Marília de Albuquerque Bonelli
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Luciana Bignardi de Soares Brisola Casimiro da Costa
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Ronaldo Casimiro da Costa
Abstract
Background: Canine cervical spondylomyelopathy can be separated into osseous and disc-associated (DA-CSM) forms. Our aim was to describe the magnetic resonance imaging (using a high-field scanner) and neurological findings in dogs with DA-CSM and investigate a relationship between these findings.Results: Sixty-three dogs were included: 60/63 (95%) were large breeds, with Doberman Pinschers and males over-represented (70%). Mean and median age at the time of diagnosis was 7.25 and 7.2 years (range 0.41 – 12 years). Chronic signs were noted in 52/63 (83%) dogs, with proprioceptive ataxia the most common. Main site of spinal cord compression was commonly C6-C7 or C5-C6. Thirty-six (57%) dogs had various sites of spinal cord compression. Most dogs younger than 6 years of age had a single affected. Foraminal stenosis was present in 51/63 dogs (81%). T2-weighted hyperintensity was present in 40/63 dogs (63%). Eighty-eight percent of the articular processes showed degenerative changes, which correlated strongly with intervertebral disc degeneration. Ligamentum flavum hypertrophy was seen in 38% of dogs. No correlation was observed between neurologic signs and number of affected sites. A moderate positive correlation was observed between severity of spinal cord compression and neurologic grade (r 0.48; p<0.001).Conclusions: DA-CSM was predominantly observed in older, male Dobermans, with chronic neurologic signs, with compressive lesions located in the caudal cervical vertebral region. Although less common, DA-CSM was also seen in dogs 3 years of age or younger (8%). Single compressive lesions were more common in dogs younger than 6 years of age. Most dogs had concomitant changes (e.g.: ligamentum flavum hypertrophy and foraminal stenosis) that may affect neurologic signs. Most dogs with ligamentum flavum hypertrophy were 6 years or older. A correlation was observed between severity of spinal cord compression and neurologic grade; dogs with more severe spinal cord compression were more likely to have a higher neurologic grade. Dogs with more sites of spinal cord compression did not have more severe neurologic involvement. A very high percentage of dogs had articular process degenerative changes. Possible biomechanical or genetic relationships between degenerative changes in articular processes, ligamentum flavum, and intervertebral discs warrants further investigation.
Spinal Cord Compression by Ligamentum Flavum Hematoma in the Thoracic Spine
