CC May 2016 Microcephaly

echoecho's version from 2016-07-04 16:30


Question Answer
Define microcephaly?a head circumference (HC) that is 2 standard deviations (SD) or more BELOW the mean for age and gender
List the categories of microcephaly?1) mild or borderline microcephaly = HCs 2-3 SD below the mean 2) severe microcephaly = HCs > 3 SD below the mean
List 4 additional classifications?1) timing of onset = primary or congenital (HC is small at birth) vs. secondary or acquired (HC is normal at birth but then growth slows) 2) relationship to other growth parameters = symmetric (proportional) or asymmetric (disproportional) 3) etiology = genetic vs. environmental 4) association with other anomalies = syndromic or isolated
When evaluating a child for microcephaly, it is important to take an accurate measurement of what?HC (head circumference)
What type of tape measure should be used and what part of the head should be measured?1) tape measure that does not stretch 2) encircle head at the MOST prominent part of the occiput and 1-2 cm ABBOVE the glabella anteriorly
The CDC recommends using the curves from the _____ for children up to age 2 years, tehn switching to the _____curves for older children?1) WHO 2) CDC
It is important to identify what, if possible in children with confirmed microcephaly?etiology
In a recent retrospective study of 680 children with microcephaly (mean age at dx 7-8 months), a cause was found in ____% of cases?59
List the etiologies of microcephaly?1) Genetic (isolated or syndromic) 2) Acquired (disruptive injuries or infectious; or teratogens or deprivation)
List the primary and secondary causes of genetic (isolated) etiology?1) primary = autosomal dominant and autosomal recessive microcephaly, x-linked microcephaly 2) secondary = inborn erros of metabolism (mitochondrial disorder)
List the primary and secondary causes of genetic (syndromic) etiology?1)primary = Trisomies 13, 18, and 21; Cornelia De Lange syndrome; Smith-Lemil-Opitz syndrome 2) Secondary = Rett syndrome; ataxia-telangiectasia
List the primary and secondary causes of acquired (disruptive injuries) etiology?1) primary = death of monozygous twin, ischemic or hemorrhagic stroke 2) secondary = traumatic birth injury, hypoxic-ischemia, hemorrhagic and ischemic stroke
List the primary and secondary causes of acquired (infectious) etiology?1) primary = TORCHES (toxoplasmosis, rubella, cytomegalovirus, herpes simplex, syphilis), HIV, Zika virus 2) secondary: meningitis, encephalitis
List the primary and secondary causes of acquired (teratogens) etiology?1) primary = alcohol, phenytoin, radiation, poorly-controlled maternal diabetes 2) secondary = lead poisoning, chronic renal failure
List the primary and secondary causes of acquired (deprivation) etiology?1) primary = maternal - hypothyoridism, malnutrition, folate deficiency, placental insufficiency 2) secondary = hypothyroidism, anemia, congenital heart disease, malnutrition
Is microencephaly a sign or a diagnosis?it is a sign and NOT a diagnosis
*** Initial evaluation for all children includes?physical exam to identify other possible abnormalities and assessment of the family for any specific diseases or syndromes
*** What should be done for infants with proportionate microcephaly who havve no neurologic signs/ symptoms OR family hx of childhood neurologic dse should be?observed
*** What testing should be considered if there is worsening of the microcephaly or development of neurologic signs/symptoms? MRI, metabolic or genetic testing
*** Infants with disproportionate microcephaly should have an?MRI
*** If physical findings suggest a certain dse or syndrome, what should be done for that condition?specific testing
When evaluating acquired microcephaly, the presence of what or neurological signs and symptoms would warrant an MRI?severe microcephaly
What should be considered for all children who have an MRI showing normal or nonspecific findings?further testing (genetic, metabolic, infectious, endocrine) should be considered
*** SUMMARY = Microcephaly can be what 2 categories?1) primary (congenital) 2) secondary (acquired)
*** SUMMARY = Severe microcephaly or neurologic s/s should prompt what imaging of the brain?MRI
*** SUMMARY = List etiologies of microcephaly?1) genetic defects 2) infectious 3) exposure to teratogens 4) disruptive injuries 5) deprivation states