Hello, You have history of MS, presently you are experiencing sharp pain in the upper thigh, it is of the stabbing sting type and its sporadic. It hurts you only when yo are walking upright. Remedy of the sharp pain depends on the treatment of the cause. Applying warm compression and ice will improve many causes of thigh pain. Take pain relieving medications and adequate water to get rid of crampy pain. Do not over exhaust or stress the affected thigh, stay at rest. Keep it elevated on the stool when sitting and on a pillow when on bed. To prevent pain due to stress, take home made, balanced nutritious diet. In the long run weight loss and physical therapy may help. Peripheral neuropathy can cause pains in the upper thigh that are felt in the outer thigh, inner thigh, and lower leg. Control your blood glucose level at all cost. Avoid wearing tight clothing s and lose weight, do regular walking and exercises. Sciatica can cause pain in the front of the thigh. Sciatica is caused by compression of a nerve as it exits the spinal cord, resulting in pain that may radiate from the back down the thigh. Get clinically examined by a GP, get blood workouts and tests done so that treatment can be started at the earliest. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Nupur K., General & Family Physician