Association of clinical and magnetic resonance imaging findings with outcome in dogs with presumptive acute noncompressive nucleus pulposus extrusion: 42 cases (2000–2007)

Abstract

Clinical and MRI findings can help predict outcome in dogs with acute noncompressive nucleus pulposus extrusions.

Comparison of clinical signs and outcomes between dogs with presumptive ischemic myelopathy and dogs with acute noncompressive nucleus pulposus extrusion

“…[4][5][6]8 Because it is rare to definitively diagnose either condition prior to the death of the patient, both conditions are presumptively diagnosed on the basis of the presence of characteristic clinical findings in conjunction with established MRI criteria. [1][2][3][7][8][9] Although investigators of previous studies 1,2,5,8,10 have reported the characteristic clinical and diagnostic features of ischemic myelopathy and ANNPE separately, to our knowledge, no studies have been performed to compare the clinical signs and outcomes between ischemic myelopathy and ANNPE. Identification of any differences in the clinical findings and outcomes for these 2 conditions could be clinically relevant for attaining a presumptive antemortem diagnosis and developing both short-and long-term prognoses.…”

“…2,8,14,15 Regardless of the condition (ischemic myelopathy or ANNPE), the clinical status of affected dogs typically stabilizes or improves within 24 hours after the onset of neurologic signs without specific treatment. [2][3][4]10 The long-term outcome for both conditions is generally favorable, although the outcome is less favorable for dogs that lose nociception in affected limbs, develop symmetric neurologic deficits, have a lesion affecting the spinal cord intumescences, or have specific MRI findings such as a lesion affecting a large area of the spinal cord. [2][3][4][5] ABBREVIATIONS ANNPE Acute noncompressive nucleus pulposus extrusion CI Confidence interval QOL Quality of life SCS Spinal cord segment…”

“…The long-term outcome was defined as successful if a dog was clinically normal or had mild residual neurologic deficits but was able to maintain normal activities and had complete fecal and urinary continence. 2 Longterm outcome was defined as unsuccessful if a dog was euthanized because of a lack of clinical improvement for at least 2 weeks or had marked neurologic deficits with or without complete urinary or fecal continence at the time of the telephone interview. 2 The same investigator (JF), who was blinded to the presumptive diagnosis of each dog, conducted all interviews.…”

“…A presumptive diagnosis of ischemic myelopathy or ANNPE was made on the basis of MRI criteria as described. 1,2,7 Briefly, criteria for ANNPE included a focal intramedullary hyperintensity overlying an intervertebral disk space on T2-weighted images, reduction in nucleus pulposus volume, mild narrowing of an intervertebral disk space, and the presence of extraneous material or a change in signal intensity relative to that for normal epidural fat within the extradural space. 2 Criteria for ischemic myelopathy included a focal intramedullary hyperintense lesion on T2-weighted images and the absence of the other criteria used to diagnose ANNPE.…”

“…schemic myelopathy and ANNPE are common neurologic emergencies in dogs that have similar clinical signs [1][2][3][4][5][6][7][8][9][10] such as the hyperacute onset of nonprogressive, often markedly asymmetric spinal cord dysfunction without obvious signs of pain. 1,3,5,10 In dogs, ischemic myelopathy is most commonly associated with embolization of fibrocartilaginous material within the spinal cord vasculature that is histologically indistinguishable from nucleus pulposus (ie, fibrocartilaginous embolism) 5,6,[11][12][13] and causes sudden onset of regional ischemia resulting in necrosis of the spinal cord parenchyma.…”