Megalencephaly is a birth defect that causes an infant to be born with a very large head and malfunctioning brain.
Macrocephaly is another medical term that describes this condition. Occasionally the infant will not be born with an abnormally large head when megalencephaly is present. In this case, the head will rapidly grow during the child's early years.
Common symptoms of megalencephaly include developmental delays, seizures, convulsive disorders and an abnormal brain cortex and spinal cord. Mental retardation is common with megalencephaly.
There is no cure for the disorder, but treatment options include various kinds of therapy and medications to control seizures.