1) Macrocephaly is defined as a head circumference (HC) more than two standard deviations above the mean for a patient's age and gender. HC is measured around the occiput and supraorbital ridges using a flexible tape. 2) Common causes of macrocephaly include hydrocephalus, megalencephaly, thickening of the skull, and brain edema from toxic or metabolic issues. Hydrocephalus is excess cerebrospinal fluid in the skull, while megalencephaly is enlargement of the brain. 3) Evaluation of macrocephaly involves obtaining a medical history, physical exam including head size and neurological assessment, and imaging tests such as MRI or CT of the brain

1. Dr. Praveen unki

2. Definition:
Macrocephaly is defined as an HC more
than two standard deviations above the
mean for the patient's age and gender.

3. Method for HC measurement :
Obtained with a flexible non-stretchable
measuring tape pulled tightly across the most
prominent part on the back (occiput) and
front (supraorbital ridges) of the head.

4. Normal Occipitofrontal circumference (OFC)
At Birth- 33-35 cm
Age HC Growth (cm/month)
0-3 mths 2
3-6 mths 1
6-9 mths 0.5
9-12 mths 0.5
1-3 yrs 0.25
4-6 yrs 1 cm/yr
Nelson’s Texbook of Pediatrics 21th Ed
At 5 year boys
Upper normal– 54 cm
Lower normal- 46 cm

5. Standardized HC charts
 World Health Organization:0-60 months
 CDC charts : 0-36 months
 Others-
Charts for premature infants
Down syndrome (CDC charts)
IAP Charts

6. WHO HC Chart –Boys-
Birth to 5year

7. WHO HC Chart- Girls-
birth to 5years

8. Red Flag signs:
 Head growth > 1.5 cm in 15 days
 Crossing centile
 Abnormal suture separation
 Sun-setting
 Feeding issue
 Signs of Raised ICP.

9. Macrocephaly: causes- overview
Hydrocephalus
Congenital , Infectious
Neoplastic ,
Posthemorrhagic ,
Hydranencephaly
Magalencephaly
( Excess amount of normal
brain constituents , storage of
metabolites and cellular
proliferation )
Subarachnoid
Cyst
Subdural
Effusion
( Hemorrhagic ,
infectious and
Hygroma )
Skull
( osteopetrosis
Achondroplasia )

10. Causes of large head-
 Excessive volume of cerebrospinal fluid in the skull -Hydrocephaly
 Enlargement of the brain- Megalencephaly
 Thickening of the skull
 Brain edema- toxic/metabolic
 Hemorrhage into the subdural or epidural spaces

11. Early Infantile Late Infantile Early to Late Childhood
-Hydrocephalus
a) Congenital disorders
( Spina Bifida , Chiari
malformations,
Aqueductal stenosis )
b) Mass lesions
(Neoplasms , AV
malformations, Cong
Cysts)
c) IU Infections
d)Peri or postnatal
infections
e)Peri or postnatal
hemorrhage
f)Hydranencephaly
-Subdural effusions
-Normal variant
-Hydrocephalus
a) Mass lesions
(Neoplasms , AV
malformations , Cong
Cysts)
b)Post bacterial or
granulomatous
c)Post hemorrhagic
(trauma , A-V
malformations)
d)Dandy Walker syndrome
-Primary skeletal
-Cranial Dysplasia
-Pseudotumor cerebri
-Megalencephaly
a)Metabolic CNS Disease
(Leukodystrophy ,
Lipidosis, MPS)
b)Neurocutaneous
syndromes
c)Cerebral Gigantism (
Sotos’ syndrome )
d)Primary megalencephaly
-Hydrocephalus
a)Aqueductal stenosis
b)Post infectious
c)Hemorrhagic
d)Chiari type 1
-Megalencephaly
a)Neurocutaneous
syndrome
b)Familial
-Pseudotumor cerebri
-Normal variant

12. History:
 Details of antenatal/perinatal period
 Obtain birth OFC, weight, height
 Family history of large head
 Developmental history
 Poor feeding, vomiting, irritability and
disturbed sleep pattern – raised ICP or
inborn error of metabolism

13. Physical examination:
 Dysmorphism
 Weight, height, OFC, US:LS ratio
 Neurocutaneous markers.
 Size and contour of AF- normally slightly
concave
 Palpate sutures
 Fundus examination- papilledema, cherry red
spot
 Intercanthal distance- hypertelorism
 Bruit over fontanel, carotids, eyes
 Complete neurological examination

14. Investigations
 CBC
 CSF study - if indicated
 TB workup.
 MRI head.
 CT brain.
 Work up for Intrauterine infection
 Radiographic bone survey for
dysmorphic or dysplastic patients
 Metabolic screening for inborn errors

15. Hydrocephalus- causes
Communicating Non Communicating
Achondroplasia
Basilar impression
Benign enlargement of
subarachnoid space
Choroid plexus papilloma
Meningeal malignancy
Meningitis
Post hemorrhage
Abscess
Aqueductal stenosis
Chiari malformation
Dandy-Walker malformation
Hematoma
Infectious
IU Infection
Klippel-Feil syndrome
Mass lesions
Tumors and neurocutaneous
disorders
Vein of Galen malformation
Walker-Warburg syndrome
X-linked
1) Communicating
2) Non-communicating
3) Hydrencephaly

16. Causes of Megalencephaly
Anatomical Metabolic
Genetic megalencephaly
Megalencephaly with
achondroplasia
Megalencephaly with gigantism
(Sotos syndrome)
Megalencephaly with
neurological abnormality
Neurocutaneous disorders
Epidermal nevus syndrome
Hypomelanosis of Ito
Incontinentia pigmenti
Neurofibromatosis
Tuberous sclerosis
Canavan disease
Galactosemia: transferase
deficiency
Gangliosidosis
Globoid leukodystrophy
Glutaric aciduria type I
Maple syrup urine disease
Megalencephalic
leukoencephalopathy with
subcortical cysts
Metachromatic leukodystrophy
Mucopolysaccharidoses
1) Anatomical
2) metabolic

17. Conditions with a Thickened
Skull Causing Macrocephaly
 Anemia- hemolytics
 Cleidocranial dysostosis
 Craniometaphyseal dysplasia of Pyle
 Epiphyseal dysplasia
 Hyperphosphatemia
 Orodigitofacial dysostosis
 Osteogenesis imperfecta
 Osteopetrosis
 Pyknodysostosis
 Rickets
 Russell dwarf

18. Treatment:
Medical
Treatment
Acetazolamide, Mannitol
Shunt VP shunt , VA shunt ,
Lumboperitoneal shunt
Bypass Ventriculocysternostomy
Third ventriculostomy
Decreased secretion Choroid plexus Extirpation
Treatment of underlying cause Removal of
a tumor

19. Thank you