Thoracic vertebral canal stenosis in cats: clinical features, diagnostic imaging findings, treatment and outcome

Abstract

Objectives The aim of this study was to describe the clinical features, diagnostic imaging findings, treatment and outcome in cats with thoracic vertebral canal stenosis (TVCS). Methods Medical records and imaging studies of cats with TVCS were retrospectively reviewed. Outcome was acquired from patient records and from owners or referring veterinary surgeons via a telephone questionnaire. For each case, breed-, age- and sex-matched controls were identified with CT imaging of the thoracic vertebral column. For each cat, vertebral canal height was determined at three levels for each thoracic vertebra. Vertebral canal heights were compared between control cats of different breeds and between affected and control cats of the same breed. Results Nine TVCS cases were included. British Shorthairs and male neutered cats were over-represented ( P <0.05). Median age at presentation was 9 years. All cats were presented for a chronic, progressive, painful, ambulatory, T3–L3 myelopathy. Five cats were treated conservatively, three surgically and one was euthanased. Two cats treated surgically demonstrated improvement of clinical signs and one demonstrated initial improvement followed by deterioration. Of the conservatively treated cats, three deteriorated and two improved. Compared with controls, affected cats had a lower vertebral canal height at multiple thoracic vertebral levels, being most prominent for British Shorthairs and domestic shorthairs ( P <0.05). Unaffected British Shorthairs had a lower thoracic vertebral canal height at multiple levels than control domestic shorthairs ( P <0.05). Conclusions and relevance TVCS should be considered a differential diagnosis in middle-aged to older cats presenting with a chronic, progressive, painful, T3–L3 myelopathy. The predisposition of British Shorthairs could be explained by a narrower vertebral canal in this breed.

Demographics, clinical findings and diagnoses of cranial thoracic myelopathies (T1–T6 vertebrae) in cats

“…Among these anomalies, the most frequent was vertebral canal stenosis owing to articular process hypertrophy (Figure 3). This condition has been reported in a case report of two cats 3 and a more recent case series of nine cats, 8 with a median age of 9 years reported by the latter study, which is slightly older compared with that in this study (7.3 years). The study by Gillespie and De Decker 8 also reported a higher incidence of thoracic canal stenosis in the cranial thoracic region, more specifically at T3-T4 and T4-T5.…”

“…In a recent study on a population of 43 cats, 5 intervertebral disc herniation was more prevalent in the lumbar vertebral column compared with the thoracolumbar region, with fewer cases of intervertebral disc extrusion cranial to the T11 vertebra, making the area of interest of our study an unusual location for developing disc herniation in cats. 8 With regard to the presentation, most of our cases presented a chronic and progressive clinical history. This is in agreement with the more common conditions diagnosed as, typically, neoplasia, and anomalies can present as chronic and progressive diseases.…”

“…2,3 However, inflammatory, neoplastic, traumatic and vascular disorders are also observed in this region and reported to be more common causes of spinal cord disease in cats in general. 1,2,4 Intervertebral disc herniation is reported to be more common in the lumbar region of cats, 5,6 and reports of disorders affecting the thoracic spinal cord in cats are currently limited to case reports and small case series, such as articular process hypertrophy resulting in vertebral canal stenosis, [7][8][9][10] vertebral hyperostosis, 11 intervertebral disc protrusion (IVDP), 12,13 subarachnoid diverticulum 14 and different types of neoplasia. 15,16 A recent publication described the signalment, clinical presentation and differential diagnoses of cranial thoracic myelopathies (between the T1 and T6 vertebrae) in dogs; 17 however, to the authors' knowledge, there is still a lack of information on myelopathies affecting this region in cats.…”

Minimally invasive spinal surgery in a young cat with vertebral hypertrophy

“… 8 In a more recent study, non-lymphoid neoplasia and IVDD were the most common causes of spinal diseases, and TVCS was the seventh most common. 1 In a case series of TVCS in cats, all cats included in the report were middle-aged or older; 3 hence, TVCS is considered one of the differential diagnoses of middle-aged or older cats presenting with a chronic, progressive, possibly painful T3–L3 myelopathy. Contrary to previous reports, the cat in the present report developed neurological signs caused by TVCS at a young age; thus, TVCS should be included in the differential diagnoses of young cats with progressive, painful T3–L3 myelopathy.…”

“…In retrospective research on TVCS in cats, all cats were over 5 years and the median age was 9 years. 3 TVCS secondary to articular process hypertrophy in two cats and diffuse idiopathic skeletal hyperostosis (DISH) in one cat have been reported. 4 , 5 The age of the cats in these studies was ⩾9 years.…”