Spinal Cord Infarction Following Zoledronic Acid Administration in a Patient With Metastatic Prostate Cancer

Abstract

Spinal cord infarction is a rare but serious complication that can occur in the setting of metastatic disease, prior radiation therapy, and vascular compromise. We present a case of a 69-year-old male who was admitted to inpatient rehabilitation following an acute spinal cord infarction. Past medical history included metastatic prostate cancer, osteoporosis, deep vein thrombosis on apixaban, and a complex oncologic and spinal history. He experienced a sudden onset of back pain that progressed to bilateral leg paralysis and bowel and bladder dysfunction. His symptoms presented within 24 hours of receiving intravenous zoledronic acid for metastatic bone disease. Imaging revealed T2 signal changes suggestive of spinal cord infarction and new syringohydromyelia. Neurology suspected ischemia of the artery of Adamkiewicz in the context of metastatic disease, prior radiation, and bisphosphonate exposure. During inpatient rehabilitation, the patient demonstrated gradual motor recovery, improved sitting balance, and increased functional independence with therapy, despite experiencing persistent bowel and bladder incontinence. He developed a urinary tract infection and later hematuria, which required hospital readmission. He was then discharged to a skilled nursing facility for continued rehabilitation. This case highlights an uncommon but devastating neurologic complication in the context of complex oncologic care and prompts the consideration of potential vascular risks of bisphosphonates in patients with prior spinal metastases, radiation, and surgery. It also emphasizes the diagnostic complexity and the potential for rehabilitation in spinal cord infarction with multifactorial oncologic and vascular compromise.

Keywords: bisphosphonates; metastatic prostate cancer; spinal cord infarction; spinal cord injury; zoledronic acid.

Figure 1. Thoracic spine MRI taken on ED admission shows postoperative changes

T-spine MRI showing postoperative changes from the laminectomy at T10 (orange arrows), changes from transpedicular fusion at T8-12 (green star), T2 hyperintensity in the spinal cord from T3 (red arrow) to T7, and multiple metastatic deposits present in the thoracic spine, especially at T10 (yellow arrow).

Figure 2. Cervical spine MRI on day two of hospital admission showed degenerative disc disease

A cervical MRI on day two of hospital admission showed degenerative disc disease at C3-C6 (red arrows), but normal cord signal intensity.