblastoma
Malignant tumor of ependymal cells; usu in children; most commonly in 4th ventricle (in kids); pseudorosettes (surrounding vasculature)
ependymoma
