Hello, Both of the conditions lumbar spinal stenosis and Parkinson s disease (PD) may cause a pinched nerve in the lower back and cause pain. Spinal stenosis may lead to curvature or bending of the spine by degenerative processes (e.g. degenerative scoliosis) and result in pressure on nerve roots. On the other hand Parkinson s disease patients also commonly have bending of the spine which result in pinched nerve with radical pain (sharp and travels along the nerve route). Furthermore, pain syndrome is experienced two times more in PD patients compared to the general population. MRI may be helpful to diagnose and distinguish pinched nerve from these conditions. Regardless of the cause, you should always try an exercise program before starting medications. Stretching and strengthening exercises will help you to improve your condition by maintaining a healthy weight, increasing blood flow to the area, strengthening spinal muscles and keeping the spine flexible. Hope I have answered your query. Let me know if I can assist you further. Regards, Dr. Malik