Back to Top Megalencephaly Also known as macrencephaly, this condition is marked by an abnormally large, heavy, usually malfunctioning brain. The head may be enlarged at birth or become abnormally large in the early years. Megalencephaly is thought to be caused by some disturbance in the process which controls the way nerve cells divide to form new generations of cells. Males are more likely to be afflicted than females. Treatment is symptomatic.
Prognosis varies according to the severity of the condition's associated neurological disorders.
Megalencephaly may lead to another condition called macrocephaly. This results in a large, often asymmetrical head. Unilateral megalencephaly usually results in mental retardation and severe seizures. Prognosis for those afflicted is poor. Back to Top Microcephaly Children born with microcephaly have heads whose circumference is markedly smaller than normal for their age and sex.