MICROCEPHALYMICROCEPHALY

DefinitionDefinition:: Small head in which head Small head in which head

circumference is below the 3rd circumference is below the 3rd centile for age and sexcentile for age and sex..

CausesCauses:: 1- 1- Primary (Genetic)Primary (Genetic):: Familial (usually AR, may be AD Familial (usually AR, may be AD

or sporadic).or sporadic). Chromosomal: Chromosomal: Trisomies e.g. 21, 18, 13.Trisomies e.g. 21, 18, 13. Deletions e.g. Cri-du chat (del. Deletions e.g. Cri-du chat (del.

Ch. 5).Ch. 5).

2- 2- Secondary (non-Genetic)Secondary (non-Genetic):: Intrauterine infection: (TORSCH)Intrauterine infection: (TORSCH) Intrauterine irradiation: (esp. 1st and Intrauterine irradiation: (esp. 1st and

2nd trimester).2nd trimester). Intrauterine hypoxia: (Hypoxic-Intrauterine hypoxia: (Hypoxic-

ischaemic encephalopathy).ischaemic encephalopathy). Intrauterine drug exposure: (e.g. Intrauterine drug exposure: (e.g.

hydantoin or alcohol).hydantoin or alcohol). Meningitis / encephalitis.Meningitis / encephalitis. Metabolic: (Maternal DM, Maternal Metabolic: (Maternal DM, Maternal

phenylketonuria). phenylketonuria).

DiagnosisDiagnosis:: HistoryHistory: : of drugs, irradiationof drugs, irradiation, ,

………….. Family historyFamily history.. ExaminationExamination Investigations for the causeInvestigations for the cause..

CRANIO SYNOSTOSISCRANIO SYNOSTOSIS

Def.Def.:: Early fusion of one or more of skull Early fusion of one or more of skull

sutures. If multiple sutures are sutures. If multiple sutures are involved small sized head may result.involved small sized head may result.

N.B.N.B. small sized head may be due small sized head may be due to:to:

True microcephaly True microcephaly small brain size. small brain size. Craniosynostosis Craniosynostosis early fusion of early fusion of

skull sutures.skull sutures.

AetiologyAetiology:: 1- 1- CongenitalCongenital: Isolated or : Isolated or

associated with other syndromes associated with other syndromes e.g. Carpanter e.g. Carpanter

syndrome, Crouzon syndrome, Crouzon syndrome, ………... syndrome, ………...

2- 2- AcquiredAcquired: (uncommon) e.g. : (uncommon) e.g. Hypercalcaemia.Hypercalcaemia.

C/PC/P:: 1- 1- Abnormal shape of the skullAbnormal shape of the skull: :

(according to the closed suture) may (according to the closed suture) may be:be:

Elongated head Elongated head Scaphocephaly. Scaphocephaly. Short head Short head Brachycephaly. Brachycephaly. Conical shaped headConical shaped head Acrocephaly. Acrocephaly. Triangular head Triangular head Trigonocephaly. Trigonocephaly.

2- 2- Skull examinationSkull examination:: Palpable ridge corresponding to Palpable ridge corresponding to

the affected suture.the affected suture. Manifestations of Manifestations of ICT if multiple ICT if multiple

sutures are involved.sutures are involved. May be small sized head.May be small sized head.

InvestigationsInvestigations:: 1- 1- Skull X-raySkull X-ray: : Fusion of sutures.Fusion of sutures. May be May be ICT (Silver beaten ICT (Silver beaten

appearance and wide sella turcica).appearance and wide sella turcica). 2- 2- CT brainCT brain:: May show hydrocephalic changes May show hydrocephalic changes

(relative (relative

TreatmentTreatment:: Surgical separation of skull sutures Surgical separation of skull sutures

are indicated in:are indicated in: Cases with hydrocephalus.Cases with hydrocephalus. Cases with progressively Cases with progressively ICT. ICT. Cosmotic reasons.Cosmotic reasons.

MENTAL RETARDATIONMENTAL RETARDATION

Def.Def.:: Handicapping disorder with Handicapping disorder with

age of onset below 18 age of onset below 18 years chch by subnormal years chch by subnormal I.Q. (< 70). I.Q. (< 70).

CausesCauses:: I- I- SubculturalSubcultural: Children living in low-: Children living in low-

socioeconomic standard, with poverty & socioeconomic standard, with poverty & neglect.neglect.

II- II- Genetic causesGenetic causes:: Brain anomalies: e.g. cong. Brain anomalies: e.g. cong.

hydrocephalus, familial microcephaly, ….hydrocephalus, familial microcephaly, …. Chromosomal anomalies: e.g. Trisomies, Chromosomal anomalies: e.g. Trisomies,

deletions, ….deletions, …. Degenerative brain diseases: e.g. Degenerative brain diseases: e.g.

Demyelinating diseases.Demyelinating diseases. Errors of metabolism: e.g. Errors of metabolism: e.g.

aminoacidopathies, lipidosis, ….aminoacidopathies, lipidosis, ….

III- III- Non-genetic causesNon-genetic causes:: Pre natalPre natal:: Congenital infections (TORSCH).Congenital infections (TORSCH). Congenital brain malformations.Congenital brain malformations. Fetal irradiation or drugs.Fetal irradiation or drugs. NatalNatal:: Birth asphyxia.Birth asphyxia. Birth trauma “ICH”.Birth trauma “ICH”. Hypoglycaemia.Hypoglycaemia.

PostPost natalnatal:: CNS infection (post-CNS infection (post-

meningitis, post-encephalitis).meningitis, post-encephalitis). Kernicterus.Kernicterus. Cerebro-vascular accidents.Cerebro-vascular accidents. Severe hypoglycaemia or Severe hypoglycaemia or

hypernatraemia hypernatraemia

ManifestationsManifestations:: Delayed Delayed Social Social development development In In

infancy.infancy. Delayed Delayed SpeechSpeech In early childhood. In early childhood. SchoolSchool underachievement underachievement In late In late

childhood.childhood. InvestigationsInvestigations:: For the cause e.g. chromosomal analysis, For the cause e.g. chromosomal analysis,

CT brain, metabolic screen, …;However CT brain, metabolic screen, …;However with extensive investigations a specific with extensive investigations a specific cause is found only in 25% of casescause is found only in 25% of cases

ManagementManagement:: I- I- PreventionPrevention: : Proper prenatal- natal and post Proper prenatal- natal and post

natal care.natal care. Vaccination against rubella for Vaccination against rubella for

females (not during pregnancy).females (not during pregnancy). Neonatal screening to identify Neonatal screening to identify

preventable causes of MR (e.g. preventable causes of MR (e.g. phenylketonuria).phenylketonuria).

TTT of neonatal jaundice, TTT of neonatal jaundice, hypoglycaemia, ….hypoglycaemia, ….

II- II- TreatmentTreatment:: No specific ttt, but rehabilitation of the No specific ttt, but rehabilitation of the

child is depending on degree of MR.child is depending on degree of MR. Mild MR (IQ 50-70) Mild MR (IQ 50-70) Educable (may Educable (may

need special classes)need special classes) Moderate MR (IQ 35-50) Moderate MR (IQ 35-50) Trainable Trainable

(they are trained to care for themselves) (they are trained to care for themselves) Severe MR (IQ 20-35) Severe MR (IQ 20-35) Trainable. Trainable. Profound MR (IQ 0-20) Profound MR (IQ 0-20) Non trainable Non trainable

(so, they need full time nursing care).(so, they need full time nursing care).