PNS, CNS Flashcards
MC inherited peripheral neuropathy
Charcot Marie Tooth
MC type: CMT1, 2nd decade, distal demyelinating
CMT2A: early, childhood, axonal neuropathy
MC chronic acquired peripheral neuropathy
Chronic inflammatory demyelinating poly (radiculo) neuropathy
symmetric mixed sensorimotor polyneuropathy >/2 mos
recurrent demyelination and remyelination with Schwann cell prolif
acute symmetric ascending demyelinating polyradiculoneuropathy
T cell mediated
ascending paralysis and areflexia
Guillan Barre syndrome
CSF: Albuminocytologic dissociation
MCC of PN
DM
Neuromuscular disease
+ weakness with exertion
EOM muscle group
Myasthenia gravis
HS type II
Assoc: Thymoma, thymic hyperplasia
post synaptic ACh receptor autoantibodies
Neuromuscular disease
- muscle weakness upon exertion
Extremities
assoc: neuroendocrine Ca of the lungs
Lambert eaton myasthenic syndrome (LEMS)
autoantibodies against Presynaptic Calcium channels
MC inflammatory myopathy
Juvenile - Dermatomyositis
Adult - usually paraneoplastic
Skin changes seen in Dermatomyositis
Heliotrophe rash - periorbital lilac discoloration
Gottron papules - dusky rash patches over knuckles, knees and elbows
pattern of atrophy: perifascicular
antibodies in Dermatomyositis for gottron and heliotrope rash
anti-Mi2
P155/P140 - paraneoplastic, juvenile form
total absence of Dystrophin X on chromosome
pelvic girdle weakness
pseudohypertrophy of lower leg muscles
Gower sign
- Dystrophin IHC
Duchene muscular dystrophy
Becker - milder, late onset, reduced dystrophin on IHC
Cell dense areas with spindle cells arranged in fascicles with nuclear palisading
Antoni A
Verocay bodies - Cell-free areas due to nuclear palisading
Cell poor areas with prominent MYXOID stroma
Antoni B
mutation: NF2 (Merlin) (Ch22) inactivation
Biphasic appearance: Antoni A and Antoni B
Verocay Bodies
+ S100
Schwannoma
+S100 - positive in neural crest cell derived cells (other: melanocytes)
mutation: NF1 (Ch17) inactivation
+ S100, spindle cells, + CD34
plexiform: Bag of worms appearance
Neurifibroma
“shredded carrots appearance”
Components of neurofibromatosis
Bilateral 8th nerve
Schwannoma
multiple meningioma
ependymoma
Most important pathologic marker of CNS injury
Gliosis
acute neuronal injury: Red neuron
subacute and chronic neuronal injury: Degeneration
Herniating part in Subfalcine
Cingulate
herniation thru under flax cerebri
compressed: anterior cerebral artery
compressed structure in Transtentorial herniation
CN III
Posterior Cerebral artery
CL cerebral peduncle
herniating part: medial aspect of temporal lobe
herniating thru: tentorium cerebelli
linear or flame-shaped lesion hemorrhagic lesion in brainstem and pons
Duret hemorrhages
tonsillar herniate through
Compressed sturcture
Foramen magnum
herniating part: cerebellar tonsils\
Compressed: Brainstem – cardio and respi depression
MC CNS malformation
Neural Tube defects
RF: folate deficiency
MC neural tube defect
Spinal Dysraphism/Spina bifida
extension of the spinal cord and meninges through the vertebral column defect
Myelomeningocele
meningocele: meninges only
extrusion of malformed brain tissue thru a midline cranial defects
Encephalocele
Loc: Occiput
Incomplete separation of the cerebral hemispheres across the midline
Holoprosencephaly
assoc. Trisomy 13
Cyclopia, Arrhinencephaly - absence of olfactory cranial nerves
Enlarged posterior fossa (absence of hypoplasia of cerebellar vermis)
Cystic dilatation of the 4th ventricle
Dandy-walker malformation
MC site of contusion
Frontal lobe
Small cavitary infarcts assoc with hypertension
Lacunar Infarcts
Common site: Putamen
Neurons most SENSITIVE to ischemia
Pyramidal layer of hippocampus
Pyramidal cells of cerebral cortex
Cerebellar Purkinje cells
Infarcts in areas that lie at borders of arterial territories
Borderzone (watershed) Infarcts
MC area: ACA-MCA border zone
MC type of intracranial aneurysm
Saccular aneurysm
MC location: ACA- ACoA junction
Most clinically significant vascular malformation
Arteriovenous Malformation
10-30yrs, Males
MC site: Posterior branches of MCA
Large BV separated by gliotic tissue
+ shunting
Distended loosely organized back to back vascular channels without intervening brain tissue
Cavernous Malformation
MC site: Cerebellum
- shunting
MCC of Acute aseptic Meningitis
Enterovirus 80%
Viral: Lymphocytic
Chemical - neutrophil
N sugar, Inc Protein, - culture
MC agents in Brain Abscess
Staphylococci
Strepcocci
MC Demyelinating disorder
Multiple sclerosis
AI demyelinating disorder
Cell mediated CD4+
Unilateral involvement of the optic nerve (optic neuritis)
Multiple Sclerosis
CSF: moderate pleocytosis, mildly elevated protein, IgG, Oligoclonal IgG bands
MC prion disease
Creutzfeldt-Jakob disease
Progressive dementia, Startle myoclonus, 7th decade, Kuru plaques
Prion - rapidly progressive neurodegenerative disease
MCC of dementia in older adults
Alzheimer disease
AB (forms plaques and tangles), Tau aggregates (stress response)
Chromosome 21, 19 (ApoE)
terminal event: pneumonia
Parkinson TRIAD
Tremor
Rigidity
Bradykinesia
Loss of Dopaminergic neurons in Substantia Nigra
Dementia with Lewy Bodies
Pallor of substantia nigra and locus coeruleus
Parkinson Disease
Dx HM: Lewy body (a-synuclein)
Loss of striatal neurons that dampen motor output
mutation in Glucocerebrosidase
CAG trinucleotide repeat
Cortical atrophy
Huntingtin aggregates
Huntington Disease
AR, progressive ataxia, cardiomyopathy
GAA trinucleotide repeat expansion (Ch9)
Friedreich Ataxia
Weakness and atrophy
SOD1 (Ch21) mutation
Bunina bodies: PAS+
Corticospinal tract degeneration
Amytrophic lateral sclerosis
- loss of Upper motor neuron and Lower motor Neuron
most susceptible neuron in Hypoglycemia state
Dorsomedial nucleus of the thalamus
MC primary tumor
Gliomas: Astrocytoma, Oligodendroglioma, Ependymoma
High grade infiltrating astrocytoma Necrosis: Palisading
Microvascular prolif: Glomeruloid
Glioblastoma
Necrosis: Palisading
Microvascular prolif: Glomeruloid
WHO IV/IV
Glioblastoma
Necrosis: Palisading
Microvascular prolif: Glomeruloid
WHO I/IV
Pilocytic astrocytoma
localized low grade glioma – found in children
mural nodule
Rosenthal fibers
WHO II/IV
Fried egg appearance of cells
Oligoendroglioma
mutation in IDH1 and concurrent 1p19q codeletion
Chicken wire vascular network
Calcifications
Perineuronal Satellitosis in cortical tumors
WHO II/IV
Perivascular rossette
Ependymoma
first 2 decades of life: at 4th ventricle
adult: spinal cord
MC embryonal neoplasm
Medulloblastoa WHO IV/IV
afflicts children
Homer-wright rosette
small round blue cells inc mitosis
MC CNS neoplasm in Immnocompromised individuals
primary CNS Lymphoma
MC subtype: DLBCL
in immunocompromised: +EBV
NF2 deletion Ch22q12
Dural tail
I/IV: Meningothelial, Psammoma bodies
Menigioma
Cytogenic Origin of Meningioma
Meningothelial cells of arachnoid
AD, loss of function TSC1 (Ch9) and TSC2 (Ch16)
Hamartomatous cortical tubers
CT: Melted candled
Tuberous Sclerosis Complex
