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Clinical trials evaluating early therapies after spinal cord injury (SCI) are challenging because of the absence of a rapid assessment. The aim of this study was to determine whether the severity and level of SCI could be established from a brief neurological assessment capable of being used in an emergency setting. A brief assessment called the SPinal Emergency Evaluation of Deficits (SPEED) was developed and retrospectively evaluated in a cohort of 118 patients with SCI. Foot motor and sensory function was used to indicate injury severity. C3 dermatome sensation, handgrip strength and location of spinal pain were used to indicate the level of injury. With regard to injury severity, a high proportion of patients (94%) with no foot movement at the time of injury were initially diagnosed as motor complete (American Spinal Injury Association Impairment Scale [AIS] grade A-B), whereas all patients with foot movement were identified as motor incomplete (AIS grade C-D). This was reflected by a good correlation (rs = 0.79) and agreement (κ = 0.85) between the SPEED motor score and the acute hospital assessment. With respect to injury level, the majority of cases with cervical SCI (92%) had no or weak handgrip at the time of paramedic assessment, whereas all cases with thoracolumbar SCI had a strong handgrip. The location of spinal pain was also in accordance with the level of spinal injury. The SPEED assessment appears capable of accurately determining the severity and level of cervical SCI in the first hours post-injury. A neurological assessment that can be performed rapidly after injury is important for clinical trials of early therapy and to identify patients most likely to benefit from intervention.

Most cases of human spinal cord injury (SCI) are accompanied by continuing cord compression. Experimentally, compression results in rapid neurological decline over hours, suggesting a rise in intracanal pressure local to the site of injury. The aim of this study was to measure the rise in local intracanal pressure accompanying progressive canal occlusion and to determine the relationship between raised intracanal pressure and neurological outcome. We also aimed to establish whether hypothermia was able to reduce raised intracanal pressure. We demonstrate that, following SCI in F344 rats, local intracanal pressure remains near normal until canal occlusion exceeds 30% of diameter, whereupon a rapid increase in pressure occurs. Intracanal pressure appears to be an important determinant of neurological recovery, with poor long-term behavioural and histological outcomes in animals subject to 8 h of 45% canal occlusion, in which intracanal pressure is significantly elevated. In contrast, good neurological recovery occurs in animals with near normal intracanal pressure (animals undergoing 8 h of 30% canal occlusion or those undergoing immediate decompression). We further demonstrate that hypothermia is an effective therapy to control raised intracanal pressure, rapidly reducing elevated intracanal pressure accompanying critical (45%) canal occlusion to near normal. Overall these data indicate that following SCI only limited canal narrowing is tolerated before local intracanal pressure rapidly rises, inducing a sharp decline in neurological outcome. Raised intracanal pressure can be controlled with hypothermia, which may be a useful therapy to emergently decompress the spinal cord prior to surgical decompression.

Human spinal cord injury (SCI) is usually accompanied by persistent cord compression. Experimental data demonstrate that compression of the traumatized cord results in rapid neurological decline over hours. Undertaking decompression in humans within this time frame has proved impractical, with the time to surgery in studies of urgent decompression averaging between 10 and 24 h. There is, therefore, an important need for a therapy to prevent the neurological deterioration of patients prior to decompressive surgery. The aim of this study was to determine if hypothermia prevents compressive SCI, thereby limiting neurological decline. Rats were subjected to a moderate mid-thoracic SCI and spacers were inserted to compress the spinal cord by 45%. Decompression, by removal of the spacer, was performed immediately, and at 2 or 8 h post-injury. Hypothermia (33 degrees C) was commenced in half the animals at 30 mins post-injury and maintained for 7.5 h, with the other half remaining normothermic (37.3 degrees C). Motor recovery was assessed weekly, and the volume and area of tissue damage determined at the end of the 8-week study period. The results demonstrate that hypothermia significantly improves the behavioral and histological outcome of animals undergoing 8 h of compressive injury (the primary outcome measure). The hypothermia-treated group regained weight-supported locomotion (Basso-Beattie-Bresnahan [BBB] locomotor assessment score 9.5 +/- 0.9), while the normothermic group remained severely paraparetic (BBB score 5.3 +/- 0.6; por= 0.0005). Hypothermia significantly increased the volume and area of healthy tissue in the peri-injury region, as well as the volume of preserved white and grey matter. Overall, the data suggest that hypothermia may be a useful bridging therapy to prevent neurological decline prior to decompressive surgery.

Inflammation in the CNS predominantly involves microglia and macrophages, and is believed to be a significant cause of secondary injury following trauma. This study compares the microglial and macrophage response in the rat brain and spinal cord following discrete mechanical injury to better appreciate the degree to which these cells could contribute to secondary damage in these areas. We find that, 1 week after injury, the microglial and macrophage response is significantly greater in the spinal cord compared to the brain. This is the case for injuries to both gray and white matter. In addition, we observed a greater inflammatory response in white matter compared to gray matter within both the brain and spinal cord. Because activated microglia and macrophages appear to be effectors of secondary damage, a greater degree of inflammation in the spinal cord is likely to result in more extensive secondary damage. Tissue saving strategies utilizing anti-inflammatory treatments may therefore be more useful in traumatic spinal cord than brain injury.