Postoperative Spinal Subdural Extra-arachnoid Hygroma Because of Trauma: Resolution with Lumbar Puncture: A Case Report.

CASE: A 73-year-old woman, after spinal surgery, presented with symptomatic spinal subdural extra-arachnoid hygroma (SSEH) because of a fall on the third postoperative day. The hygroma was diagnosed by magnetic resonance imaging (MRI). Lumbar puncture was performed under local anesthesia, after which the leg pain disappeared immediately. MRI obtained immediately after puncture and 1 week later confirmed disappearance of the hygroma. CONCLUSION: Although dural transection is mentioned in most of the reports on treatment of symptomatic postoperative SSEH, we were able to treat this entity by epidural puncture. In the absence of paraplegia or cystorectal disturbance, puncture can be an effective and minimally invasive treatment option.

Clinical study of preoperative skeletal muscle mass as a predictor of physical performance recovery following palliative surgery for spinal metastases.

BACKGROUND: Surgical treatment of spinal metastases has been associated with high morbidity and mortality in patients with sarcopenia based on low skeletal muscle mass. We assessed physical performance using the Eastern Cooperative Oncology Group performance status scale and the Barthel Index on the 30th day after palliative surgery for spinal metastases and investigated the effectiveness of surgery according to sarcopenia assessed by skeletal muscle mass. METHODS: We retrospectively analyzed 78 consecutive patients with thoracic and lumbar spinal metastases who underwent palliative surgery. The value of the area of the psoas major muscle at the L3 level normalized by the vertebral area was divided into first, middle, and third tertiles. Clinical variables were compared by tertile. Variables affecting the 30-day good performance status were investigated with univariate and multivariate analyses. RESULTS: The 30-day morbidity rates were 50%, 38.5%, and 15.4% by tertile. The 30-day mortality rate was 2%; all were in the first tertile. Good preoperative performance status scores were seen in 15.4% of first and 50% of third tertile patients. Postoperatively, the performance status improved in all groups, with 30.8%, 65.4%, and 92.3% by tertile. Multivariate regression analysis revealed that a good preoperative performance status (OR: 15.50, 95% CI: 1.610-149.00, P < 0.05) and the value of the area of the psoas major muscle at the L3 level normalized by the vertebral area not in the first tertile (OR: 0.22, 95% CI: 0.06-0.82, P < 0.05) were significant predictors of a good postoperative 30-day performance status. CONCLUSIONS: A good preoperative performance status and exclusion from the first tertile were clinical factors predicting a good postoperative 30-day performance status. In patients with large psoas muscle mass (third tertile), a good 30-day performance status can be expected after surgery, suggesting that surgery in this population should be pursued aggressively.

Retroperitoneal Hematoma Due to Drainage Tube Insertion in Extreme Lateral Interbody Fusion: A Case Report.

CASE: A 73-year-old woman presented with degenerative kyphoscoliosis. Radiographs revealed sagittal and coronal imbalance with lumbar spinal stenosis. Extreme lateral interbody fusion (XLIF) was performed in the first stage of 2-stage surgery, and a closed-suction drainage tube was placed in the retroperitoneal cavity. Postoperatively, there was massive bleeding through the tube. Contrast-enhanced computed tomography revealed lumbar artery injury, which required emergency arterial embolization. CONCLUSION: Placing a drainage tube in the retroperitoneal cavity during XLIF surgery can help detect complications such as intestinal and ureteral injuries, the lumbar artery within the lumbar muscle can be injured during drain placement.

Transsacral Canal Plasty for Decompression of Lumbar Spinal Stenosis in a Patient With Epidural Lipomatosis: A Case Report.

CASE: A 58-year-old man presented with lumbar spinal stenosis due to epidural lipomatosis. He underwent transsacral canal plasty (TSCP), in a manner similar to epidural adhesiolysis, which can be performed under local anesthesia. His leg pain improved dramatically in the year after surgery. Furthermore, magnetic resonance images during this time show neural decompression by reduction of the amount of epidural fat. CONCLUSION: TSCP was found not only to relieve pain but also to achieve neural decompression in this patient with spinal canal stenosis caused by lumbar epidural lipomatosis. This is the first report to demonstrate the usefulness of TSCP for spinal epidural lipomatosis.

Expression of Piezo mRNA is unaffected in a rat model of knee osteoarthritis.

Osteoarthritis of the knee impairs activities of daily living of those affected. Its irreversible degenerative changes to the knee joint induce functional disturbance and unpleasant arthralgia. The pain has inflammatory components and often is manifested with mechanical allodynia and hyperalgesia. Sustained weight bearing and joint movements increase pain sensitivity in knee osteoarthritis. Understanding the mechanisms underlying the mechanical allodynia and hyperalgesia might provide a therapeutical target for pain relief in patients with such symptoms. Piezo channel is a mechanically activated ion channel that may be involved in mechanical transduction in the articular cartilage. Although it has been shown that inflammation potentiates Piezo channel current induced by mechanical stimulation, whether Piezo expression levels are influenced by knee osteoarthritis has remained unknown. We measured Piezo mRNA in knee joints and dorsal root ganglia after establishing a model of knee osteoarthritis in rats using monosodium iodoacetate and found Piezo mRNA level is not upregulated. This finding raises a question as whether and how Piezo channels may be involved in mechanically induced pain in osteoarthritis.

Primary Role of the Amygdala in Spontaneous Inflammatory Pain- Associated Activation of Pain Networks - A Chemogenetic Manganese-Enhanced MRI Approach.

Chronic pain is a major health problem, affecting 10-30% of the population in developed countries. While chronic pain is defined as "a persistent complaint of pain lasting for more than the usual period for recovery," recently accumulated lines of evidence based on human brain imaging have revealed that chronic pain is not simply a sustained state of nociception, but rather an allostatic state established through gradually progressing plastic changes in the central nervous system. To visualize the brain activity associated with spontaneously occurring pain during the shift from acute to chronic pain under anesthetic-free conditions, we used manganese-enhanced magnetic resonance imaging (MEMRI) with a 9.4-T scanner to visualize neural activity-dependent accumulation of manganese in the brains of mice with hind paw inflammation. Time-differential analysis between 2- and 6-h after formalin injection to the left hind paw revealed a significantly increased MEMRI signal in various brain areas, including the right insular cortex, right nucleus accumbens, right globus pallidus, bilateral caudate putamen, right primary/secondary somatosensory cortex, bilateral thalamus, right amygdala, bilateral substantial nigra, and left ventral tegmental area. To analyze the role of the right amygdala in these post-formalin MEMRI signals, we repeatedly inhibited right amygdala neurons during this 2-6-h period using the "designer receptors exclusively activated by designer drugs" (DREADD) technique. Pharmacological activation of inhibitory DREADDs expressed in the right amygdala significantly attenuated MEMRI signals in the bilateral infralimbic cortex, bilateral nucleus accumbens, bilateral caudate putamen, right globus pallidus, bilateral ventral tegmental area, and bilateral substantia nigra, suggesting that the inflammatory pain-associated activation of these structures depends on the activity of the right amygdala and DREADD-expressing adjacent structures. In summary, the combined use of DREADD and MEMRI is a promising approach for revealing regions associated with spontaneous pain-associated brain activities and their causal relationships.