Despite the wide range in its implications, encephaloceles are most likely to be caused by improper separation of the surface ectoderm and the neuroectoderm after the closure of the neural folds in the fourth week of gastrulation. Hydranencephaly
Hydranencephaly is a condition in which the cerebral hemispheres are missing and instead filled with sacs of cerebrospinal fluid. People are born with hydranencephaly, but most of the time, the symptoms appear in a later stage. Newborns with hydrancephaly can swallow, cry, sleep and their head is in proportion to their body. However, after a few weeks, the infants develop increased muscle tone and irritability. After a few months, the brain start to fill with cerebrospinal fluid (hydrocephalus). This has several consequences. Infants start to develop problems with seeing, hearing, growing, and learning. The missing parts of the brain and the amount of cerebrospinal fluid can also lead to seizures, spasm, problems with regulating their body temperature, and breathing and digestion problems. Besides problems in the brain, hydranencephaly can also be seen on the outside of the body. Hydrocephalus leads to more cerebrospinal fluid in the brain, which can result in an enlarged head.The cause of hydranencephaly is not clear. Hydranencephaly is a result of an injury of the nervous system or an abnormal development of the nervous system. The neural tube closes in the sixth week of the pregnancy, so hydranencephaly develops during these weeks of the pregnancy. The cause of these injuries/development is not clear.
In the seventeenth century the Sauk also maintained close relations with the Potawatomi (Pehkînenîha or Shîshîpêhinenîha). This relation has been found by borrowings of Sauk vocabulary that appear in the Potawatomi language. In a loose coalition of tribes – including Dakota (Ashâha), Ojibwe, Odawa, Potawatomi, Kickapoo (Kîkâpôwa), Meskwaki (Fox), and Sauk, along with the Shawnee (Shâwanôwa), Cherokee (Shanahkîha), and Choctaw (Châkitâha) from the Southeast – they attacked the tribes of the Illinois Confederation ("Illinois/Inoca") (Mashkotêwa) and tried to invade their tribal areas. The "Illinois/Inoca" became their worst common enemies. The coalition warred for years until they destroyed the Illinois Confederation. Later they moved out on the prairie (Mashkotêwi) along the Mississippi and adopted the semi-sedentary lifestyle of Plains Indians (Mashkotêwineniwa). In addition to hunting buffalo, they lived in villages, raised crops, and actively traded with other tribes. The Sauk and allied eastern tribes had to compete with tribes who already occupied this territory. Disputes and clashes arose with the Dakota, Pawnee (Pânîha) and, most of all, the powerful Osage (Washâsha). The Sauk had good relations with the English (Thâkanâsha) through trading. At first, the Sauk had good relations with New France too, until their alliance with the Meskwaki (Fox) made them short-term enemies of the French (Mêmehtekôshîha, Wêmehtekôshîha). A closely allied tribe, the Meskwaki (Fox), were noted for resisting French encroachment, having fought two wars against them in the early 18th century.