Annormalities of head size and shape

Annormalities of Head Size and Shape

1. Abnormalities of Head Size and Shape Mr.Riyaz Khan Aug-2012 Batch VI th Semster Department of Pediatrics Nepalgunj Medical College- Kohalpur

2. MACROCEPHALY Definition : Head circumference ( occipito frontal ) > 2 standard deviation(SD) above the mean for age and sex.

3. 1 SD = 1.25 CM Macrocephaly > 2 SD i.e. 2.5 cm Microcephaly < 3 SD i.e 3.75 cm Take 50 centile as base line

4. 1. Megalencephaly -Benign Familial - Neurocutaneous syndromes : Neurofibromatosis, tuberous sclerosis -Fragile X syndrome - Leucodystrophies & Lysosomal storage disease 2. Increased Cerebrospinal fluid -Hydrocephalous -Benign enlargement of subarachnoid space 3. Enlarged Vascular compartment - Arteriovenous malformation -Subdural, epidural, subarachnoid or intraventricular hemorrhage Causes of Macrocephaly

5. cont…. 4. Increase in bony compartment Bone disease : Achondroplasia , osteogenesis imperfecta , osteopetrosis Bone marrow expansion : Thalassemia major 5. Miscellaneous causes Intracranial mass lesions : Cyst, abscess or tumor Raised intracranial pressure : Idiopathic pseudotumor cerebri , lead poisoning, galactosemia

6. Head Circumference Normal head circumference growth velocity: Birth-35cm 0-3 months : +2 cm/month(41cm) 3-6 months :+ 1 cm/month(44cm) 6-12 months :+ 0.5cm/month(47cm) 1-3 year : 0.25 cm/ mnth 3-6 year : 1 cm/year

7. History Examination including auscultation of the skull for bruit Developmental history Rate of head growth – serial measurements Investigations : Urea/electrolytes Thyroid function test Plasma amino acids Urine amino acids and organic acids, glycosaminoglycans CT head/MRI head preferably Bone profile APPROACH

8. TREATMENT -generally require no tx - Infants with hydrocephalus may require neurological intervention( e.g. placement of a ventriculo -peritoneal shunt).

9. MICROCEPHALY Definition : Head circumference < 3 SD below the mean for age, sex and gestation. Types : 1.Primary (Genetic) 2. Secondary (non-genetic)

10. 1. PRIMARY ( Genetic ) MICROCEPHALY Condition associated with reduced generation of neurons during neural development and migration. Refers to group - associated with specific genetic syndromes . Usually have slanting forehead . Identified at birth itself

11. Causes for primary Familial - AR Autosomal dominant Syndromes : Down Syndrome Cri du chat Edward Cornelia de Lange Rubinstein Tyabi

12. Results from noxious agents that may affect a fetus in utero or an infant during periods of rapid brain growth, particularly the first 2 years of life 2. Secondary ( non genetic) Microcephaly

13. Radiation Congenital infections – rubella, CMV, toxoplasmosis, HIV, Syphilis Drugs – fetal alcohol, fetal hydantoin Meningitis/encephalitis Metabolic – maternal diabetes Hypoxic ischemic encephalopathy Malnutrition Hyperthermia Causes for secondary microcepahaly

14. APPROACH History ( perinatal – family history) Examination – dysmorphic features – malformations Development Growth – serial measurements of HC INVESTIGATIONS Baseline biochemistry, metabolic screen Genetic testing – karyotype , molecular genetics TORCH screen Ophthalmology MRI brain

15. No treatment for microcephaly Baby’s head cannot be returned to a normal size & shape According to the cause Anticonvulsants Physiotherapy Hearing and speech therapy Dietary management for failure to thrive Genetic counseling Management

16. CRANIOSYNOSTOSIS Definition : premature fusion of one or more cranial sutures, either major( e.g metopic , coronal, sagittal , and lambdoid ) or minor( frontnasal , temporosquamosal , and frontosphenoidal ).

17. DEFORMITIES OF SKULL Plagiocephaly Scaphocephaly Trigonocephaly Turencephaly Brachycephaly

18. Fusion of either right or left side of the coronal suture -Causes the normal forehead and the brow to stop growing -Produces flattening of the forehead and the brow on the affected side, with the forehead tending to be excessively prominent on the opposite side PLAGIOCEPHALY

19. SCAPHOCEPHALY Early closure or fusion of the sagittal suture Fusion causes a long, narrow skull .Prominent occiput and forehead Usually only craniosynostosis which is relatively harmless

20. TRIGONOCEPHALY Fusion of the metopic (forehead) suture Fusion result in a prominent ridge running down the forehead -looks pointed, like a triangle, with closely placed eyes ( hypotelorism ).

21. Turriencephaly – cone shaped head . Fusion of coronal and speno frontal or fronto ethmoid sutures. Brachycephaly – premature closure of coronal suture expands skull parallel to coronal suture , thus broadening of forehead with short AP diameter. Eg – in many syndromes like Downs Syndrome

22. Diagnosis Palpation of suture reveals prominent bony ridge. Fusion may be confirmed by x-ray skull Associated syndromes – Crouzon , Alperts , Carpenter

23. Management Premature fusion of single suture rarely causes any neurological deficit . Thus, in this situation the only indication is cosmetics. 2 or more suture fusion – more complications eg . ↑ ICT, hydrocephalus, optic atrophy, DNS, choanal atresia --- operative surgery essential – craniectomy with craniofacial correction. Usually good prognosis with non syndromic infants……………

24. Thank You