you need to get an MRI lumbar spine to consider the paresthesiae in the lower limbs.
Muscle cramps can be due to simple causes like
muscle fatigue, heavy exercise, dehydration, hypothyroidism, hypomagnesemia and hypocalcemia, side effectsof drugs like diuretics, caffeine. muscle cramps are cause by more serious neurological causes like motor neuron disease, muscle diseases, denerevation usually accompanied by weakness and atrophy of the affected muscle group etc.