What Causes Severe Leg Cramps?

I take a multi-vitamin, plus magnesium and potassium once in a while, but still have horrendous leg cramps at night. I only take potassium occasionally when I don t eat enough potassium-rich foods. I m 68, and really healthy. 5 8 size 10, 158 lbs. I had a mild stoke 2-22-15 but have almost fully recovered. Not a TIA but a stroke according to the MRI. There is now a brain abnormality. No paralysis, I maintained great strength but no control on the right side. All tests in the hospital were negative. I don t smoke, drink, use drugs. With all tests coming back in the normal range….why the stroke and why the leg cramps? My only vises…..sugar, 1 caffein pill a day (I m allergic to coffee) and I cuss like a sailor when I m driving. The !@#!!*&! drivers in Florida would make a saint curse. Thanks so much! Karen