Microcephaly with a simplified gyral pattern

Comparison with a normal 2 weeks old newborn.

Note the profound microcephaly and the small corpus callosum at the sagittal image.

Also, the severe simplified gyral pattern seen on the axial images.

Microcephaly with a Simplified Gyral Pattern (MSG) is a congenital disorder characterised by microcephaly and shallow (reduced number of) gyri.

Lissencephaly is similar to MSG however, in lissencephaly the cortex is thick showing an abnormal architecture, both features are usually absent in MSG.

MSG may show corpus callosum hypogenesis or hypoplasia, hypomylinationhypomyelination, or periventricular nodular heterotopia.

Microcephaly is classified into:

• primary: microcephaly with normal brain architecture. The cause is likely genetic. In some cases, this primary type may show a simplified gyral pattern without cortex thickening
• secondary: microcephaly secondary to cerebral cortical malformation (e.g. holoprosencephaly or lissencephaly). The cause is likely secondary to brain insults, such as hypoxic-ischaemic insult or infection, or metabolic disorder

The case is courtesy of Dr.Mostafa El Khashab, MD of radiodiagnosis