Ischemic spinal cord injury - experimental evidence and evolution of protective measures

Enhanced neural recovery and reduction of secondary damage in spinal cord injury through modulation of oxidative stress and neural response

Spinal cord injury (SCI) presents a critical medical challenge, marked by substantial neural damage and persistent functional deficits. This study investigates the therapeutic potential of cold atmospheric plasma (CAP) for SCI, utilizing a tailored dielectric barrier discharge (DBD) device to conduct comprehensive in vivo and in vitro analyses. The findings show that CAP treatment significantly improves functional recovery after SCI, reduces neuronal apoptosis, lowers inflammation, and increases axonal regeneration. These findings illustrate the efficacy of CAP in fostering a conducive environment for recovery by modulating inflammatory responses, enhancing neuronal survival, and encouraging regenerative processes. The underlying mechanism involves CAP's reactive oxygen species (ROS) reduction, followed by activating antioxidant enzymes. These findings position CAP as a pioneering approach for spinal cord injury (SCI) treatment, presenting opportunities for improved neural recovery and establishing a new paradigm in SCI therapy.

Development and validation of a nomogram for predicting the prognosis in children with spinal cord injuries

AIMS

This research aims to construct and verify an accurate nomogram for forecasting the 3-, 5-, and 7-year outcomes in pediatric patients afflicted with spinal cord injury (SCI).

METHODS

Pediatric patients with SCI from multiple hospitals in China, diagnosed between Jan 2005 and Jan 2020, were incorporated into this research. Half of these patients were arbitrarily chosen for training sets, and the other half were designated for external validation sets. The Cox hazard model was employed to pinpoint potential prognosis determinants related to the American Spinal Injury Association (ASIA) and Functional Independence Assessment (FIM) index. These determinants were then employed to formulate the prognostic nomogram. Subsequently, the bootstrap technique was applied to validate the derived model internally.

RESULTS

In total, 224 children with SCI were considered for the final evaluation, having a median monitoring duration of 68.0 months. The predictive nomogram showcased superior differentiation capabilities, yielding a refined C-index of 0.924 (95% CI: 0.883-0.965) for the training cohort and a C-index of 0.863 (95% CI: 0.735-0.933) for the external verification group. Additionally, when applying the aforementioned model to prognostic predictions as classified by the FIM, it demonstrated a high predictive value with a C-index of 0.908 (95% CI: 0.863-0.953). Moreover, the calibration diagrams indicated a consistent match between the projected and genuine ASIA outcomes across both sets.

CONCLUSION

The crafted and verified prognostic nomogram emerges as a dependable instrument to foresee the 3-, 5-, and 7-year ASIA and FIM outcomes for children suffering from SCI.

Risk Factors for Spinal Cord Injury during Endovascular Repair of Thoracoabdominal Aneurysm: Review of the Literature and Proposal of a Prognostic Score

Despite recent improvements, spinal cord ischemia remains the most feared and dramatic complication following extensive aortic repair. Although endovascular procedures are associated with a lower risk compared with open procedures, this risk is still significant and must be considered. A combined medical and surgical approach may help to optimize the tolerance of the spinal cord to ischemia. The aim of this review is to describe the underlying mechanism involved in spinal cord injury during extensive endovascular aortic repair, to describe the different techniques used to improve spinal cord tolerance to ischemia-including the prophylactic or curative use of spinal drainage-and to propose our algorithm for spinal cord protection and the rational use of spinal drainage.

Near-Infrared Spectroscopy for Spinal Cord Monitoring-A Roadmap to Translational Research in Aortic Medicine

Extensive aortic aneurysms represent a unique challenge necessitating interdisciplinary efforts for safe and effective treatment. Despite various adjunctive neuroprotective strategies, ischemic spinal cord injury remains a devastating complication. This article describes the implementation of collateral network near-infrared spectroscopy as the first noninvasive spinal cord monitoring modality in the setting of extensive open and endovascular aortic repair, from early conceptualization to clinical utilization. Potential capabilities and remaining uncertainties based on current evidence are outlined and discussed.

USP18 overexpression protects against spinal cord ischemia/reperfusion injury via regulating autophagy

BACKGROUND

Spinal cord ischemia-reperfusion injury (SCII) is usually caused by spinal surgery, often leading to severe neurological deficits. The ubiquitin-specific protease 18 (USP18) plays a significant role in neurological diseases.

OBJECTIVE

The present study was designed to assess the effects and mechanisms of USP18 on SCII.

METHODS

By inducing transient aortic occlusion and subsequent reperfusion, a rat model of SCII was successfully established. The Basso-Beattie-Bresnahan scores, the inclined plane test, and hematoxylin and eosin (HE) were used to measure locomotor activity and histological changes in the injured spinal cords. Moreover, the SCII cell model was established using PC12 cells under oxygen-glucose deprivation and reoxygenation (OGD/R). Proinflammatory factors (TNF-α, IL-6, and INF-α) were examined using an ELISA kit. Cell apoptosis was assessed by Annexin V-FITC/PI double-staining and TUNEL assays. Western blot was used to detect the expression levels of proteins related to apoptosis and autophagy.

RESULTS

USP18 expression was decreasedin vivo and in vitro SCII models. The upregulation of USP18 ameliorated hind limbs' motor function, inhibiting inflammation and apoptosis after SCII in rats. USP18 overexpression in vitro may protect PC12 cells from OGD/R-induced damage by modulating inflammatory responses and apoptosis. Moreover, Overexpression of USP18 enhanced autophagy to inhibit cell apoptosis induced by SCII in vivo and in vitro.

CONCLUSIONS

In summary, USP18 overexpression protects against SCII via regulating autophagy.

A long-term survival rat model of spinal cord ischemia injury: Thoracic aortic occlusion combined with aortic bypass circulation

OBJECTIVE

This study aims to investigate the methods for rat spinal cord ischemia injury models with a high long-term survival rate.

METHODS

The rats were divided into three groups: the treatment group, the control group, and the sham operation group. The treatment group had a blocked thoracic aorta (landing zone 3 by Ishimaru - T11) + aortic bypass circulation for 20 min. In the control group, the thoracic aorta at the landing zone 3 was blocked for 20 min. In the sham operation group, only thoracotomy without thoracic aortic occlusion was performed. The mean arterial blood pressure (MABP) of the thoracic aorta and caudal artery before and after thoracic aortic occlusion was monitored intraoperatively. Spinal cord function was monitored by a transcranial motor evoked potential (Tc-MEP) during the operation. Spinal cord function was evaluated by the BBB scale (Basso, Beattie, & Bresnahan locomotor rating scale) scores at multiple postoperative time points. The spinal cord sections of the rats were observed for 7 days after surgery, and the survival curves were analyzed for 28 days after surgery.

RESULTS

After aortic occlusion, the MABP of thoracic aorta decreased to 6% of that before occlusion, and the MABP of caudal artery decreased to 63% of that before occlusion in the treatment group. In the control group, the MABP of both thoracic aorta and caudal artery decreased to 19% of that before occlusion. The Tc-MEP waveform of the treatment group disappeared after 6 min, and that of the control group disappeared after 8 min until the end of surgery. There was no change in the Tc-MEP waveform in the sham operation group. The BBB score of the treatment group decreased more obviously than the control group, and there was a significant difference. There was no decrease in the sham group. Spinal cord sections showed a large number of degeneration and necrosis of neurons, infiltration of inflammatory cells, and proliferation of surrounding glial cells in the treatment group. In the control group, multiple neurons were necrotic. The histology of the sham operation group was normal. The 28-day survival rate of the treatment group was 73.3%, which was higher than the control group (40.0%), and there was a significant difference (p < 0.05).

CONCLUSION

Thoracic aortic occlusion combined with aortic bypass is an effective modeling method for rats with accurate modeling effects and high long-term survival rates.

MicroRNA miR-155 Activity in Mouse Choline Acetyltransferase-Positive Neurons Is Critical for the Rate of Early and Late Paraplegia After Transient Aortic Cross-Clamping

Aortic aneurism open repair surgery can cause spinal cord (SC) injury with 5–15% of patients developing paraparesis or paraplegia. Using a mouse model of transient aortic cross-clamping (ACC), we have previously found that the expression of proinflammatory microRNA miR-155 increases in motoneurons (MNs) and endothelial cells (ECs) of ischemic SCs, and that global miR-155 deletion decreases the percentage of paraplegia by 37.4% at 48-h post-ACC. Here, we investigated the cell-specific contribution of miR-155 in choline acetyltransferase-positive (ChAT+) neurons (that include all MNs of the SC) and ECs to SC injury after ACC. Mice lacking miR-155 in ChAT+ neurons (MN-miR-155-KO mice) developed 24.6% less paraplegia than control mice at 48-h post-ACC. In contrast, mice lacking miR-155 in ECs (ECs-miR-155-KO mice) experienced the same percentage of paraplegia as control mice, despite presenting smaller central cord edema. Unexpectedly, mice overexpressing miR-155 in ChAT+ neurons were less likely than control mice to develop early paraplegia during the first day post-ACC, however they reached the same percentage of paraplegia at 48-h. In addition, all mice overexpressing miR-155 in ECs (ECs-miR-155-KI mice) were paraplegic at 48-h post-ACC. Altogether, our results suggest that miR-155 activity in ChAT+ neurons protects the SC against ischemic injury during the first day post-ACC before becoming deleterious during the second day, which indicates that early and late paraplegias arise from different molecular malfunctions. These results point to the need to develop specific protective therapeutics aimed at inhibiting both the early and late deleterious events after open repair surgery of aortic aneurisms.