Clinical presentation, magnetic resonance imaging features, and outcome in 6 cats with lumbar degenerative intervertebral disc extrusion treated with hemilaminectomy

Abstract

Objective: To describe the clinical presentation, magnetic resonance imaging features, and outcome of cats treated with hemilaminectomy for intervertebral disc extrusion (IVDE). Study design: Short case series.Animals: Six cats. Methods: Medical records were reviewed for signalment, onset, duration, and severity of clinical signs, magnetic resonance imaging features, surgical findings, and clinical outcome with a minimum postoperative follow-up of 4 weeks. Results: Our population included 6 cats with a median age of 8.6 years, consisting predominantly of males (n = 5) and purebred cats (n = 4). An acute onset and short duration of progressive clinical signs of myelopathy was the most common presentation; spinal hyperesthesia was present in 3 cats. A large volume of extradural material was identified by MRI within the lumbar vertebral column of each cat, causing marked spinal cord compression. The most common sites affected were L2-L3 (n = 2) and L6-L7 (n = 2). Follow-up after hemilaminectomy was available in 5 cats: 4 had normal voluntary motor function, and 1 had recurrence of acute paraplegia, compromised nociception, and an extensive T2w hyperintense intramedullary lesion according to MRI. All 4 cats with preoperative urinary incontinence remained incontinent for at least 1 week despite good voluntary motor function of pelvic limbs. Conclusion: Intervertebral disc extrusion was diagnosed by MRI in all 6 cats, most commonly at L2-3 and L6-7. Hemilaminectomy resulted in a good to excellent outcome in 4 of 5 cats. Clinical significance: Feline IVDE can be diagnosed by MRI and carry a good prognosis after surgical decompression, although urinary continence may be delayed despite good pelvic limb voluntary motor function.

Diagnostic Imaging in Intervertebral Disc Disease

“…It can be characterized as dispersed if it is not associated with the affected intervertebral space and spread throughout the epidural space, or non-dispersed if it remains in contact with the affected IVD (94). The MRI features of IVDE in cats are similar to dogs, with the difference that most reported cats have had disc extrusions in the lumbar vertebral column, as opposed to the caudal thoracic and thoracolumbar (T12-13, T13-L1) as seen in small breed dogs (21, [97][98][99].…”

Imaging and histopathologic features of reversible nerve root and peripheral nerve edema secondary to disc herniation in a cat

“…68 Similarly, in humans reversibility of these findings after decompressive surgery has been demonstrated. 69 The overall outcome in IVDH in cats is considered good to excellent after decompressive surgery, 1,35,36,41 but the relevance of concomitant thickening and contrast enhancement of the nerve or nerve root in cats is unknown. The cat described here showed complete neurological recovery and reversibility of nerve and nerve root changes on MRI within 4 months after surgery, suggesting that, similar to IVDH in dogs, thickening and increased contrast uptake of the nerve root may not be an indicator of negative outcome.…”

“…To date, thickening of nerve roots and peripheral nerves in cats has been reported only in neoplastic disorders, most commonly peripheral nerve lymphoma, 17‐25 and rarely in nerve sheath tumors, 11,26‐30 suspected immune‐mediated 13,31 and infectious neuritis, 32 and hyperchylomicronemia 33 . In contrast, nerve root thickening has not been reported in IVDH in cats 34‐41 …”

“…33 In contrast, nerve root thickening has not been reported in IVDH in cats. [34][35][36][37][38][39][40][41] Differentiation of neoplastic and nonneoplastic causes of nerve root thickening by MRI is challenging and may impact clinical decision making. [4][5][6]8 We describe the MRI features of a histologically confirmed peripheral nerve edema secondary to disc extrusion in a cat and its subsequent resolution after surgical treatment.…”

A Study on COMP and CTX-II as Molecular Markers for the Diagnosis of Intervertebral Disc Degeneration

“…The current diagnosis of protrusion of the intervertebral disc at the neck and lower back is based on the consistent findings in medical history, clinical physical examination, and imaging examination; magnetic resonance imaging (MRI) is an optimal noninvasive imaging method for a definite diagnosis [ 2 , 5 ]. Furthermore, in clinical practice, IVDD is graded according to different intervertebral disc signals and heights in MRI findings but does not reflect the staging of IVDD [ 6 ], and no diagnosis could be made at the early stage of the pathological changes because histopathological changes precede the imaging modifications.…”