Differential Diagnosis for Lower Back Pain with Radiating Leg Pain
The patient's symptoms of gradually worsening lower back pain associated with severe, episodic, shooting pain in the left buttock and down the back of the leg, aggravated by coughing, sneezing, or sudden movement, and relieved by indomethacin (indocid), suggest a condition affecting the lumbar spine. Here is a categorized differential diagnosis:
Single most likely diagnosis
- Lumbar Disc Herniation: The patient's symptoms of severe, episodic, shooting pain in the left buttock and down the back of the leg, exacerbated by activities that increase intrathecal pressure (coughing, sneezing), are highly suggestive of a lumbar disc herniation, particularly at the L4-L5 or L5-S1 level. The relief with indomethacin also supports an inflammatory component, which is common in disc herniations.
Other Likely diagnoses
- Lumbar Spondylosis: This condition involves degenerative changes in the lumbar spine, which can cause lower back pain and radiating leg pain due to foraminal stenosis or facet joint osteoarthritis.
- Lumbar Spinal Stenosis: Narrowing of the lumbar spinal canal can cause neurogenic claudication, characterized by pain, numbness, or weakness in the legs and buttocks, worsened by standing or walking and relieved by sitting or leaning forward.
- Sacroiliitis: Inflammation of the sacroiliac joints can cause lower back pain that radiates to the buttocks and legs, and can be exacerbated by movement.
Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Cauda Equina Syndrome: A medical emergency characterized by low back pain, bilateral sciatica, saddle anesthesia, and bowel or bladder dysfunction due to compression of the cauda equina. Prompt recognition and surgical intervention are crucial to prevent permanent neurological damage.
- Spinal Infection (e.g., Discitis, Osteomyelitis): Infections of the spine can cause severe back pain, fever, and neurological deficits. Early diagnosis and treatment are essential to prevent serious complications.
- Spinal Tumor: Both primary and metastatic tumors can cause back pain and neurological symptoms. A thorough evaluation, including imaging studies, is necessary to rule out this potentially life-threatening condition.
Rare diagnoses
- Arachnoiditis: Inflammation of the arachnoid membrane surrounding the spinal cord can cause severe, chronic pain and neurological symptoms.
- Tarlov Cysts: Fluid-filled sacs that can compress nerve roots, causing lower back and leg pain.
- Piriformis Syndrome: Compression of the sciatic nerve by the piriformis muscle can cause buttock and leg pain, although this is less likely given the patient's specific symptoms and relief with indomethacin.