Humans, primates, and rodents with cervical spinal cord injury (SCI) show permanent sensorimotor dysfunction of the upper/forelimb as consequence of axonal damage and local neuronal death. This work aimed at characterizing a model of cervical SCI in domestic pigs in which hemisection with excision of 1 cm of spinal cord was performed to reproduce the loss of neural tissue observed in human neuropathology. Posture and motor control were assessed over 3 months by scales and kinematics of treadmill locomotion. Histological measurements included lesion length, atrophy of the adjacent spinal cord segments, and neuronal death. In some animals, the retrograde neural tracer aminostilbamidine was injected in segments caudal to the lesion to visualize propriospinal projection neurons. Neuronal loss extended for 4–6 mm from the lesion borders and was more severe in the ipsilateral, caudal spinal cord stump. Axonal Wallerian degeneration was observed caudally and rostrally, associated with marked atrophy of the white matter in the spinal cord segments adjacent to the lesion. The pigs showed chronic monoplegia or severe monoparesis of the foreleg ipsilateral to the lesion, whereas the trunk and the other legs had postural and motor impairments that substantially improved during the first month post-lesion. Adaptations of the walking cycle such as those reported for rats and humans ameliorated the negative impact of focal neurological deficits on locomotor performance. These results provide a baseline of behavior and histology in a porcine model of cervical spinal cord hemisection that can be used for translational research in SCI therapeutics.

Diseño de Estudio: Revisión sistemática y metaanálisis. Objetivo: Comparar descompresión medular precoz (< 24 horas) versus tardía (> 24 horas) en la recuperación neurológica de pacientes con lesión medular aguda. Métodos: Se realizó una revisión sistemática según el protocolo de PRISMA para identificar estudios publicados hasta diciembre de 2022. Se incluyeron sólo estudios de cohorte prospectivos y ensayos controlados que comparan la descompresión precoz versus tardía en la recuperación neurológica. Como variables se incluyeron el número de pacientes, nivel lesionado, tiempo de tratamiento, grado de ASIA, recuperación neurológica, uso de corticoesteroides y complicaciones. Para el metaanálisis se desarrolló el gráfico “forest plot”. El riesgo de sesgo de los estudios incluídos se evaluó utilizando la herramienta ROBINS-I22 y Rob223. Resultados: Seis de los siete estudios seleccionados para nuestra revisión fueron incluídos en el metaanálisis, con un total de 1.188 pacientes (592 pacientes en el grupo de descompresión precoz y 596 en el grupo de descompresión tardía), el promedio de seguimiento fue de 8 meses, en 5 estudios utilizaron metilprednisolona, las complicaciones mayormente reportadas fueron los eventos cardiopulmonares tromboembólicos. Cinco estudios mostraron diferencias significativas a favor de la descompresión precoz (diferencia de riesgo 0.10, intervalo de confianza 95% 0.07-0.14, heterogeneidad 46%). El beneficio fue mayor en las lesiones cervicales e incompletas. Conclusiones: Existe evidencia científica para recomendar la descompresión precoz en las primeras 24 horas tras la lesión medular traumática al mejorar la recuperación neurológica final, y debe recomendarse siempre que las condiciones del paciente y el hospital permitan hacerlo con seguridad. Study Design: Systematic review and meta-analysis. Objective: To compare early (24 hours) spinal cord decompression on neurological recovery in patients with acute spinal cord injury. Methods: A systematic review was performed according to the PRISMA protocol to identify studies published up to December 2022. Prospective cohort studies and controlled trials comparing early versus delayed decompression on neurological recovery were included. Variables included number of patients, level of injury, treatment time, ASIA grade, neurological recovery, use of corticosteroids, and complications. For the meta-analysis, the “forest plot” graph was developed. The risk of bias of the included studies was assessed using the ROBINS-I22 and Rob223 tools. Results: Six of the seven studies selected for our review were included in the meta-analysis, with a total of 1,188 patients (592 patients in the early decompression group and 596 in the delayed decompression group), the mean follow-up was 8 months, in 5 studies used methylprednisolone, the most reported complications were thromboembolic cardiopulmonary events. Five studies showed significant differences in favor of early decompression (risk difference 0.10, 95% confidence interval 0.07-0.14, heterogeneity 46%). The benefit was greatest in cervical and incomplete injuries. Conclusion: There is scientific evidence to recommend early decompression in the first 24 hours after traumatic spinal cord injury, as it improves final neurological recovery, and it should be recommended whenever the patient and hospital conditions allow it to be safely done.