In this review, we conducted a search of the PubMed database from January 1990 to March 2021, using the terms “macrocephaly,” “macrocrania,” “megalencephaly,” “hemimegalencephaly,” “relative macrocephaly,” “congenital/primary macrocephaly.” Additional references that were cited in relevant articles were also used. However, the increasing use of Next Generation Sequencing (NGS) in the last decade has allowed the identification of several novel genetic disorders associated with macrocephaly, challenging their genetic diagnosis in a clinical setting. From a clinical point of view, some features including cutaneous and vascular anomalies and several craniofacial dysmorphisms have helped physicians to recognize specific neurogenetic disorders presenting with macrocephaly. Neuroimaging has classically played a major role in the evaluation of macrocephaly helping to distinguish acquired causes from congenital abnormalities ( 2). The differential diagnosis is indeed very broad requiring a systematic approach including clinical history, physical examination, and neuroradiological evaluation. Therefore, it is fundamental for clinicians to recognize the clinical hallmarks of these conditions to reach the correct diagnosis. Macrocephaly can also be a sign of serious acquired conditions such as progressive hydrocephalus, vascular anomalies, or intracranial masses that may necessitate urgent intervention. It encompasses a broad range of clinical entities ranging from benign familial macrocephaly and Benign External Hydrocephalus (BEH) to more than 200 genetic disorders. Macrocephaly is a relatively common clinical condition affecting up to 5% of the pediatric population ( 1). We thus provide a clinico-radiological algorithm to guide pediatricians in the assessment of children with macrocephaly. In this review, we seek to underline the clinical aspects of macrocephaly and megalencephaly, emphasizing the main differential diagnosis with a major focus on common genetic disorders. Apart from the head size evaluation, a detailed family and personal history, neuroimaging, and a careful clinical evaluation are crucial to reach the correct diagnosis. While macrocephaly can be isolated and benign or may be the first indication of an underlying congenital, genetic, or acquired disorder, megalencephaly is most likely due to a genetic cause. Moreover, macrocephaly should be differentiated by megalencephaly (MEG), which refers exclusively to brain overgrowth, exceeding twice the SD (3SD-“clinically relevant” megalencephaly). This implies the urgent need for a diagnostic workflow to use in the clinical setting to dissect the several causes of increased OFC, from the benign form of familial macrocephaly and the Benign enlargement of subarachnoid spaces (BESS) to many pathological conditions, including genetic disorders. Taking into account that about 2–3% of the healthy population has an OFC between 2 and 3 SD, macrocephaly is considered as “clinically relevant” when OFC is above 3 SD. Macrocephaly affects up to 5% of the pediatric population and is defined as an abnormally large head with an occipitofrontal circumference (OFC) >2 standard deviations (SD) above the mean for a given age and sex.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |