Why do you get pachygyria?
It all begins in very early pregnancy. The embryo's brain forms
during the first month of pregnancy, all the nerve cells are
located in the center surrounding a fluid-filled cavity called the
central canal. During the second month, support cells begin to send
branches up to the surface of the brain. During the third and
fourth months, the nerve cells climb up these branches to reach the
surface. Each wave of nerve cells climbs above the preceding waves
so that the last wave of cells is closest to the surface. Normally,
a large majority of all nerve cells are located at or just under
the surface in an area called the cortex. In pachygyria, many of
the nerve cells do not reach the surface. They are stuck in an
abnormal position, and so cannot make their usual connections with
other nerve cells. Causes include untreated viral infections of the
uterus or the fetus during the first trimester, or insufficient
blood supply to the fetal brain early in pregnancy, drug or
medication abuse in the 3-4 month of pregnancy or genetic
mutations.