Study DesignA retrospective cohort study.PurposeTo investigate the risk factors for postoperative delirium after spine surgery, excluding older age, which has already been established as a strong risk factor.Overview of LiteratureMore than 30 risk factors have been reported for delirium after spine surgery, making it challenging to identify which factors should be prioritized. We hypothesized that risk factors could not be prioritized to date because the factor of older age is very strong and influenced other factors. To eliminate the influence of older age, we performed an age-matched group comparison analysis for the investigation of other risk factors.MethodsThis study involved 532 patients who underwent spine surgery. Two patients of the same age without delirium (delirium negative group) were matched to each patient with delirium (delirium positive group). Differences in suspected risk factors for post-operative delirium between the two groups identified from previous reports were analyzed using univariate analysis. Multivariate analysis was performed for factors that showed a significant difference between the two groups in the univariate analysis.ResultsFifty-nine (11.1%) of 532 patients developed postoperative delirium after spine surgery. Large amounts of intraoperative bleeding, low preoperative concentration of serum Na, high postoperative (day after surgery) serum level of C-reactive protein, low hematocrit level, low concentration of albumin, and high body temperature were detected as significant risk factors in the univariate analysis. Large amounts of intraoperative bleeding remained a risk factor for postoperative delirium in the multivariate analysis.ConclusionsWe should pay attention to and take precautions against the occurrence of postoperative delirium after spine surgery in patients of older age or those who experience severe intraoperative bleeding.

Despite the availability of several modalities of treatment, including surgery, pharmacological agents, and nerve blocks, neuropathic pain is often unresponsive and sometimes progresses to intractable chronic pain. Although exercise therapy is a candidate for treatment of neuropathic pain, the mechanism underlying its efficacy has not been elucidated. To clarify the molecular mechanism for pain relief induced by exercise, we measured Rnf34 and Pacap mRNA levels in the spinal cord dorsal horn of SNL rats, a model of neuropathic pain. SNL model rats exhibited stable mechanical hyperalgesia for at least 6 weeks. When the rats were forced to exercise on a treadmill, mechanical and thermal hyperalgesia were significantly ameliorated compared with the non-exercise group. Accordingly, gene expression level of Rnf34 and Pacap were also significantly altered in the time course analysis after surgery. These results suggest that exercise therapy possibly involves pain relief in SNL rats by suppressing Rnf34 and Pacap expression in the spinal cord.

Background:We report 8 years of follow-up after decompression to treat cervical myelopathy in a patient with Coffin–Lowry syndrome (CLS). CLS is a rare X-linked semidominant syndrome associated with growth and psychomotor retardation, general hypotonia, and skeletal abnormalities. In this patient, the spinal cord was compressed by calcium pyrophosphate crystal deposition in the cervical yellow ligament (YL). To date, only 1 report has described clinical features after surgery for calcified cervical YL in CLS.Methods:A 15-year-old male with tetraplegia secondary to compression of the cervical spinal cord induced by a hypoplastic posterior arch of C1 and calcification of the YL from C2 to C7 was treated surgically with laminectomy from C1 to C7. The patient's history, clinical examination, imaging findings, and treatment are reported. The patient was incapable of speech because of mental retardation, so he could not describe his symptoms. Gait disturbance worsened over the 2 months before admission to our hospital. At admission, the patient could not move his extremities, and tendon reflexes of the upper and lower extremities were significantly increased. Computed tomography of the cervical spine showed YL calcification from C2 to C7. Magnetic resonance imaging showed consecutive compression of the cervical spinal cord. We diagnosed quadriplegia secondary to cervical cord damage and performed emergency surgery.Results:During C1–C7 laminectomy, YL calcification in C2–C7 was observed. The calcification was confirmed as calcium pyrophosphate by crystal analysis. Quadriplegia gradually resolved, and almost disappeared by 2 weeks after the operation. Cervical hyperlordosis was observed in radiographs starting from 1 month after the operation, but it has not progressed and is not associated with any symptoms.Conclusions:The efficacy of decompression continued, and no postoperative complications have occurred during at least 8 years of follow-up.