AIMTo explore an accurate neurophysiological technique that demonstrates small functional differences after spinal cord injury and assesses therapeutic interventions.

METHODSA modified weight drop (WD) technique was used at T8 in rats to build graded spinal cord injury model. Rubrospinal MEPs were recorded at T13 epidurally to monitor spinal cord function in end week 4 after graded spinal cord injury. The efficacy of this techniques to monitor spinal cord function was compared to BBB locomotor rating scale and histologic evaluation.

RESULTSA characteristic peak complex of rubrospinal MEPs in sham-operated group consisted of 5-7 positive waves and 4-5 negative waves emerging after red nucleus stimulation. The summed peak to peak amplitude (for practical reasons, called peak amplitude) was (195.25 +/- 34.35) microV and decreased following spinal cord injury. The latency of the first peak (positive wave) was (1.57 +/- 0.15) ms and prolonged following spinal cord injury. Significant Linear relationship existed between the peak amplitude and the BBB scores (r = 0.79) and between the peak amplitude and the residual matter obtained from the section with maximum tissue damage( r = 0.87). The close relationship between the latency of the first peak and the BBB scores (r = -0.88) and between the latency of the first peak and residual matter (r = -0.86) were observed.

CONCLUSIONAmplitudes and latencies of rubrospinal MEPs are very valuable parameters to demonstrate small function differences. Rubrospinal MEPs can be used as a reliable measure for motor function prognosis after spinal cord injury.

Animals ; Evoked Potentials, Motor ; Male ; Rats ; Rats, Wistar ; Red Nucleus ; physiopathology ; Spinal Cord Injuries ; pathology ; physiopathology

Spinal cord injury (SCI) is frequently companied by necrosis and apoptosis of oligodendrocytes (OLs), which contributes to demyelination of myelinated nerve fibers and their electrophysiological defects. This pathological demyelination often results in sensory or motor deficits. Here, we first focus on the microenvironment changes after SCI that cause OLs' death, then discuss the major mechanism of endogenous oligodendrocytogenesis and axonal remyelination, and finally summarize current therapies targeting OLs protection and replacement.
Animals ; Apoptosis ; physiology ; Cell Death ; physiology ; Humans ; Necrosis ; pathology ; Nerve Fibers, Myelinated ; pathology ; Nerve Regeneration ; physiology ; Oligodendroglia ; pathology ; Spinal Cord ; physiopathology ; Spinal Cord Injuries ; pathology ; physiopathology ; therapy

Adult ; Brain ; pathology ; physiology ; Humans ; Magnetic Resonance Imaging ; Male ; Spinal Cord Injuries ; pathology ; physiopathology

OBJECTIVETo explore whether X-irradiation can enhance the functional and structural recovery of the injured spinal cord of rats.

METHODSSeventy Sprague-Dawley rats received spinal cord injury by clip compression at the T2 level were randomly divided into two groups. The experimental group received X-irradiation at 14 days after injury, the control group did not receive X-irradiation. The functional tests were performed at day 3, 7, 14, 21, 28, 35, and 42 after irradiation including open field movement, inclined plane and pain withdrawal test. All injured rats were sacrificed at 43 days after injury and the injured spinal cords were taken out for histological tests.

RESULTSSixty-two rats met the experimental requirements among 70 injured rats, 32 rats in experimental group and 30 rats in control group. Statistically significant difference was achieved between two groups in open field movement and inclined plane (P < 0.01), but not for the pain withdrawal test. The edema and necrosis area of injured spinal cords of experimental group were less than those in control group, and the number of axons of experimental group were more than those in control group.

CONCLUSIONSX-irradiation can enhance the functional recovery by improving and restoring structural integrity of the injured spinal cord.

Animals ; Axons ; pathology ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Recovery of Function ; Spinal Cord ; pathology ; physiopathology ; radiation effects ; Spinal Cord Injuries ; pathology ; physiopathology ; radiotherapy

OBJECTIVETo evaluate the effect of local X-irradiation on spinal cord injury by using physiology, kinology, electrophysiology and histology method.

METHODS46 female Sprague-Dawley rats were subjected to spinal cord injury by weight dropping on T(11-12). All animals were divided into 3 groups randomly. One of the animal groups was irradiated with 10 Gy at the lesion site; another was irradiated with 20 Gy, the other without irradiation is regarded as sham-group. The animals were euthanized at different time points at 4 and 12 weeks after irradiation. Spinal cord callus was assessed by using physiology, kinology, and electrophysiology and histology method.

RESULTSIn all the groups, the NF at 14 weeks were found higher than that of 6 weeks. Both 10 Gy irradiated and 20 Gy irradiated groups were higher than those of group at each time point (P < 0.05). The MBP decreased at 14 weeks in irradiated groups (P < 0.05), but increased at 14 weeks in sham-group (P < 0.05), the MBP of irradiated groups was lower than that sham-group at 14 weeks (P < 0.05). The GFAP and Nogo-A at 14 weeks were higher than that in 6 weeks in all the groups (P < 0.05), and there was no statistical significance with physiology, kinology, electrophysiology test in all groups.

CONCLUSIONA self-repair mechanism exists after SCI, which will last at least 14 weeks. Local irradiation promotes the regeneration of spinal cord system after injury to some extent.

Animals ; Disease Models, Animal ; Female ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Spinal Cord ; pathology ; physiopathology ; radiation effects ; Spinal Cord Injuries ; pathology ; physiopathology ; radiotherapy ; X-Rays

Glial scar formed by central nervous system (CNS) injury is the main inhibitory barrier of nerve regeneration. How to promote axonal regeneration after injury,how to accelerate neural network reconstruction and how to improve brain function recovery have become a hot problem to be solved in the field of neuroscience. This article focuses on the recent advances of therapeutic strategies for axonal regeneration.
Animals ; Astrocytes ; pathology ; Brain Injuries ; pathology ; physiopathology ; Cicatrix ; prevention & control ; Humans ; Nerve Regeneration ; Neuroglia ; pathology ; Neuronal Plasticity ; physiology ; Neurons ; physiology ; Proteoglycans ; metabolism ; Spinal Cord Injuries ; pathology ; physiopathology

Adult ; Aged ; Cauda Equina ; pathology ; physiopathology ; Female ; Humans ; Hypesthesia ; pathology ; Male ; Middle Aged ; Neuralgia ; pathology ; physiopathology ; Spinal Cord Injuries ; pathology ; physiopathology

OBJECTIVETo explore the correlation among prevertebral hyperintensity (PVH), sagittal canal diameter on MRI and neurologic function of patients after cervical vertebral hyperextension injury without fracture and dislocation.

METHODSThe clinical data of 100 patients with cervical vertebral hyperextension injury without fracture and dislocation were retrospectively analyzed from September 2010 to December 2013. The patients were divided into PVH group and non-PVH group according to the presence of PVH on T2-weighted magnetic resonance imaging. There were 39 patients in PVH group, including 31 males and 8 females, aged from 21 to 83 years old with an average of (58.10 ± 14.78) years; and the other 69 patients in non-PVH group, including 49 males and 12 females, aged from 32 to 77 years old with an average of (55.05 ± 10.36) years. The sagittal disc level canal diameters of subaxial cervical spine were measured on mid-sagittal magnetic resonance imaging. The age, sex, cause of injury, and the segments of spinal stenosis were recorded. American Spinal Injury Association (ASIA) impairment scale and motor score were used to evaluate the neurological status.

RESULTSThe ASIA motor score of the group with PVH was 52.56 ± 31.97 while the ASIA motor score was 67.70 ± 22.83 in non-PVH group (P = 0.013). More patients with intramedullary hyperintensity signal on MRI were observed in the PVH group than in non-PVH group (P = 0.006). There was a significant positive correlation between ASIA motor score and sagittal disc level canal diameter of injury segment (P = 0.003). The neurological status was worse in patients with multi-level sagittal canal diameters below 8 mm.

CONCLUSIONThe PVH and the disc-level canal sagittal diameter of the injury segment are associated with neurological status. The patients with multi-level sagittal canal stenosis are vulnerable to severe cervical spinal cord injury.

Adult ; Aged ; Aged, 80 and over ; Cervical Vertebrae ; injuries ; Female ; Humans ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Retrospective Studies ; Spinal Canal ; pathology ; Spinal Cord Injuries ; pathology ; physiopathology

Adult ; Aged ; Cervical Vertebrae ; pathology ; physiopathology ; surgery ; Female ; Fracture Fixation, Internal ; adverse effects ; Humans ; Intervertebral Disc Displacement ; pathology ; Male ; Middle Aged ; Radiculopathy ; Spinal Cord Diseases ; etiology ; Spinal Cord Injuries ; pathology ; Spinal Diseases ; pathology ; Spinal Osteophytosis ; etiology ; Transplants ; adverse effects

AIMStudy on the relationship between the degraded spinal cord injuries and the changes of the motor evoked potentials (MEP) to prove the diagnosis and prognosis value of MEP.

METHODSAfter injury at T8-T9 cord using modified Allen's weight-drop method, 27 male SD rats were divided randomly into control group (n = 5), group A (50 gcf, n = 8), group B (70 gcf, n = 8) and group C (100 gcf, n = 6). MEPs elicited by monopolar transcortical stimulation were recorded continuously before injury, just after injury, 15 minutes, 1 hour, 3 hours and 6 hours after injury. The rate of the size of the bleeding or necrosis area to the total cord was also calculated.

RESULTSMEP had no significant change in the control group. The amplitude of MEP's early components in group A or group B decreased or even obliterated after SCI, and then partially recovered, while the late components were lost without any recovery signals. All animals in group C showed no MEP waves excepting 2 rats had recovery signals. The size of the cord injuries area increased according to the dropping force and was correlated significantly with the amplitude of the largest peaks of scMEP 1 hour after SCI (r = -0.821).

CONCLUSIONThe scMEP changes after SCI are correlated with the injury forces and the pathological changes in the cord, which indicates that scMEP can be used as an objective index for the cord functional monitoring.

Animals ; Electric Stimulation ; Evoked Potentials, Motor ; physiology ; Male ; Rats ; Rats, Sprague-Dawley ; Spinal Cord Injuries ; pathology ; physiopathology