Hyperbaric oxygen therapy after mid-cervical spinal contusion injury

Hyperbaric Oxygen Improves Long-Term Learning and Memory Impairment by Attenuating Neuronal Apoptosis in aMCI Rats

Background

With the aging of the population and the increasing incidence of neurological diseases, amnestic mild cognitive impairment (aMCI) has attracted attention. Hyperbaric oxygen (HBO) has gradually shown the potential in the treatment of aMCI as an emerging treatment method in recent times. This study is to observe the effect of HBO on the long-term learning memory of aMCI rats, and investigate the associated mechanisms.

Methods

Seventy-two male rats (4-month-old) were randomly divided into control (CON) group, aMCI group, HBO group, 24 rats in each group. Each group was randomly divided into CON1, CON7, CON28; aMCI1, aMCI7, aMCI28; HBO1, HBO7, HBO28, 8 rats in each group. The aMCI model rats were established in aMCI and HBO groups. HBO group was treated with HBO for 7 days. The ethological and cytopathology which include Morris water maze (MWM) test, HE staining, TUNEL staining and the expression of Fas/FasL on neuron membrane were conducted to evaluate the effects of HBO on day 1, day 7 and day 28 after HBO treatment.

Results

MWM test showed that the spatial learning and memory ability of the rats decreased in aMCI group, and recovered in HBO group; Compared with aMCI group, the pathological damage of hippocampal nerve cells was alleviated, the number of apoptotic cells was significantly reduced (P < 0.05), and the expression of Fas/FasL on the surface of nerve cell membrane was significantly weakened in HBO group (P < 0.05). There were no significant changes in the spatial learning and memory ability, pathological damage of hippocampal neurons, the number of apoptotic cells, and the changes of Fas/FasL on the surface of hippocampal neurons in HBO1, HBO7, and HBO28 groups (P > 0.05). However, in aMCI1, aMCI7, and aMCI28 groups gradually aggravated (P < 0.05).

Conclusion

1. HBO can improve the long-term learning and memory impairment by attenuating neuronal apoptosis in aMCI rats. 2. Fas/FasL mediated cell receptor death pathway is involved in the apoptosis of hippocampal neurons.

Clinical characteristics analysis of pediatric spinal cord injury without radiological abnormality in China: a retrospective study

PURPOSE

This study aims to analyze the clinical characteristics of Chinese children with spinal cord injury (SCI) without radiographic abnormality (SCIWORA) and explore their contributing factors and mechanisms of occurrence.

METHODS

A retrospective analysis was conducted on the clinical data of pediatric patients diagnosed with SCIWORA from January 2005 to May 2020. Epidemiological, etiological, mechanistic, therapeutic, and outcome aspects were analyzed.

RESULTS

A total of 47 patients with SCIWORA were included in this study, comprising 16 males and 31 females. The age range was 4 to 12 years, with an average age of 7.49 ± 2.04 years, and 70% of the patients were below eight. Sports-related injuries constituted 66%, with 70% attributed to dance backbend practice. Thoracic segment injuries accounted for 77%. In the American Spinal Injury Association (ASIA) classification, the combined proportion of A and B grades accounted for 88%. Conservative treatment was chosen by 98% of the patients, with muscle atrophy, spinal scoliosis, hip joint abnormalities, and urinary system infections being the most common complications.

CONCLUSION

SCIWORA in Chinese children is more prevalent in those under eight years old, with a higher incidence in females than males. Thoracic spinal cord injuries are predominant, dance backbend as a primary contributing factor, and the social environment of "neijuan" is a critical potential inducing factor. Furthermore, the initial severity of the injury plays a decisive role in determining the prognosis of SCIWORA.

Modulatory effect of trans-spinal magnetic intermittent theta burst stimulation on diaphragmatic activity following cervical spinal cord contusion in the rat

BACKGROUND CONTEXT

Magnetic stimulation can noninvasively modulate the neuronal excitability through different stimulatory patterns.

PURPOSE

The present study hypothesized that trans-spinal magnetic stimulation with intermittent theta burst stimulatory pattern can modulate respiratory motor outputs in a pre-clinical rat model of cervical spinal cord injury.

STUDY DESIGN

In vivo animal study.

METHODS

The effect of trans-spinal magnetic intermittent theta burst stimulation on diaphragmatic activity was assessed in adult rats with unilateral cervical spinal cord contusion at 2 weeks postinjury.

RESULTS

The results demonstrated that unilateral cervical spinal cord contusion significantly attenuated the inspiratory activity and motor evoked potential of the diaphragm. Trans-spinal magnetic intermittent theta burst stimulation significantly increased the inspiratory activity of the diaphragm in cervical spinal cord contused rats. Inspiratory bursting was also recruited by trans-spinal magnetic intermittent theta burst stimulation in the rats without diaphragmatic activity after cervical spinal cord injury. In addition, trans-spinal magnetic intermittent theta burst stimulation is associated with increases in oxygen consumption and carbon dioxide production.

CONCLUSIONS

These results suggest that trans-spinal magnetic intermittent theta burst stimulation can induce respiratory neuroplasticity.

CLINICAL SIGNIFICANCE

We propose that trans-spinal theta burst magnetic stimulation may be considered a potential rehabilitative strategy for improving the respiratory activity after cervical spinal cord injury. This will require future clinical study.

Oxygen therapy attenuates neuroinflammation after spinal cord injury

Acute hyperbaric O2 (HBO) therapy after spinal cord injury (SCI) can reduce inflammation and increase neuronal survival. To our knowledge, it is unknown if these benefits of HBO require hyperbaric vs. normobaric hyperoxia. We used a C4 lateralized contusion SCI in adult male and female rats to test the hypothesis that the combination of hyperbaria and 100% O2 (i.e. HBO) more effectively mitigates spinal inflammation and neuronal loss, and enhances respiratory recovery, as compared to normobaric 100% O2. Experimental groups included spinal intact, SCI no O2 therapy, and SCI + 100% O2 delivered at normobaric pressure (1 atmosphere, ATA), or at 2- or 3 ATA. O2 treatments lasted 1-h, commenced within 2-h of SCI, and were repeated for 10 days. The spinal inflammatory response was assessed with transcriptomics (RNAseq) and immunohistochemistry. Gene co-expression network analysis showed that the strong inflammatory response to SCI was dramatically diminished by both hyper- and normobaric O2 therapy. Similarly, both HBO and normobaric O2 treatments reduced the prevalence of immunohistological markers for astrocytes (glial fibrillary acidic protein) and microglia (ionized calcium binding adaptor molecule) in the injured spinal cord. However, HBO treatment also had unique impacts not detected in the normobaric group including upregulation of an anti-inflammatory cytokine (interleukin-4) in the plasma, and larger inspiratory tidal volumes at 10-days (whole body-plethysmography measurements). We conclude that normobaric O2 treatment can reduce the spinal inflammatory response after SCI, but pressured O2 (i.e., HBO) provides further benefit.