Macrocephaly

Macrocephaly is a clinical and radiological term that refers to a generalized increase in the size of the cranial vault.

Terminology

This slightly differs from the term megalencephaly which means an increase in the size of the brain parenchyma. 

Epidemiology

• content pending

Clinical presentation

In some individuals a large head is normal or something that is familial.

However in others it is related to a syndrome, and other features may be present, see long list of causes below. 

Pathology

Etiology

In an infant it can result from a wide range of causes:

• congenital hydrocephalus: this, in turn, can result from a multitude of causes
• hydranencephaly: the choroid still forms CSF
• subdural fluid collection
• neurofibromatosis type 1
• achondroplasia
• hypochondroplasia
• thanatophoric dysplasia
• tuberous sclerosis complex
• metabolic storage diseases, e.g. mucopolysaccharidoses
• Alexander disease
• Greig syndrome
• Gorlin-Goltz syndrome
• Ruvalcaba syndrome
• Canavan disease ³
• cranio-cerebello-cardiac (CCC) syndrome
• Sotos syndrome
• Bannayan–Riley–Ruvalcaba syndrome (BRRS) ¹
• arterial tortuosity syndrome
• Weaver syndrome
• fragile X syndrome
• Noonan syndrome
• Costello syndrome
• LEOPARD syndrome

Radiographic features

Some define the condition on skull radiography when the head circumference is more than two standard deviations above the mean or exceeds the 97^th percentile by at least 0.5 cm ⁴.

See also

• benign enlargement of the subarachnoid spaces in infancy as a benign cause of macrocephaly
• fetal macrocephaly