CNS Flashcards
How is Neural tube defects detected
Elevated AFP
Interventricular foramen of Monro drains
CSF from Lateral ventricles into the 3rd ventricle
Foramina of Magendie and Luschka drain
CSF from 4th ventricle into subarachnoid space
Dandy-Walker malformation is
Congenital failure of the cerebellar vermis to develop
Dandy-Walker malformation presents as
Massively dilated 4th venticle with an absent cerebellum
What level does Syringomyelia occur
C8-T1
Syringomyelia presents as
Loss of pain and temperature with sparing of fine touch and position sense (cape like) due to involvement of anterior white commissure of the spinothalamic tract
Poliomyelitis is
Damage to the anterior motor horn due to poliovirus infection
Poliomyeltis presents with
Lower motor neuron signs:
- Flaccid paralysis with muscle atrophy
- Fasciculations
- Weakness with decreased muscle tone
- Impaired reflexes
- Negative Babinski
Werdnig-Hoffman disease genetic
AR
Werdnig-Hoffman disease is
Inherited degeneration of the anterior motor horn
Werdnig-Hoffman disease presents
Same as poliomyelitis
Floppy baby
ALS is
Degenerative disorder of upper and lower motor neurons of the corticospinal tract
Upper motor neuron signs
Spastic paralysis with hyperreflexia
Increased muscle tone
Positive Babinski sign
Familial ALS is due to
Zinc-copper superoxide dismutate (SOD1) mutation
Freidreich ataxia is
Denerative disorder of the cerebellum and spinal cord
Friedreich ataxia is due to
AR GAA repeat in the Frataxin gene
Degeneration of cerebellum leads to
Ataxia
Degeneration of multiple spinal cord tracts seen in Friedreich ataxia leads to
- Loss of vibratory sense and proprioception
- Muscle weakness in lower extremities
- Loss of DTR
Friedreich ataxia associated with
Hypertrophic cardiomyopathy
Spinothalamic tract
Pain and temperature sensations
Dorsal column-medial lemniscus
- Pressure
- Touch
- Vibration
- Proprioception
Lateral corticospinal
Voluntary movement
Hypothalamospinal
Sympathetic input of the face
First order neurons of Spinothalamic tract
- Peripheral nerves to posterior horn
- Cell body is in dorsal root ganglion
Second order neurons of spinothalamic tract
From posterior horn, immediately crosses over in anterior white commissure and ascends via spinothalamic tract to thalamus
First order neurons of dorsal column-medial lemniscus
Peripheral nerves to medulla via dorsal column
Cell body is in dorsal root ganglion
Second order neurons of Dorsal column-medial lemniscus
From medulla crosses over and ascends via medial lemniscus to thalamus
Most common cause of meningitis in Neonates
- Group B Strep
- E. coli
- Listeria monocytogenes
Most common cause of meningitis in Children and teenagers
N. meningitidis
Most common cause of meningitis in adults
S. pneumoniae
Most common cause of meningitis in nonvaccinated infants
H. infleunza
CSF finding ins bacterial meningitis
PMN with decrease CSF glucose
CSF findings in viral meningitis
Lymphocytes with normal CSF glucose
CSF findings in fungal meningitis
Lymphocytes with decreased CSF glucose
Subfalcine herniation involves
Displacement of the cingulate gyrus under the falx cerebri
How does Subfalcine herniation lead to infarct
Compresses anterior cerebral artery
Uncal herniation involves
Displacement of the temporal lobe uncus under the tentorium cerebelli
Uncal herniation causes
- Compression of CN3: eyes down and out
- Compression of posterior cerebral artery: infarction of occipital lobe (contralateral homonymous hemianopsia)
- Rupture of paramedian artery: Duret (brainstem) hemorrhage
Metachromatic leukodystrophy is due to
a deficiency of arylsulfatase
Metachromatic leukodystrophy genetics
AR
Krabbe disease
Leukodystrophy due to deficiency of galactocerebroside β-galactosidase
Krabbe disease genetics
AR
Adrenoleukodytrophy due to
Impaired addition of coenzyme A to long chain FA
Adrenoleukodystrophy genetics
X-linked
What HLA is MS
HLA-DR2
Subacute sclerosing panencephalitis is due to
Persistent infection of the brain by Measles virus
Progressive multifocal leukoencephalopathy is due to
JC virus infection of oligodendrocytes
Progressive multifuocal leukoencephalopathy presents with
Rapidly progressive neurologic signs
Central pontine myelinolysis is due to
Rapid intravenous correction of hyponatremia
Central pontine myelinolysis presents as
Locked-in
Pick disease is
Degnerative disease of the frontal and temporal cortex
Pick bodies are
Round aggregates of tau proteins in neurons of the cortex
Lewy bodies are
Inculsion of α-synuclein in parkinsons
Huntington genetic
AD CAG repeat
Normal pressure hydrocephalus triad
- Urinary incontinence (wet)
- Gait instability (wobbly)
- Dementia (wacky)
Creutzfeldt-Jakob disease presents
Spongiform
- Rapidly progressive demintia with ataxia
- Startle myoclonus
Meningioma is
Benign tumor of arachnoid cells
Meningioma imaging reveals
Round mass attached to dura that does not invade the cortex
Meningioma Histology shows
Whorled pattern
Psammoma bodies
Which CNS tumor expresses estrogen receptors
Meningioma
Schwannoma presents with
Loss of hearing and tinnitus due to CN8 involvement
Schwannoma tumor cells are positive for
S-100
When Schwannoma bilateral, think
Neurofibromatosis type 2
Oligodendroglioma appearance on biopsy
Fried-egg
Rosenthal fibers are
Thick eosinophilic process of astrocytes seen in astrocytoma
Homer-Wright rosettes are seen in
Medulloblastoma
Perivascular pseduorosettes are seen in
Ependymoma