This document discusses various abnormalities of head size and shape, including macrocephaly, microcephaly, and craniosynostosis. It defines each condition and lists potential causes. For macrocephaly, causes include megalencephaly, increased cerebrospinal fluid, enlarged vascular compartment, increased bony compartment, and miscellaneous lesions or diseases. Microcephaly can be primary/genetic or secondary/non-genetic, with various infectious, toxic, metabolic, or hypoxic-ischemic causes provided. Craniosynostosis involves premature fusion of cranial sutures, which can result in deformities like plagiocephaly or scaphocephaly. The document outlines approaches to diagnosis and

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 :
1. Urea/electrolytes
2. Thyroid function test
3. Plasma amino acids
4. Urine amino acids and organic acids, glycosaminoglycans
5. CT head/MRI head preferably
6. 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 :
1. Down Syndrome
2. Cri du chat
3. Edward
4. Cornelia de Lange
5. 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. 1. Radiation
2. Congenital infections – rubella, CMV, toxoplasmosis,
HIV, Syphilis
3. Drugs – fetal alcohol, fetal hydantoin
4. Meningitis/encephalitis
5. Metabolic – maternal diabetes
6. Hypoxic ischemic encephalopathy
7. Malnutrition
8. 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).

18. DEFORMITIES OF SKULL
1. Plagiocephaly
2. Scaphocephaly
3. Trigonocephaly
4. Turencephaly
5. Brachycephaly

19. -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

20. 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

21. 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).

22. • 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

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

24. 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……………

25. Thank You