Spinal Cord Injury from Fluoroscopically Guided Intercostal Blocks with Phenol

Abstract

Background: Image guided intercostal blocks are commonly performed and considered relatively safe. Chemical denervation is commonly used in clinical practice for treatment of chronic noncancer associated pain. Objective: To report a case of spinal cord injury resulting from fluoroscopically guided intercostal blocks with phenol. Study Design: Case report. Setting: Inpatient hospital service. Results/Case Report: A 53 year-old women was transferred from her local facility for acute onset of lower extremity paresis beginning shortly after right intercostal nerve injections of 2 mL of preservative-free phenol at the T7, 8, 9 levels. She had previous intercostal blocks for chronic rightsided mid thoracic/abdominal pain every 3 months for at least one year without sequelae. Within 20 minutes of the injection, she developed a sensation of right leg weakness and heaviness. Over several hours she developed worsening right leg weakness, and then left leg weakness, followed by urinary retention. Admission examination revealed severe right greater than left leg weakness, right lower extremity hyperesthesia to T10, absent lower extremity reflexes, and bilateral extensor plantar responses. Magnetic resonance imaging (MRI) of the entire spine demonstrated extensive T2/DWI hyperintensity in the central spinal cord from T1 to L1 with mild cord enlargement and enhancement at T7-9 (sites of injection). Extensive serum and cerebrospinal fluid (CSF) evaluation did not show any evidence of an infectious, inflammatory, or metabolic cause to her myelopathy. Repeat MRI of the entire spine demonstrated near complete resolution of the T2 signal abnormality. One month after presentation, despite radiographic improvement, the patient showed some clinical improvement, but remained walker dependent and with neurogenic bowel and bladder. Limitations: This report describes a single case report. Conclusion: This case offers several lessons for a pain specialist including 1) the potential for a neurologic catastrophe (spinal cord injury) from aqueous neurolytic intercostal blocks despite “safe” contrast spread; 2) potential mechanisms of neurogenic injury with intercostal blocks; 3) review of modifiable factors to decrease the risk of neurogenic injury; and 4) review of potential interventions (steroids, lumbar drain) to improve outcome in the setting of iatrogenic procedural related spinal cord injury. Key words: Phenol, myelopathy, paraparesis, chemical denervation, neurolysis, intercostal block, epidural spread, chronic pain, complication, transverse myelitis