Chronic post-traumatic intramedullary lesions in dogs, a translational model

Abstract

ObjectivesPost-traumatic intramedullary myelopathies and cavitations are well described lesions following spinal cord injury (SCI) in humans and have been described in histopathological evaluations in dogs. Human intramedullary myelopathies/cavitations are associated with severe initial SCI and deterioration of clinical signs. Canine intervertebral disc extrusions share similarities with SCI in humans. In this descriptive study, magnetic resonance imaging (MRI) findings in spinal cords of dogs suffering from chronic post-traumatic myelopathies, including cavitations, are elucidated. An additional aim of the study was to compare diagnostic imaging and histopathological findings and identify similarities between human and canine chronic post-traumatic spinal cord lesions.MethodsThirty-seven dogs with thoracolumbar SCI and one or more 3Tesla MRI investigations more than 3 weeks after SCI were included. Extent of intramedullary lesions and particularly cavitations were evaluated and measured in sagittal and transverse MRI planes. These data were compared with clinical data.ResultsA total of 91.9% of study patients developed chronic intramedullary lesions, and 86.5% developed intramedullary cavitations. Paraplegia without deep pain perception at initial examination was significantly associated with longer chronic myelopathies/cavitations (P = 0.002/P = 0.008), and with larger maximal cross-sectional area (mCSA) of the lesions (P = 0.041/0.005). In addition, a non-ambulatory status after decompressive surgery was also associated with the development of longer intramedullary lesions/cavitations (P<0.001) and larger lesion mCSA (P<0.001/P = 0.012). All dogs with negative outcome developed myelopathies/cavitations. In the group of 21 dogs with positive outcome, 3 did not develop any myelopathies, and 5 did not develop cavitations.ConclusionsDevelopment of chronic intramedullary lesions/cavitations are common findings in canine SCI. Extensive chronic intramedullary lesions/cavitations reflect a severe initial SCI and negative clinical outcome. This supports the hypothesis that chronic spinal cord changes following SCI in humans share similarities with canine chronic spinal cord changes after spontaneous intervertebral disc extrusion.

Improved Healing after the Co-Transplantation of HO-1 and BDNF Overexpressed Mesenchymal Stem Cells in the Subacute Spinal Cord Injury of Dogs

“…The injury pattern of the spinal cord in dogs, such as naturally occurring intervertebral disk herniation (IVDH), has a close resemblance with IVDH in humans. Magnetic resonance imaging showed similar post-traumatic myelopathies, such as cystic cavities, spinal cord atrophy, and syringomyelia in dogs and humans due to IVDH 51 . We used balloon compression SCI model in dogs, which closely mimic the contusion or compression caused by IVDH in dogs and humans 52 .…”

Short‐ and long‐term outcome and magnetic resonance imaging findings after surgical treatment of thoracolumbar spinal arachnoid diverticula in 25 Pugs

“…Deactivation of compensatory mechanisms and nonreversible signs of neurological dysfunction in animals with chronic compressive lesions are described in the experimental studies, in 1 of them, chronic nonprogressive spinal cord compression causing ongoing deterioration of signs and progressive loss of motor neurons observed for a 25‐week period after induction of compression . Increase and formation of intramedullary lesions is known in chronic cases after acute spinal cord injury, it is in question if similar changes could develop after chronic compression . To determine the relevance of increased T2W hyperintensity on postoperative MRI, a comparison with imaging results of Pugs without clinical deterioration would be necessary.…”

“…Although intramedullary lesion is likely to progress in surgical cases where SAD was not appropriately excised, explanation of this observation is not 19,31 Increase and formation of intramedullary lesions is known in chronic cases after acute spinal cord injury, it is in question if similar changes could develop after chronic compression. 32 To determine the relevance of increased T2W hyperintensity on postoperative MRI, a comparison with imaging results of Pugs without clinical deterioration would be necessary.…”

Treatment of posttraumatic syringomyelia: evidence from a systematic review

“…Observational designs were applied in all studies. One study used an experimental design investigating the effect of shunt insertion on syrinx length and size in an animal model [8] and an observational study in dogs [3]. Both were excluded because they were not including human subjects.…”