All cells have a cell membrane. its basically what protects the cells from getting toxins that are sometimes entering your body. without a membrane on all cells, you would get sick a lot!!
The answer is stroke. This means that formation of plaque in the blood vessels that serve the brain cause thickenning of the inner walls of the vessels. When the plaque ruptures, a blood clot forms and blocks blood passage to a particular region of the brain served by the vessel. This stifles oxygen supply to the respective part of the brain leading to the death of the cells in the region.
Atoms become ions by gaining or losing electrons. When two ions join together, they form a bond known as an Ionic bond.
I really think that its the second one; Nihilist