Child Neuro Flashcards
Ectoderm
Nervous system
Notochord
layer of mesodermal cells in contact with ectoderm induces formation of the neural plate. Later gives rise to spinal cord!
Neurulation
proliferation/migration of ectodermal cells for fusion of neural plate in a specific pattern forming fusion reaching the neuropore in an anterior to posterior direction–> neural tube formed
Mesodermal cells of notochord
ventral aspect of neural tube 2/2 sonic hedgehog protein
Neurulation process
occurs 3-6 weeks gestation and failure of crucial processes leads to NTD failing to fuse at each site results in specific defects.
Abnormal rostral fusion
anterior neuropore leads to encephalocele or anencephaly
Abnormal caudal fusion
posterior neuropore leads to spina bifida
After neuralation?
3 different segments form the prosencephalon, mesencephalon and rhombencephalon.
Prosencephalon
subsequently forms the telecephalon which gives rise to the cerebral hemispheres and diencephalon forming the hypothalamus/thalamus
Mesencephalon
gives rise to midbrain
Rhombencephalon
brainstem (pons/medulla) and cerebellum
Neural crest cells
form the peripheral nervous system derived from neural tube after it fuses. Also adrenal medulla/melanocytes
Galactosemia
autosomal recessive. 3 enzymes: galactose-1-phosphate uridyltransferase deficiency, galactokinase deficiency
Present with feeding diff, vomiting, jaundice, hepatomegaly, failure to thrive, hypotonia, cataracts d/t glactitiol, developmental delay, ataxia, tremor.
Dx of reducing substance in urine after feeding
Rx lactose/galactose restricted from diet
Pyruvate dehydrogenase deficiency
Oxidative decarboxylation of pyruvate to carbon dioxide and acetyl coenzyme A. X-linked gene. Since brain derives energy primarily from glucose oxidation, neurologic dysfunction manifests ranging from lactic acidosis, ataxia, nystagmus, lethargy, areflexia, hypotonia
Rx ketogenic diet
NF1
normal cognition or mild developmental delay, renal artery stenosis, pheochromocytoma, moyamoya, intracranial aneursyms, macrocephaly
Glut-1 deficiency
transportation past BBB. Manifest with epileptic encephalopathy with infantile onset seizures, developmental delay, microcephaly
Rx ketogenic diet
Phenylketonuria (PKU)
deficiency of phenylalanine hydroxylase converting phenylalanine to tyrosine leading to accumulation–> metabolized to phenylpyruvic acid/phenylacetic acid which gives it a musky smell. Children are blond hair, blue eyes, pale skin given lack of melanin pigment production.
PKU presentation?
appear normal at birth, however if untreated may lead to cognitive delays, microcephaly, seizures, hypotonia
Maple syrup urine disease
autosomal recessive. alpha ketoacid dehydrogenase complex deficiency leading accumulation of branched chain acids (leucine, isoleucine, valine)
Presentation includes progressive encephalopathy, hypotonia, opisthotonus then eventually coma and death
Rx low protient diet
Sacral agenesis
absence of sacrum rather than absence of sacral spinal cord. Associated with insulin-dependent diabetes
Tuberous sclerosis complex
Cardiac rhabdomyomas, most regress over time with manifestations including heart failure due to obstruction or cardiomyopathy,arrhtmias or stroke. Surveillance with periodic echos.
Renal angiomyolipomas benign tumors consisting of vessels, smooth vessel
Lymphangiomyomatosis of chest
Retinal hamartomas
Propionic acidemia
hematologic manifestations such as pancytopenia may occur. Autsomal recessive. Deficiency of propionyl-CoA carboxylase. Appear normal at birth, then develop hypotonia, dehydration, metabolic acidosis , hepatomegaly, seizures, incranial hemoorhage
Rx protein restriction , carnitine, biotin
Lesch-Nyhan disease
X-linked. Deficiency of hypoxanthine gaunine phosphoribiosyltranserase. Purine metabolism. Gene HPRT1, leading to uric acid accumulation. Leads to choreoathetotic movements.
Neiman Pick type A
Spingomyelinase deficiency leading to accumulation of sphingomyelin. Autosomal recessive. Involves CNS and manifests infancy with cherry red spot, hepatosplenomegaly. Histology shows vacolated histiocytes w/lipid accumulation called foam cells.