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.
A. A. A. Multiple sclerosis, or MS, is a long-lasting disease that can affect your brain, spinal cord, and the optic nerves in your eyes. It can cause problems with vision, balance, muscle control, and other basic body functions. The effects are often different for everyone who has the disease.
Corticobasal Degeneration. Corticobasal degeneration (CBD) is a rare neurological disease associated with progressive brain degeneration. The disease, also known as corticobasal ganglionic degeneration, leads to the loss of brain tissue in the cortex, or outer layer of the brain, especially the area in the upper, front section of the brain.