Journal of neurotrauma
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Journal of neurotrauma · May 2022
Restoring hand functions in people with tetraplegia through multi-contact, fascicular and auto-pilot stimulation: a proof-of-concept demonstration.
Two multi-contact epineural electrodes were placed around radial and median nerves of two subjects with high tetraplegia C4, American Spinal Injury Association Impairment Scale (AIS) A, group 0 of the International Classification for Surgery of the Hand in Tetraplegia. The purpose was to study the safety and capability of these electrodes to generate synergistic motor activation and functional movements and to test control interfaces that allow subjects to trigger pre-programmed stimulation sequences. The device consists of a pair of neural cuff electrodes and percutaneous cables with two extracorporeal connection cables inserted during a surgical procedure and maintained for 28 days. ⋯ The success rate in task execution by the electro-stimulated hand exceeded the target of 50% (54% and 51% for patients 1 and 2, respectively). The compliance rate of the control orders in both patients was >90% using motion inertial measurement unit (IMU)-based detection and 100% using electromyography (EMG)-based detection in patient 1. These results support the relevance of neural stimulation of the tetraplegic upper limb with a more selective approach, using multi-contact epineural electrodes with nine and six contact points for the median and radial nerve respectively.
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Journal of neurotrauma · May 2022
Hyperbaric oxygen therapy after mid-cervical spinal contusion injury.
Hyperbaric oxygen (HBO) therapy is frequently used to treat peripheral wounds or decompression sickness. Evidence suggests that HBO therapy can provide neuroprotection and has an anti-inflammatory impact after neurological injury, including spinal cord injury (SCI). Our primary purpose was to conduct a genome-wide screening of mRNA expression changes in the injured spinal cord after HBO therapy. ⋯ In a separate cohort, spinal cord histology was performed to verify whether the HBO treatment impacted neuronal cell counts or inflammatory markers. Compared with untreated rats, there were increased NeuN positive cells in the spinal cord of HBO-treated rats (p = 0.004). We conclude that HBO therapy, initiated shortly after SCI and continued for 10 days, can alter the molecular signature of the lesioned spinal cord in a manner consistent with a neuroprotective impact.
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Journal of neurotrauma · May 2022
ANP and ENaC contribute to spinal cord injury-induced polyuria in mice.
Polyuria is found in patients with spinal cord injury (SCI). However, the underlying cellular and molecular mechanism is unknown. Here, we show that mice had elevated urine for 7 days after T10 contusion. ⋯ An NPR-A inhibitor (A71915) given intravenously eliminated the effects of SCI on ENaC and polyuria. These data together with previous studies suggest that SCI causes polyuria, probably by reducing ENaC activity through elevating ANP and NPR-A. Further investigation of the signal transduction pathways may provide useful information for discovering an efficient drug to treat SCI-induced polyuria.
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Journal of neurotrauma · May 2022
Rostral-caudal effect of cervical magnetic stimulation on the diaphragm motor evoked potential following cervical spinal cord contusion in the rat.
The present study was designed to investigate the rostral-caudal effect of spinal magnetic stimulation on diaphragmatic motor-evoked potentials after cervical spinal cord injury. The diaphragm electromyogram was recorded in rats that received a laminectomy or a left midcervical contusion at the acute (1 day), subchronic (2 weeks), or chronic (8 weeks) injury stages. The center of a figure-eight coil was placed at 30 mm lateral to bregma on the left side, and the effect of magnetic stimulation was evaluated by stimulating the rostral, middle, and caudal cervical regions in spontaneously breathing rats. ⋯ In addition, in contused animals but not uninjured animals, diaphragmatic motor-evoked potential amplitudes were greater at the chronic stage than during earlier injury stages. These results demonstrated that cervical magnetic stimulation can excite the residual phrenic motor circuit to activate the diaphragm in the presence of a significant lesion in the cervical spinal cord. These findings indicate that this non-invasive approach is effective for modulating diaphragmatic excitability after cervical spinal cord injury.
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Journal of neurotrauma · May 2022
The impact of surgical timing on motor level lowering in motor complete traumatic spinal cord injury patients.
Patients with complete traumatic spinal cord injury (tSCI) have a low potential to recover ambulation. Motor level recovery, adjacent to the level of injury, could influence functional independency. This study addresses whether surgical timing influences motor level recovery in patients with motor complete (American Spinal Injury Association [ASIA] Impairment Scale A [AIS A]) and motor incomplete (AIS B) tSCI. ⋯ The presence of sacral sparing (AIS B) at initial examination, and cervical level of the tSCI were associated with ≥1 motor level lowering. In addition, AO Spine C-type injuries were negatively associated with any type of neurological recovery, except motor level lowering. Although sensorimotor complete injuries as well as thoracolumbar injuries negatively influence neurological recovery, early surgical decompression (< 24 h) appears independently associated with enhanced neurological recovery in patients with traumatic spinal cord injury despite level and severity of injury.