Chapter 17 - CNS Flashcards
What is associated with Neural Tube Defects?
Low folate levels PRIOR to conception.
Symptoms of anencephaly?
Polyhydramnios…
Cause of Dandy-Walker malformation and presentation?
Due to congenital failure of the cerebellar vermis. Results in massively dilated 4th ventricle, with absent cerebellum…
What other defects are associated with Arnold-Chiari Malformation Type II?
Meningomyelocele and syringomyelia
What is syringomelia and where does it most often occur?
Cystic degeneration of the spinal cord. Most often occurs at C8-T1, spares dorsal columns but compresses spinothalamic tract in the anterior white commissure.
“Floppy Baby” Syndrome?
Werdnig-Hoffman Disease (inherited degeration of the anterior motor horn.)
ALS involves the degeneration of what structures?
UMN AND LMN…
Cause of familial ALS?
Superoxide dismutase (SOD1) mutation…
Cause of Friedreich Ataxia?
Expansion of trinucleotide repeat (GAA) in frataxin gene.
Cardiac association with Friedreich Ataxia?
Hypertrophic Cardiomyopathy
Most common cause of bacterial meningitis in newborn?
Group B strep, E coli, and Listeria
Most common cause of bacterial meningitis in children/teenagers?
N meningitidis
Most common cause of bacterial meningitis in adults and elderly?
Strep pneumonia
Most common cause of bacterial meningitis in non vaccinated kids?
H influenza
CNS defect seen with DM, or insulinomas…?
Global Cerebral Ischemia, due to repeated episodes of hypoglycemia.
How does moderate global cerebral ischemia present hystologically?
Cortical Laminar Necrosis (triangular appearance) from damage to the pyramidal nuerons of layers 3, 5, and 6.
Red neurons are seen how long after an ischemic stroke?
12 hours post infarction.
Coagulative necrosis is seen how long after ischemic stroke? And is followed by what?
24 hours, followed by neutrophils (1-3 days), nicroglial cells (4-7 days), and granulation tissue (2-3 weeks)
What are high risk groups for berry aneurisms?
Marfan syndrome, ADPKD, and Ehlers-Danlos
Classic cause and symptoms of an epidural hematoma
Fracture of temporal bone leading to a rupture of middle meningeal artery. Presents with Lens-shaped lesion on CT. Lucid interval may precede signs.
Classic cause and symptoms of subdural hematoma
Due to tearing of bridging veins. Presents with a crescent-shaped lesion of CT and progressive neurologic signs.
What artery is often compressed with a subfalcine herniation?
The ACA!
Metachromatic Leukodystrophy
Due to deficiency in arylsulfatase (AR), which is necessary for the degradation of myelin. Accumulates in the lysosomes of oligodedrocytes…
Krabbe disease
Due to deficiency of galactocerebroside b-galactosidase (AR). Galactocerebroside accumulates in macrophages. Also necessary for production/maintenance of myelin.
What is lost in Multiple Sclerosis?
CNS myelin AND oligodendrocytes.
What is found in the CSF of patients with Multiple Sclerosis?
Increased lymphocytes, increased Ig with oligoclonal IgG bands, and myelin basic protein.
Cause of Subacute Sclerosing Panencephalitis?
Slowly progressing, persistent infection by measles virus.
Cause of Progressive Multifocal Leukoencephalopathy?
JC virus infection of oligodendrocytes. Usually immunosuppressed.
Cause and symptoms of central pontine myelinolysis?
Due to rapid correction of hyponatremia. Causes focal demyelination of the pons –> Locked in syndrome.
Do you see focal neurological deficits early in Alzheimers?
NO
What gene is protective and what is associated with risk for alzheimer’s?
ApoE2 protective, ApoE4 increased risk. Also mutations in presenilin1/2 linked to familial Alzheimer’s.
What histologic changes common in Alzheimers?
Extracellular Ab amyloid deposition (Aa normal cleavage) and neurofibrillary tangles (hyperphosphorylated tau protein intracellular!)
Histologic characteristics of Pick Disease?
Intracellular round aggregates of tau protein (Pick bodies).
What illicit drug was early linked to Parkinson’s?
MPTP
Histology of Parkinson’s?
Loss of pigmented neurons in the Substantia Nigra and round, eosinophilic inclusions of a-synuclein in affected neurons.
Cause of Huntington Disease?
Degeneration of GABAergic neurons in the caudate nucleus due to expanded CAG repeats in the huntington gene of chrom. 4
Common complication of Normal Pressure Hydrocephalus?
Stretching of the Corona Radiata! Presents as ‘wet, wacky, and wobbly’
Common sites of primary tumor to metastasize to the brain?
Lung, breast, and kidney
Histology of Glioblastoma Multiforme?
Pseudopalisading tumor cells surrounding areas of necrosis. Tumors are GFAP positive (tumor of Astrocytes)
Histology of Meningioma?
Whorled pattern with psammoma bodies. Tumor of Arachnoid Cells
Histology of Schwannoma?
S-100 positive tumors at the cerebellopontine angle. Tumor of Schwann cells…
Histology of Oligodendroglioma?
Fried egg appearance. Often calcified. Malignant tumor of oligodendrocytes.
Histology of Pilocytic Astrocytoma?
Rosenthal fibers (thick eosinophilic processes of astrocytes) and eosinophilic granular bodies. GFAP positive (Childhood, benign tumor of astrocytes).
See cystic lesion with a mural nodule on imaging
Histology of medulloblastoma?
Homer-Wright rosettes (blue cells wrapped around pink areas), small, round blue cells. Malignant childhood tumor of the neuroectoderm…
Histology of Ependymoma?
Perivascular pseudorosettes. Malignant childhood tumor of ependymal cells…
Histology of Craniopharyngioma?
Cacifications derived from tooth like remnants of Rathke’s pouch. Can present as bitemporal hemianopsia due to compression of the optic chiasm…
