Please see the discussion on Requests for cleanup for more information and remove this template after the problem has been dealt with. 1  Afep pigeon (Columba unicincta) 2  African owl pigeon (Columba livia domestica) 3  African green pigeon (Treron calvus) 4  African olive pigeon (Columba arquatrix) 5  American pigeon (Patagioenas)
Fatal familial insomnia and sporadic fatal insomnia differ from other prion diseases because they affect predominantly one area of the brain, the thalamus, which influences sleep. The familial and sporadic forms typically begin between the ages of 30 and 50 years.
Spina bifida progresses from a cleft, or splitlike opening, in the back part of the backbones (the spinal vertebrae). In more severe cases, it involves the spinal cord. Spina bifida is the most common of a group of birth defects known as neural tube defects, which affect the central nervous system (brain and spinal cord). Spina bifida begins in the womb, when the tissues that fold to form the neural tube do not close or do not stay closed completely.