Notencephalus is a rare congenital anomaly characterized by the absence or underdevelopment of the brain's cerebral hemispheres, commonly referred to as the cerebrum. It is a severe form of neural tube defect that occurs during early embryonic development when the neural tube fails to close properly. The cerebral hemispheres, responsible for higher brain functions such as consciousness, sensation, perception, and voluntary movement, are either completely absent or significantly reduced in size in individuals with notencephalus.
Affected individuals typically exhibit profound intellectual disability, and basic survival outside the womb is extremely rare. Other accompanying physical abnormalities may include facial deformities, such as a small or absent forehead, small eyes, an absent or underdeveloped nose, and a cleft lip or palate. Additionally, hydrocephalus, the accumulation of excessive cerebrospinal fluid within the brain, is often present, leading to an enlarged head.
Notencephalus is often detected prenatally through ultrasound or other prenatal screening methods, allowing parents to make informed decisions about their pregnancy. Unfortunately, there is no cure for notencephalus, and the condition is incompatible with life in most cases, resulting in fetal demise before birth or shortly after.
While there have been some reported cases where individuals with notencephalus have survived for a short period after birth, their neurological function is severely compromised, and they require extensive medical care and support.
