The medical evaluation begins with a complete medical history and physical examination to get clues to the diagnosis of lumbar spinal stenosis. During the medical history, the patient will be asked questions regarding symptoms, including how long they have been present, what makes them better or worse, what prior treatment the patient has had, and what other medical conditions they have. These questions can also help the doctor distinguish lumbar spinal stenosis from other disorders that may produce similar symptoms.
The physical examination often consists of testing the range of motion in the back and feeling for areas of tenderness in the back. The legs may be examined for range of motion, strength, sensation, reflexes, and pulses. The hips and knees may also be examined because problems with these joints can often causes symptoms similar to those of lumbar spinal stenosis.
After the examination, the physician may order imaging studies to detect anatomic signs of lumbar spinal stenosis. This often begins with plain X-rays of the spine. The doctors may also order an X-ray of the patient's pelvis and hips, depending on findings from the physical examination. The X-rays can show the doctor various signs associated with spinal stenosis, including loss of the normal intervertebral disc height, the presence of bone spurs (osteophytes), and spinal instability (abnormal motion between the vertebrae). The ultimate diagnosis of lumbar spinal stenosis is made by an MRI scan (magnetic resonance imagining scan) or CT scan (CAT scan or computerized axial tomography). These are more advanced tests that are used to visualize the nerves in the lower back and detect if they are being compressed from lumbar spinal stenosis.
In some cases, special nerve tests, including electromyogram (EMG) or nerve conduction studies, may be ordered. These tests can identify damage to or irritation of the nerves caused by long-term compression from lumbar spinal stenosis. These tests can also help determine exactly which nerves are involved.