Differential Diagnosis
The patient presents with bilateral posterior leg pain and progressive lower extremity weakness. Based on the symptoms and history, the following differential diagnoses are considered:
- Single most likely diagnosis
- Lumbar Radiculopathy or Spinal Stenosis: The patient's symptoms of bilateral posterior leg pain, weakness, and difficulty initiating standing from a seated position are consistent with lumbar radiculopathy or spinal stenosis. The improvement in pain with ambulation also supports this diagnosis.
- Other Likely diagnoses
- Venous Insufficiency or Varicosities: The patient's history of varicose veins and symptoms of leg discomfort, particularly when sitting for prolonged periods, suggest venous insufficiency as a contributing factor.
- Functional Vitamin B12 Deficiency: Despite normal serum B12 levels, the patient's ongoing neurologic complaints and difficulty with leg elevation suggest a possible functional vitamin B12 deficiency.
- Neuromuscular Etiology: The patient's generalized weakness and difficulty with leg elevation suggest a possible neuromuscular etiology, such as a myopathy or muscular dystrophy.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Cauda Equina Syndrome: Although the patient reports no bowel or bladder changes, cauda equina syndrome is a medical emergency that requires prompt attention. The patient's symptoms of progressive lower extremity weakness and difficulty with leg elevation warrant consideration of this diagnosis.
- Spinal Epidural Abscess: This is a rare but potentially life-threatening condition that can present with symptoms of back pain, weakness, and difficulty with ambulation.
- Rare diagnoses
- Peripheral Artery Disease: Although the patient's symptoms are more consistent with venous insufficiency, peripheral artery disease is a possible cause of leg pain and weakness, particularly in older adults.
- Amyotrophic Lateral Sclerosis (ALS): The patient's symptoms of progressive lower extremity weakness and difficulty with leg elevation are consistent with ALS, although this diagnosis is relatively rare and would require further evaluation to confirm.