Diagnostic Approach to Macrocephaly in Children

Area of Science:

• Pediatric Neurology
• Clinical Genetics
• Neuroimaging

Background:

• Macrocephaly, defined as occipitofrontal circumference (OFC) >2 standard deviations (SD) above the mean, affects up to 5% of children.
• Clinically relevant macrocephaly is typically considered when OFC exceeds 3 SD, necessitating differentiation from benign familial macrocephaly and Benign enlargement of subarachnoid spaces (BESS).
• Macrocephaly can be isolated and benign or indicate underlying congenital, genetic, or acquired disorders, whereas megalencephaly (MEG) exclusively signifies brain overgrowth, often with a genetic basis.

Purpose of the Study:

• To review the clinical aspects of macrocephaly and megalencephaly in pediatric populations.
• To emphasize differential diagnoses, with a focus on common genetic disorders associated with increased head size.
• To provide a clinico-radiological algorithm to assist pediatricians in assessing children with macrocephaly.

Main Methods:

• Review of clinical and radiological findings in pediatric macrocephaly and megalencephaly.
• Emphasis on differentiating benign conditions from pathological causes, particularly genetic disorders.
• Development of a diagnostic algorithm integrating clinical evaluation, family history, and neuroimaging.

Main Results:

• Macrocephaly presents a spectrum from benign familial cases to indicators of significant underlying pathology.
• Megalencephaly is strongly associated with genetic etiologies.
• A systematic diagnostic approach combining clinical assessment, history, and imaging is crucial for accurate diagnosis.

Conclusions:

• Accurate differentiation between macrocephaly and megalencephaly is essential for appropriate management.
• Genetic disorders are a significant consideration in cases of megalencephaly and some forms of macrocephaly.
• The proposed clinico-radiological algorithm provides a practical framework for pediatricians managing children with macrocephaly.