The patient was a 64-year-old woman. After radiation therapy for squamous cell carcinoma of the vulva and metastasis of the external iliac lymph nodes, a refractory ulcer appeared in the perineum. After being referred to our department for the purpose of pain control, oxycodone was introduced, and the dose of oxycodone sustained-release tablets was increased to 180 mg/day. Since the ulcer was improved by hyperbaric oxygen treatment and the pain was improved by pregabalin, the dose of oxycodone was carefully reduced. Eight months later, oxycodone 20 mg/day was discontinued. A few days later, she complained of diarrhea, restlessness and insomnia, and she used oxycodone for these symptoms. We explained to her that she had opioid withdrawal and treated with suvorexant and intestinal regulator. Her symptoms improved without re-administration of opioids. The careful dose reduction is necessary to prevent withdrawal symptom in the case of the cessation of the opioid.

Postmastectomy pain syndrome (PMPS) is known as a pathological condition in which pain or numbness persists in the breast, axilla, and inside of the upper arm after breast cancer surgery. The main cause is said to be neuropathic pain due to brachial intercostal neuropathy. PMPS is mainly treated with drug therapy for neuropathic pain. We report two patients who had continued depression after the diagnosis of breast cancer and who also had PMPS symptoms, who had gotten pain relief after treatment at pain clinic.

Introduction: The cardinal symptom of herpes zoster (HZ) is pain. However, in rare cases, it may be accompanied by motor paralysis. Avoidance of movement due to pain delays the detection of paralysis and can be difficult to differentiate from disuse and side effects of drugs even after pain relief. We report a case in which the diagnosis of unilateral paralysis on manual muscle testing (MMT) led us to conclude HZ paralysis was more likely rather than disuse or drug side effects. Case Report: A 90-year-old man who presented with rash and stinging pain in his right thigh was diagnosed with HZ. Because he was unable to move his right leg due to pain at onset, pregabalin was prescribed. Although pain was alleviated after 3 weeks, he failed to walk. MMT revealed decreased motor function of the right hip and knee joints, so he was diagnosed with paralysis of the right L2 to L4 due to HZ. Discussion: In cases of suspected paralysis due to HZ, detailed examinations should be conducted for differentiation with other pathologies causing muscle weakness.

Stiff-person syndrome (SPS) is a rare disorder characterized by painful muscle spasms and rigidity in the whole body. We report a case of SPS due to the presence of positive anti-glycine receptor antibody. Although the cerebral nervous system symptoms such as ptosis and diplopia were improved with steroid pulse therapy, the lower limb pain accompanied with muscle stiffness remained in numerical rating scale (NRS) 6, and was refractory to the treatment of diazepam. Continuous lumbar epidural block was performed at L1–L2 interspace with 0.2％ ropivacaine at a rate of 6 ml/h for 17 days. Thereafter, the lower limb pain decreased to NRS 1 and the muscle spasms disappeared. The patient became able to walk after the addition of intravenous immunoglobulin therapy.