Innovative Approaches to Severe Intractable Cancer Pain Due to Malignant Psoas Syndrome

Abstract

Malignant psoas syndrome (MPS) is associated with proximal lumbosacral plexopathy and is characterized by severe intractable pain, despite multimodal medical treatment. Spinal dexmedetomidine and lumbar sympathetic nerve block in combination with pulsed radiofrequency (PRF) are rarely performed for intractable lumbosacral plexopathy pain. We present a combination of spinal dexmedetomidine lumbar sympathetic nerve block and caudal-epidural PRF in the management of MPS, refractory to medical and physical treatment. A 49-year-old female with recurrent lung adenocarcinoma was admitted with shooting pain on the right side over the psoas muscle with irradiation into the right groin and weakness of quadriceps at motion. She was managing her pain with a number of opioids, including oxycodone, morphine, fentanyl, and intramuscular meperidine. The total oral morphine equivalent opioid dose equaled 460 mg. At the first admission, we successfully palliated pain with spinal dexmedetomidine and simultaneously reduced the patient’s opioid addiction. On the second admission, lumbar sympathetic nerve block at L3 with additional caudal-epidural PRF led to a significant reduction in her thigh pain visual analog scale (VAS) score to 1–2/10. In addition, improvement in quadriceps functionality and sleep quality, along with a remarkable reduction in analgesic medicine doses, earned patients high satisfaction. Our patient passed away 6 months later with average VAS severity of 4/10. Spinal dexmedetomidine, caudal-epidural PRF, and lumbar sympathetic nerve block should be added as a therapeutic option to the treatment guidelines for the management of MPS, acquired due to lumbosacral plexopathy.

Keywords

• dexmedetomidine
• epidural pulsed radiofrequency
• lumbar sympathetic nerve block
• malignant psoas syndrome