History
A 1.5-year-old spayed female English Bulldog was referred for further evaluation because of a 2-week history of paraparesis. Abnormal neurologic findings included ambulatory paraparesis, which was more pronounced on the right; decreased postural reactions in the pelvic limbs; and hyperpathia on manipulation of the midlumbar region of the vertebral column, consistent with a lesion in the lumbar region. Pertinent laboratory abnormalities at the time of admission included mild neutrophilia (10,890 cells/μL; reference range, 2,060 to 10,600 cells/μL), lymphopenia (605 cells/μL; reference range, 690 to 4,500 cells/μL), and hyperglobulinemia (4.5 g/dL; reference range, 1.6 to 3.6 g/dL). Radiographs of the lumbosacral portion of the vertebral column were obtained (Figure 1).
Lateral (A) and ventrodorsal (B) radiographic views of the lumbosacral portion of the vertebral column of a 1.5-year-old spayed female English Bulldog evaluated because of a 2-week history of paraparesis.
Citation: Journal of the American Veterinary Medical Association 237, 11; 10.2460/javma.237.11.1245
Determine whether additional imaging studies are required, or make your diagnosis from Figure 1—then turn the page →
Diagnostic Imaging Findings and Interpretation
Lysis of the caudal aspect of the body of L5 and dorsal aspect of the caudal endplate is evident (Figure 2). The cranial endplate of L6 is irregular and concave, also consistent with lysis. Portions of the body and pedicles of L5 and the cranial aspect of the body of L6 have increased opacity. Mildly irregular periosteal new bone is visible extending from L5 through L6. These changes are most consistent with diskospondylitis or late-stage vertebral physitis.
Same radiographic images as in Figure 1. A—Notice the areas of lysis at the caudal aspect of L5 and cranial aspect of L6 and the separation of the caudal endplate of L5 from the vertebral body (top arrow). Portions of the body of L5 and pedicles and the cranial aspect of the body of L6 have increased opacity. There is periosteal new bone extending from most of the ventral aspect of L5 through the middle portion of L6 (bottom arrows). B—Notice the increased opacity of L5, vertebral end-plate lysis bordering the L5-6 disk space, and periosteal new bone extending from the lateral aspects of L5 through the cranial aspect of L6 (arrows).
Citation: Journal of the American Veterinary Medical Association 237, 11; 10.2460/javma.237.11.1245
Magnetic resonance (MR) imaging of the thoracic and lumbosacral regions was performed (Figure 3). On the pre-contrast MR image, the bodies of L5 and L6 have markedly low signal intensities; tissue with a low signal intensity extends dorsally into the spinal canal as well as ventrally to the vertebrae. The abnormal tissues extending into the ventral aspect of the spinal canal are displacing the filum terminale and spinal nerves of the cauda equina dorsally. On the postcontrast MR image, marked contrast enhancement of L5 and L6 is evident, with abnormal enhancement of epidural spinal canal tissues ventrally from L4 through L6. There is also enhancement of the epidural tissues within the dorsal aspect of the vertebral canal at L5, the central portion of the L5-6 disk, and the adjacent vertebral endplates (most intense at the caudal endplate of L5). In addition to earlier findings, these changes support secondary impingement on the spinal nerves and inflammation of epidural tissues.
Midsagittal T1-weighted precontrast (A) and postcontrast (B; with fat suppression) magnetic resonance images of the lumbosacral region of the vertebral column of the same dog as in Figure 1. A—Notice the low signal intensity of L5 and L6 and the low signal tissue extending dorsally into the spinal canal compressing the filum terminale (arrows). B—Notice the enhancement of the L5 and L6 bodies as well as the ventrally located epidural spinal canal tissues (arrows).
Citation: Journal of the American Veterinary Medical Association 237, 11; 10.2460/javma.237.11.1245
Comments
Fine-needle aspirates from the L5-6 disk space were obtained; a coagulase-positive Staphylococcus organism was cultured. The dog received a 1-week tapering course of dexamethasone and began cephalexin (for a minimum of 6 months) treatment. Complete resolution of neurologic signs was observed at 2 weeks.
Diskospondylitis is an infectious condition of the intervertebral disk, vertebral endplates, and adjacent bone of the vertebral body. Vertebral physitis is characterized by bone lysis initially confined to the caudal physeal zone of affected vertebra, initially sparing the vertebral endplate of the adjacent more caudal vertebra and resulting in more extensive lysis of the caudal endplate of the cranial vertebral segment, with an asymmetric reactive spondylosis. In diskospondylitis, the infection is theorized to extend from the epiphysis more rapidly into the annulus fibrosis, spreading to the endplate of the opposing vertebral segment, resulting in a more symmetric lesion.1
In the dog of this report, the radiographic changes were attributed to either diskospondylitis or late-stage vertebral physitis.1 The use of MR imaging confirmed and characterized the extent of the disease process more completely.
Jimenez MM, O'Callaghan M W. Vertebral physitis: a radiographic diagnosis to be separated from discospondylitis. Vet Radiol Ultrasound 1995; 36:188-195.
