Multiple sclerosis (MS) is a potentially disabling disease of the brain and spinal cord (central nervous system).In MS, the immune system attacks the protective sheath (myelin) that covers nerve fibers and causes communication problems between your brain and the rest of your body. The cause of MS is unknown and its pathophysiology remains poorly understood Among the unanswered questions is whether MS is a single disease. It could be that different antigens are involved in different patients, different T-cells are activated, or the mechanisms of cell damage are different. This book is a set of guidance documents has been made available to assist doctors and their patients who choose to prescribe medicinal cannabis.