We investigated the association of chronic low back and neck pain classification based on ICD-11 with pain relief under interdisciplinary pain management. A total of 212 patients with chronic musculoskeletal pain, who visited the Interdisciplinary Pain Center of Keio University Hospital, were categorized into chronic primary musculoskeletal pain (CPMP), chronic secondary musculoskeletal pain, and chronic neuropathic pain (CNP) groups based on ICD-11 and followed-up. We assessed pain intensity using the Brief Pain Inventory (BPI) at the first visit and at 3 months. Improvement of pain was defined as ≥30％ reduction in the BPI. Multivariate logistic regression analysis revealed that CNP were significantly associated with a greater improvement of pain after adjusting for sex, age, duration of pain, level of pain self-efficacy, and treatment options. [odds ratio (CNP/CPMP) (95％ confidence interval); 2.52 (1.25–5.09, p＝0.02)]. We concluded that the ICD-11 code for chronic low back and neck pain is significantly associated with pain treatment outcomes.

Dorsal scapular nerve (DSN) is considered a spinal nerve that affects interscapular pain. Sixteen patients received the DSN block under ultrasound guidance at the posterior scapular regions. All patients had experienced acceptable pain reduction for a few weeks, but all of them required the following block at four weeks after the block. They received the ultrasound-guided pulsed radiofrequency (PRF) to DSN instead of the block. A linear transducer was placed on their neck similar to the posterior approach to the brachial plexus. DSN was located within or around the middle scalene muscle. PRF treatment at 2 Hz with 20-ms burst was administered at 42℃ for 120s using a PRF generator. All participating patients experienced significant pain relief after PRF. Four weeks after PRF, the average numerical rating scale declined from 7.6 to 1.9. At four weeks, 12 patients experienced ＞50％ pain reduction. PRF to DSN might inhibit excitatory nociceptive afferent fibers of DSN and prevent the chronification of the pain.

Ganglion impar block (GIB) is used for treatment of perineal pain. There have been few reports on the long-term efficacy of GIB for cancer pain. We report a case in which perineal pain due to local recurrence of rectal cancer was improved for a period of 15 months by GIBs performed twice. A 53-year-old man had perineal pain due to local recurrence of rectal cancer. We performed neurolytic GIB. Resting and evoked perineal pain was improved by neurolytic GIB. Pain flared up again 9 months later, and we performed a second neurolytic GIB 11 months after the initial block. An analgesic effect persisted for more than 4 months after the second block. GIB can be performed easily and repeatedly and there are few complications. Repeated GIBs for perineal pain due to local recurrence of rectal cancer was considered to be useful for achieving a long-term analgesic effect in our case.

Case: A 68-year-old man underwent cardiac surgery including internal mammary artery dissection using sternal retraction. The day after surgery, he had pain with numbness in the left medial forearm and ulnar side fingers. Two months after surgery, similar symptoms appeared on the right side, gradually, edema and contractures developed in both hands. He was referred to our department 4 months after the surgery. His symptoms, with significant pain and contracture of both hands, met the diagnostic criteria for CRPS. We have performed rehabilitation, pain awareness education, medication, and twelve times ultrasound-guided brachial plexus block (1％ mepivacaine) to control his symptoms. After approximately five months of these treatments, the patient's impeded bilateral upper limbs motion and pain were notably improved. Conclusion: Early multidisciplinary treatment initiation could ameliorate intractable pain syndrome such as complex regional pain syndrome induced by cardiac surgery-related brachial plexus injury.

A 78-year-old man diagnosed as having postherpetic neuralgia in the sacral region complained of urinary retention and defecation disorder 3 days after undergoing the caudal epidural block for the purpose of pain management. We initially assumed that the disorder was associated with the caudal epidural block. However, we concluded that it was associated with herpes zoster in the sacral region because he could urinate soon after caudal epidural block and developed no hematoma in the lumbar epidural space. We should be aware and inform patients that herpes zoster in the sacral region can cause bladder and rectal disorder because it reduces quality of life of patients remarkably.