Setting aside the notion of determining the number of individual animals on the planet for a moment, merely determining the number of species on the Earth is challenging. Science has only been able to offer estimates thus far, and totals vary greatly.
People who have early onset Alzheimer's may be in any stage of dementia â early stage, middle stage or late stage. The disease affects each person differently and symptoms will vary. If you are experiencing memory problems: 1  Have a comprehensive medical evaluation with a doctor who specializes in Alzheimer's disease.
Symptoms of White Matter Brain Disease. White matter brain disease results in the degeneration of white matter, which creates a large portion of the brain. The primary form of white matter brain disease is multiple sclerosis, which results in the destruction of the myelin sheath. In multiple sclerosis, there is defective formation or maintenance of the myelin because of dysfunction of the oligodendrocytes, a type of glial cell.