Purpose: We reviewed our experience to see if the widely accepted ratio of oral to intrathecal morphine was appropriate. Methods: Eight patients who underwent intrathecal analgesia between 2009 and 2019 were retrospectively reviewed. The opioid dose before the start of intrathecal analgesia was converted to oral morphine. Results: Intrathecal analgesia was performed with morphine and bupivacaine. The ratio of oral:intrathecal was 10:1, 35:1, 44.6:1, 50:1, 62.5:1, 114.6:1, 125:1, 125:1. It took 2 to 14 days for the intrathecal morphine dose to stabilize. There were no cases that the morphine must reduce after stabilization, and there were cases that the morphine dose needed to be increased further. Conclusion: The ratio of oral to intrathecal morphine has been reported to be 200:1 or 300:1, however, this may not provide sufficient analgesia. Each patient needs to be adjusted individually.

We report a case of herpes zoster-associated pain in the third branch of the trigeminal nerve caused by Ramsay Hunt syndrome that was successfully treated with pulsed radiofrequency to the Gasser ganglion. A 51-year-old man was diagnosed as having herpes zoster in the third branch of the trigeminal nerve. He had right facial paralysis and dysgeusia from onset, and was diagnosed as having Ramsay Hunt syndrome. After undergoing ultrasound-guided superficial cervical plexus block and mental nerve block, his pain level was reduced by half but remained, and discomfort and pain in the right inner ear and dysgeusia persisted. Seven days subsequently, Gasserian ganglion block was performed, and his facial paralysis, discomfort and pain in the right inner ear, and dysgeusia owing to Ramsay Hunt syndrome were improved. Our case indicates that Gasserian ganglion block is effective for patients with herpes zoster-associated pain extending over multiple nerve areas of the face, which is refractory to medical treatment and peripheral nerve blockade.

We experienced a case in which a complex regional pain syndrome (CRPS) patient developed new CRPS after intravenous catheterization and it took 8 days for intervene due to delays in information sharing. The patient was a 29-year-old woman diagnosed with type II CRPS of the left upper limb. She had a history of asthma. Three years after the first consultation, she was secured the eighth intravenous access to the right dorsum of hand for the purpose of administering steroids because of severe asthma attack. She complained of severe pain at the puncture site, followed by edema and allodynia. On day 12 after puncture, she was diagnosed with CRPS of the right upper limb. The main cause of delays in intervention was low awareness of the risk of developing CRPS among medical staff. In order to expedite intervention, we shared information on CRPS patients with all medical staff on the electronic medical record, and alerted them when performing invasive medical procedures.

Nocturnal leg cramps are happened commonly in calves. They often recur and have difficulty to be treated. While the effectiveness of the medial branch of the deep fibular nerve block is reported for leg cramps, it has not been reported in pain clinic diseases. In the current study, four pain clinic cases were evaluated. In three cases, the cramps occurred in the gastrocnemius muscle, and another in the tibialis anterior muscle. The duration was about two weeks or more. Although the mechanism of the medial branch of the deep fibular nerve block is unclear, it could be a very minimally invasive, convenient and satisfactory treatment for nocturnal leg cramps.

Most of the population has been vaccinated against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Here we describe the case of a 17-years-old girl who developed breakthrough pain in the left forearm following SARS-CoV-2 vaccination and was diagnosed with complex regional pain syndrome (CRPS) type II. The patient received several treatments including brachial plexus block, stellate ganglion block, xenon light irradiation, and Japanese Kampo medicine. At 22 weeks after the vaccination, the patient achieved a visual analog scale score of 0 for both pain at rest and breakthrough pain, illustrating the efficacy of the combined treatment for CRPS type II.

Spinal cord electrical stimulation (SCS) is effective for intractable neuropathic pain and ischemic pain, but there has been no report of effectiveness for leg muscle cramps. We report a case in which SCS was effective for painful leg muscle cramps. A 46-year-old woman had leg pain due to lumbar spinal stenosis. Posterior decompression and fusion surgery were performed, but her pain did not improve and she developed leg muscle cramps. Her symptoms were resistant to medication, but were temporarily improved by epidural block and nerve loot block. Therefore, we planned SCS to improve her symptoms. SCS decreased the intensity of pain and disappeared muscle cramps. SCS may be an option for the therapy of intractable muscle cramps due to lumbar spinal stenosis.

We report a difficult diagnostic case of secondary trigeminal neuralgia due to idiopathic orbital inflammation. A 65-year-old man presented right facial pain in the first division area of the trigeminal nerve. Along with increasing facial pain, right eye pain and diplopia appeared. Ophthalmalgia was cured with steroid eye drops, but facial pain and diplopia persisted. CT findings revealed a mass in the right ethmoid sinus and orbit with bone destruction. These findings suspected malignant sinus disease and surgery was performed. Histologic examination showed no evidence of atypical cells, granulomas, or fungi, just infiltrations of inflammatory cells. Despite postoperative treatment with antibiotics for sinusitis, facial pain and diplopia suddenly worsened. The possibility of idiopathic orbital inflammation emerged. After starting oral prednisolone, symptoms promptly improved. In this case, many atypical findings made the diagnosis difficult. Idiopathic orbital inflammation has been reported to rarely involve the paranasal sinuses and should be considered as a differential diagnosis.