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.
Neimann Pick type C
defects in intracellular cholestrol circulation accumulating in lysosomes
Metachromatic leukodystrophy
autosomal recesive disorder. Deficiency of lysosomal enzyme arylsulfatas A with accumulation of sulfatide resulting demyelination
MRI shows T2 hyperintense signal changes in periventricular and subcortical white matter, sparing U fibers
Krabbe disease
deficiency of glaactosylceramidase
Tay Sachs disease
deiciency of hexosaminidase
Hydromyelia vs syringomyelia
fluid filled cavity vs central canal diltation
Sialdosis
myoclonic epilepsy. Lysosomal storage disorders. Coarse facial features, skeletal abnormalities, psychomotor retardation. Deficiency of lysosomal alpha n-acetyl neuraminidase. Type I - cherry red spot develops in adulthood. Type II child form, severe neuro deficits
Jouberts syndrome
autosomal recessive. Molar tooth sign which results from cerebellar vermis hypoplasia with 4th ventricle enlargement, abnormal superior cerebellar peduncles.
Ataxia, oculomotor apraxia, resp diff,
Fabrys
X linked disorder deficiency of alpha-galactosidase resulting in accumulation of ceramide trihexoside.
small fiber neuropathy, autonomic dysfunction, renal failure, cardiomyopathy. Lysosomal storage of birefringent lipids on EM.
GM 1 gangliosidosis
B-galactosidase deficiency
Neuronal ceroid lipofuscinosis
autosomal recessive disorders characterized by progressive psychomotor retardation, seizures, blindness.
Congential aqueductal stenosis
narrowing of cerebral aqueduct that connects the third and fourth ventricle, disorder of neurulation
Zellwegers syndrome
peroxisomal disodrer in which white matter is involved, Very long chain fatty acids. Pachygyria or polymicrogyria
Fabry disease
X linked. Deficeincy of lysosomal enzyme alpha galactosidase. Purplish aniogkeratomas, small fiber neuropathy, stroke, multiple organ failure
Hereditary hemorrhagic telangiectasia
autosomal dominant. Recurrent epstaxis. Mutiple AVMs or cerebral embolisms
Septo-optic dysplasia
absence of septum pellucidum, optic nerve/chiasm, corpus callosum. Associated with lobar holopresechephaly.
Adrenoleukodystrophy
X-linked. ABCD1 gene mutation. Impaired transport of very long chain fatty acids into peroxisomes, preventing beta-oxidation with subsequent accumulation. Presents with bulbar sxs, spasticity, adrenal insufficiency. senosory neuropathy, elevated ACTH
Arrhinencephaly
agenesis of olfactory bulb/tract
Leighs syndrome
subacute encephalomyelopathy. Mitochondrial disorder. myoclonic jerks. Elevated CSF/blood lactate levels. MRI brain b/l symmetric hyperintense T2 signals of brainstem/basal ganglia
Kearns-Sayre syndrome
Mitochondrial DNA deletion. Triad of progressive external ophthalmoplegia, onset before 20, short stature, cerebellar ataxia, heart block
Congenital disorders of glycosylation (CDG)
Autosomal recessive. Affect multiple organs. Developmental delay/dysmorphic features. Abnormal processing of glycans of glycoproteins. Inverted nipples, fat pads in buttocks is distinctive.
Dx carbohydrate-deficient transferrin in serum/CSF