12-2 Pedi Neuro II Flashcards
floppy baby ddx
upper motor neuron vs. lower motor neuron
- spinal muscular atrophy
- congenital myasthenia gravis
- congenital myotonic dystrophy
- congenital muscular dystrophy
- congenital (peripheral) neuropathy
Think through from ant horn cell —> axon —> NMJ —> muscle
1a. Werdnig-Hoffman disease (Spinal Muscle Atrophy Type I) —Presentation —Genetics —Dx —Prognosis
PRESENTATION: present w/ symmetric mm. weakness (prox>distal), atrophy (hard to see w/ baby fat), absent DTR, tongue fasciculations, tremor in the first 6 mos of life
GENETICS: autosomal recessive mutation of SMN1 (survival motor neuron); SMN2 is expressed to make up for this lack, but not enough made to make up for it; amt of SMN2 you make dictates severity of phenotype
—Type 1 has only one copy of SMN2 and no SMN1
DX: EMG shows features of denervation (problem is w/ nerve NOT muscle), muscle bx shows atrophic fibers next to hypertrophied fibers trying to compensate
PROG: death w/in first 2 years =(
1b. Type II & III SMA
both survive long-term
—Type II (intermediate): sit; cannot stand or walk
—Type III (Kugelberg-Welander): proximal weakness after 18 months; walk, do not run; has 2 copies of SMN2 but no SMN1
2. Charcot-Marie Tooth —Presentation —Genetics —Dx —Tx —Prognosis
**most commonly inherited peripheral neuropathy
—PRESENT: Progressive DISTAL weakness, foot drop/Steppage gait, Mild sensory loss, Depressed DTRs, heelcord contractures, high arches with hammer toes, Inverted champagne bottle legs (b/c prox muscles spared
—GENETICS: usually AD inher—parents often have high arches; mutation in PMP (periph myeline prot) a protein that keeps myelin tightly applied to axons
—DX: “DNA, family history; nerve biopsy shows onion-skinning from relapsing myelination/demyelination
—TX: Orthopedic support, bracing
—PROG: normal lifespan; severe forms exist
- Congenital Myasthenia Gravis
—Presentation ONLY
—PRESENT: fine for first few wks, then develop nl MG sx
4. Duchenne/Becker's Muscular Dystrophy —Presentation —Genetics —Dx —Tx —Prognosis
—PRESENT: Gower’s sign to stand, pseudohypertrophic calves, massively high CK
—GENETICS: mutation in dystrophin Duchenne (quantitative) Becker’s (qualitative)
—DX: biopsy shows atrophied muscle fibers being replaced by fat and fibrosis; no dystrophin when stained
—TX: eteplirsen (oligo which triggers excision of exon 51 during pre-mRNA splicing–shifts frame back to correct one in certain frame-shift cases of DMD)
- Congenital Muscular Dystrophy
—Presentation
—Dx
—Etiology
PRESENT: w/ weak muscle from the start (vs. delayed onset in Becker’s/Duchenne’s)
—Varied presentation: hypotonia, feeding problems, mild distal contractures common, CK markedly elevated, esp early on, sit unsupported by 3 years, but rarely walk, respiratory failure, feeding problems, failure to thrive
DX: MRI shows white matter changes (resemble a leukodystrophy); ~5% also have abnl cortex,; assoc’d w/ MR and 30% have epilepsy
ETIOLOGY: due to mutation in Merosin, a protein that anchors the dystrophin/dystrophin-associated-proteins into the ECM
Why are there neurocutaneous d/o?
b/c both the skin and NS came from ectoderm back in the day
- Neurofibromatosis (NF) I
—Presentation
—Diagnostic Criteria
—Complications
multiple types of NF, most well recognized types I and II (“peripheral” and “central”)
NF-I: multiple tumors in CNS and PNS, cutaneous pigmentation, vascular and visceral lesions, increased risk malignancy; 85% of cases of NF
PRESENTATION:
Short stature, macrocephaly, scoliosis
- NF II
-no skin s/sx
Far less common; also AD as NF-I
8. Tuberous Sclerosis —Presentation —Genetics —Complications —Tx
PRESENTATION:
Neuro: infantile spasms & ASD
Skin: hypopigmented macules “ash-leaf spots”-90%, peau d’orange (Shagreen patch), fibrous plaques, periungual fibromas, facial angiofibromas (with age)
9. Sturge-Weber Syndrome —Presentation —Genetics —Dx —Tx —Prognosis
PRESENT:
—intractable szs (75%)
—Hemiplegia, progressive, hemianopia
—MR (40%)
—Port Wine Stain in distrib of V1 ipsilateral to
—Venous angioma of leptomeninges
—cortical calcifications, brain atrophy(hemispheric)
—GENETICS: always spontaneous mutation, never familial
—DX: MRI with contrast good in newborn, as calcifications may not be present (CT)
—TX: hemispherectomy early on
—Prognosis
What class of tumors are the most common malignancies in children?
brain tumors (Pilocytic astrocytoma most common of these)
what are the three components of Parinaud syndrome?
- Paralysis of upward gaze
- Pseudo-Argyll Robertson pupils
- Convergence-Retraction nystagmus
—”results from injury, either direct or compressive, to the dorsal midbrain. Specifically, compression or ischemic damage of the mesencephalic tectum, including the SUPERIOR COLLICULUS adjacent oculomotor (origin of cranial nerve III) and Edinger-Westphal nuclei, causing dysfunction to the motor function of the eye.”
- Medulloblastoma
Super common: 20% of all childhood tumors
PATH:
—Arise vermis, fill IVth, infiltrate floor, may seed the subarachnoid space
—small round blue cells, pseudorosettes
—elsewhere = “PNET”; mets to bones and LNs
TX: surgery followed by rad; chemo is not effective
