Macrocephaly: Solving the Diagnostic Dilemma

Area of Science:

• Pediatric Neurology
• Clinical Genetics
• Medical Imaging

Background:

• Macrocephaly affects up to 5% of children, defined by an occipitofrontal circumference >2 standard deviations above the mean.
• Megalencephaly specifically denotes brain overgrowth exceeding twice the standard deviation.
• Macrocephaly can be isolated and benign, or indicative of congenital, genetic, or acquired disorders; megalencephaly is often syndromic.

Purpose of the Study:

• To outline the diverse etiologies of macrocephaly.
• To delineate the clinical and radiographic features of macrocephaly subtypes.
• To propose a clinicoradiological algorithm for evaluating pediatric macrocephaly.

Main Methods:

• Literature review of macrocephaly and megalencephaly etiologies.
• Analysis of clinical presentations and neuroimaging findings.
• Development of a diagnostic algorithm based on clinicoradiological data.

Main Results:

• Macrocephaly encompasses various conditions, from benign variations to syndromic presentations.
• Megalencephaly subtypes include metabolic and developmental, linked to cellular metabolism defects and signaling pathway alterations.
• Neuroimaging is crucial for identifying macrocephaly, particularly the less clinically apparent metabolic subtype.

Conclusions:

• A systematic clinicoradiological approach aids in diagnosing the underlying cause of pediatric macrocephaly.
• Differentiating benign macrocephaly from syndromic forms is essential for appropriate management.
• Understanding the diverse etiologies and features guides effective evaluation strategies.