Differential Diagnosis

• Single most likely diagnosis
  • Spinal epidural abscess: This diagnosis is highly likely given the patient's recent history of spinal surgery (cervicothoracic decompression and fusion, and laminectomy for resection of epidural mass infection), progressive upper back pain, weakness, numbness ascending from the feet, and recent history of IV drug abuse, which increases the risk of infection. The patient's symptoms of sweating, chills, and weight loss also suggest an infectious process.
• Other Likely diagnoses
  • Spinal cord compression or injury: Given the patient's history of neurogenic bladder, recent spinal surgeries, and progressive neurological deficits (weakness, numbness), spinal cord compression or injury is a plausible diagnosis. The recent surgeries could have caused or exacerbated spinal cord injury.
  • Discitis or osteomyelitis: These are infections of the intervertebral disc or vertebral body, respectively. The patient's recent spinal surgeries and history of IV drug abuse increase the risk of these infections, which could explain the patient's back pain, fever, chills, and weight loss.
  • Metastatic spinal cord compression: Although less likely given the patient's age and lack of known primary malignancy, metastatic spinal cord compression could cause progressive neurological deficits and back pain.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
  • Spinal hematoma: A spinal hematoma could cause rapid neurological deterioration and is a medical emergency. The patient's recent history of spinal surgery and anticoagulation (if used) increases the risk of this condition.
  • Cauda equina syndrome: This is a serious condition that requires prompt surgical intervention. Although the patient's symptoms are more suggestive of spinal cord involvement, cauda equina syndrome could cause similar symptoms, including numbness, weakness, and bowel/bladder dysfunction.
  • Meningitis: Given the patient's recent history of spinal surgery and IV drug abuse, meningitis is a potential diagnosis that could cause fever, chills, and neurological symptoms.
• Rare diagnoses
  • Spinal arachnoiditis: This is a rare condition characterized by inflammation of the arachnoid membrane surrounding the spinal cord. It could cause chronic back pain, numbness, and weakness.
  • Spondyloptosis: This is a rare condition where a vertebra slips over another, which could cause spinal cord compression and neurological deficits. However, this diagnosis is less likely given the patient's recent spinal surgeries and lack of trauma history.