brain disease megalencephaly (disease) true SCTID:9740002 https://www.ncbi.nlm.nih.gov/pubmed/28658095 megalencephaly macroencephaly MESH:D058627 MONDO:0016608 MedDRA:10050183 A congenital abnormality in which the occipitofrontal circumference is greater than two standard deviations above the mean for a given age. It is associated with hydrocephalus; subdural effusion; arachnoid cysts; or is part of a genetic condition (e.g., alexander disease; sotos syndrome). http://www.case.edu/EpSO.owl#Megalencephaly Orphanet:2477 ICD10:Q04.5 ICD9:742.4 HP:0001355