Presumptive acute non-compressive nucleus pulposus extrusion in 11 cats: clinical features, diagnostic imaging findings, treatment and outcome.

Frances E Taylor-Brown,Steven De Decker

doi:10.1177/1098612x15605150

Abstract

Objectives The aim of the study was to describe the clinical features, diagnostic imaging findings, treatment and outcome in cats diagnosed with presumptive acute non-compressive nucleus pulposus extrusion. Methods Medical records and imaging studies of cats diagnosed with presumptive acute non-compressive nucleus pulposus extrusion were retrospectively reviewed. Information on long-term outcome was acquired from patient records and from either owners or referring veterinary surgeons via a telephone questionnaire. Results Eleven cats met the inclusion criteria. All cats had a peracute onset of clinical signs, with eight cats experiencing witnessed (n = 6) or suspected (n = 2) external trauma based on imaging findings. Neuroanatomical localisation included C1-C5 (n = 1), T3-L3 (n = 7) and L4-S3 (n = 3) spinal cord segments. MRI revealed acute non-compressive nucleus pulposus extrusions located at C3-C4 (n = 1), T12-T13 (n = 1), T13-L1 (n = 1), L1-L2 (n = 1), L3-L4 (n = 3), L4-L5 (n = 1) and L5-L6 intervertebral disc spaces (n = 3). Treatment included supportive care and 10 cats were discharged with a median hospitalisation time of 10 days (range 3-26 days). One cat was euthanased during hospitalisation owing to complications unrelated to neurological disease. All cats that presented as non-ambulatory regained an ambulatory status with the median time to ambulation of 17 days (range 6-21 days). Overall, the outcome for cats diagnosed with acute non-compressive nucleus pulposus extrusion was successful, with almost 90% returning to ambulation with urinary and faecal continence. Conclusions and relevance The majority of cats diagnosed with acute non-compressive nucleus pulposus extrusion had good outcomes. Acute non-compressive nucleus pulposus extrusion should be considered as a differential diagnosis for cats presenting with peracute onset of spinal cord dysfunction, particularly if there is a clinical history or evidence of trauma.

Highlights

Acute non-compressive nucleus pulposus extrusion (ANNPE), previously referred to as a traumatic intervertebral disc extrusion (IVDE), high-velocity/low-volume IVDE and type III intervertebral disc extrusion occurs when a healthy and hydrated IVDE is exposed to sudden and excessive force and is typically seen following vigorous exercise or trauma[1,2,3,4]
It has previously been reported that trauma accounts for 14% of cases of feline spinal cord injury,[10] and the occurrence of a vertebral fracture or luxation is generally considered the most important differential diagnosis for cats presenting with a peracute onset of spinal cord dysfunction after a witnessed or suspected traumatic event
There was one patient with a cervical ANNPE. This is consistent with the previous case reports that describe a lumbar and cervical ANNPE4,5. Whilst this contrasts to the findings in dogs, which predominantly have T12-T13 and T13/L1 ANNPE2, it is more consistent with data looking at the location of IVDE, with previous studies suggesting that the mid to caudal lumbar region is more commonly affected in cats[11,12,13]

Summary

Introduction

Acute non-compressive nucleus pulposus extrusion (ANNPE), previously referred to as a traumatic intervertebral disc extrusion (IVDE), high-velocity/low-volume IVDE and type III intervertebral disc extrusion occurs when a healthy and hydrated IVDE is exposed to sudden and excessive force and is typically seen following vigorous exercise or trauma[1,2,3,4]. This type of intervertebral disc extrusion results in spinal cord contusion with minimal or no spinal cord compression[1,2,3]. Magnetic resonance imaging (MRI) can be used to make a presumptive diagnosis with with specific characteristics identified to reach a presumptive ante-mortem diagnosis of ANNPE.[2,3]

Objectives

Results

Discussion

Conclusion