University:
Swansea University
Course:
PM-139 | Human Physiology 1
Academic year:

2023
Views:

9

Pages:

5
Author:

Amal J.

MICROCEPHALYmicro cephaly is a medial conditionin which the circumference of thehead is smaller than normal nonethan two standard division smallerthen average for the person age csec)because the brain has not developedproperly for Jackas stopping growingmicrocephaly can be present atbirth or. it may develop in theisfirst tear year of life.normal head circumference atbirthrange from 132 - 37) am.thst?Rate of growth of headincircumtance (HC).2 cm/month,st three month of lifeIcm / month4-6 month of ageO. 5 cm 1month6-12 months of age.47 in at I year of age49 an at 2y ears of age , H97Indi. Incidence of moderate to severemental retardation:eNtThe severity of mentalretardation has been rebted to theseverity of the microephaly.HC from:ifrast below the ageis 33% risk offedeveloping MR.HO >33D incidence is 62%the reflects brain volume,a small skill reflects a smallrprainHow ever, some childrenwith microcephaly may have of herbirth defects, such as short staltwietacial abnormalities T brain abnormalor seizures or develop mental-iitydelay.classification:we can classity microcophalysimply according toTime of onset C congenital(or)It's pathogenisis.post nater). > genitic) cor) (2 very -environmental acquired).microcephaly can be isolatedwith so other obvious abnormalities,or it may be associated with otheranomailes. which is termedSyndronic.pathogenisis:pathogenisis. is very heterogenouswhich can present a challenge forthe clinical attempting to determinewheather environment or geneticfactor are causative.These factor may actprenately , porinatelly or postnatallyto inhibit the brain growth.same possible factors:small brain & poorlygrowing skell.An abnormal neuronalmigration during fetal development.us to archi tectural dearrangement. what are the causes of microcophalyprimary micro cephaly(genetiprenatel causes: :chromosomal abnormalies :Down syndrome (21 trisomy)Edward syndrome (18trisomy)patau syndrome (13 trisomy)malformation:Lissen cephalyDelange syndrome.Hereditory condition:Autosomal recessive(familiar)Autosomal dominant2) postnatel causes :malformation syndrome :secondary microcephaly (acquired)prenatal causes :I intrauterine TORCH in fectionFetal alchol syndromemeternal phony cketauria. bypostnatel causes :Puri natel asphysnia.peri natel acquired herpes,si mplon encephalitis) menigitis.Head injuryEndocrine anomalies.congenital CNS anomalies:Agenesis of the cerepellar vormisAgenesis of the Corpus collosum.Encephalo cole.other causes:HyporthermiaRadiationmalnutritionDrugs.Isolated micro cephaly:"micro cephaly vera "or truemicro ceptuly has been defined asgenetic condition in which the brain isabnormally small because of reducenumber of newsons but is keepingnormal cystral pattern and beinguncomplicated by other anomalies