MICROCEPHALY

 Definition:  Definition:  Small head in which head circumference is below the 3rd centile for age and sex.  Small head in which head circumference is below the 3rd centile for age and sex.

 Causes:  Causes: 1- Primary (Genetic): 1- Primary (Genetic):  Familial (usually AR, may be AD or sporadic).  Familial (usually AR, may be AD or sporadic).  Chromosomal:  Chromosomal:  Trisomies e.g. 21, 18, 13.  Trisomies e.g. 21, 18, 13.  Deletions e.g. Cri-du chat (del. Ch. 5).  Deletions e.g. Cri-du chat (del. Ch. 5).

2- Secondary (non-Genetic): 2- Secondary (non-Genetic):  Intrauterine infection: (TORSCH)  Intrauterine infection: (TORSCH)  Intrauterine irradiation: (esp. 1st and 2nd trimester).  Intrauterine irradiation: (esp. 1st and 2nd trimester).  Intrauterine hypoxia: (Hypoxic-ischaemic encephalopathy).  Intrauterine hypoxia: (Hypoxic-ischaemic encephalopathy).  Intrauterine drug exposure: (e.g. hydantoin or alcohol).  Intrauterine drug exposure: (e.g. hydantoin or alcohol).  Meningitis / encephalitis.  Meningitis / encephalitis.  Metabolic: (Maternal DM, Maternal phenylketonuria).  Metabolic: (Maternal DM, Maternal phenylketonuria).

 Diagnosis:  Diagnosis:  History:  of drugs, irradiation, …….  Family history.  History:  of drugs, irradiation, …….  Family history.  Examination  Examination  Investigations for the cause.  Investigations for the cause.

CRANIO SYNOSTOSIS

 Def.:  Def.: Early fusion of one or more of skull sutures. If multiple sutures are involved small sized head may result. Early fusion of one or more of skull sutures. If multiple sutures are involved small sized head may result. N.B.  small sized head may be due to: N.B.  small sized head may be due to:  True microcephaly  small brain size.  True microcephaly  small brain size.  Craniosynostosis  early fusion of skull sutures.  Craniosynostosis  early fusion of skull sutures.

 Aetiology:  Aetiology: 1- Congenital: Isolated or associated with other syndromes e.g. Carpanter 1- Congenital: Isolated or associated with other syndromes e.g. Carpanter syndrome, Crouzon syndrome, ………... syndrome, Crouzon syndrome, ……… Acquired: (uncommon) e.g. Hypercalcaemia. 2- Acquired: (uncommon) e.g. Hypercalcaemia.

 C/P:  C/P: 1- Abnormal shape of the skull: (according to the closed suture) may be: 1- Abnormal shape of the skull: (according to the closed suture) may be:  Elongated head  Scaphocephaly.  Elongated head  Scaphocephaly.  Short head  Brachycephaly.  Short head  Brachycephaly.  Conical shaped head  Acrocephaly.  Conical shaped head  Acrocephaly.  Triangular head  Trigonocephaly.  Triangular head  Trigonocephaly.

2- Skull examination: 2- Skull examination:  Palpable ridge corresponding to the affected suture.  Palpable ridge corresponding to the affected suture.  Manifestations of  ICT if multiple sutures are involved.  Manifestations of  ICT if multiple sutures are involved.  May be small sized head.  May be small sized head.

 Investigations:  Investigations: 1- Skull X-ray: 1- Skull X-ray:  Fusion of sutures.  Fusion of sutures.  May be  ICT (Silver beaten appearance and wide sella turcica).  May be  ICT (Silver beaten appearance and wide sella turcica). 2- CT brain: 2- CT brain:  May show hydrocephalic changes (relative  May show hydrocephalic changes (relative

 Treatment:  Treatment: Surgical separation of skull sutures are indicated in: Surgical separation of skull sutures are indicated in:  Cases with hydrocephalus.  Cases with hydrocephalus.  Cases with progressively  ICT.  Cases with progressively  ICT.  Cosmotic reasons.  Cosmotic reasons.

MENTAL RETARDATION

Def.: Def.: Handicapping disorder with age of onset below 18 years chch by subnormal I.Q. (< 70). Handicapping disorder with age of onset below 18 years chch by subnormal I.Q. (< 70).

Causes: Causes: I- Subcultural: Children living in low- socioeconomic standard, with poverty & neglect. I- Subcultural: Children living in low- socioeconomic standard, with poverty & neglect. II- Genetic causes: II- Genetic causes:  Brain anomalies: e.g. cong. hydrocephalus, familial microcephaly, ….  Brain anomalies: e.g. cong. hydrocephalus, familial microcephaly, ….  Chromosomal anomalies: e.g. Trisomies, deletions, ….  Chromosomal anomalies: e.g. Trisomies, deletions, ….  Degenerative brain diseases: e.g. Demyelinating diseases.  Degenerative brain diseases: e.g. Demyelinating diseases.  Errors of metabolism: e.g. aminoacidopathies, lipidosis, ….  Errors of metabolism: e.g. aminoacidopathies, lipidosis, ….

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

 Post natal:  Post natal:  CNS infection (post-meningitis, post-encephalitis).  CNS infection (post-meningitis, post-encephalitis).  Kernicterus.  Kernicterus.  Cerebro-vascular accidents.  Cerebro-vascular accidents.  Severe hypoglycaemia or hypernatraemia  Severe hypoglycaemia or hypernatraemia

 Manifestations:  Manifestations:  Delayed Social development  In infancy.  Delayed Social development  In infancy.  Delayed Speech  In early childhood.  Delayed Speech  In early childhood.  School underachievement  In late childhood.  School underachievement  In late childhood.  Investigations:  Investigations: For the cause e.g. chromosomal analysis, CT brain, metabolic screen, … ;However with extensive investigations a specific cause is found only in 25% of cases For the cause e.g. chromosomal analysis, CT brain, metabolic screen, … ;However with extensive investigations a specific cause is found only in 25% of cases

 Management:  Management: I- Prevention: I- Prevention:  Proper prenatal- natal and post natal care.  Proper prenatal- natal and post natal care.  Vaccination against rubella for females (not during pregnancy).  Vaccination against rubella for females (not during pregnancy).  Neonatal screening to identify preventable causes of MR (e.g. phenylketonuria).  Neonatal screening to identify preventable causes of MR (e.g. phenylketonuria).  TTT of neonatal jaundice, hypoglycaemia, ….  TTT of neonatal jaundice, hypoglycaemia, ….

II- Treatment: II- Treatment: No specific ttt, but rehabilitation of the child is depending on degree of MR. No specific ttt, but rehabilitation of the child is depending on degree of MR.  Mild MR (IQ 50-70)  Educable (may need special classes)  Mild MR (IQ 50-70)  Educable (may need special classes)  Moderate MR (IQ 35-50)  Trainable (they are trained to care for themselves)  Moderate MR (IQ 35-50)  Trainable (they are trained to care for themselves)  Severe MR (IQ 20-35)   Trainable.  Severe MR (IQ 20-35)   Trainable.  Profound MR (IQ 0-20)  Non trainable (so, they need full time nursing care).  Profound MR (IQ 0-20)  Non trainable (so, they need full time nursing care).