Damaged nerve fibers release local mediators, such as nerve growth factor (NGF) or tumor necrosis factor (TNF) which can cause damage to nearby and previously healthy nerve fibers [8]. The old term “central pain” refers to neuropathic pain caused by lesions of the central nervous system, such as post-stroke pain or pain with multiple sclerosis [8,9]. This evidence concerns the gene NGF and multiple sclerosis.