Infectious causes include Amyloid or Prion infections, that affect the brain and spinal cord central nervous system, and derived from a scrapie-like factor, a disease affecting sheep. Other risk factors include a family history of Alzheimer's disease, a mutation of the APOE gene, Parkinson's disease, apolipoprotein E-4, alcohol abuse, depression, head trauma, lack of mental stimulation, long-term electromagnetic exposure, and free radical damage... Full Text