Research Update: Fibrocartilaginous emboli of the spinal cord in cats

These case reports from a university teaching hospital and private referral practice describe the clinical features and diagnostic evaluations of five cats with fibrocartilaginous embolic myelopathy. The cats, ranging in age from 7 to 11 years, were presented for evaluation of acute, asymmetric paresis or paralysis of one or more limbs. All cats were housed indoors and had no history of trauma. Spinal palpation was not painful, and the results of the complete blood counts, serum chemistry profiles, and survey spinal radiographic examinations were normal. One cat underwent myelography, which demonstrated thinning of the dye column (subarachnoid space) without spinal cord compression. In three cases, cerebrospinal fluid (CSF) analysis revealed increased neutrophils.

Three cats were euthanized, and postmortem examinations of two of these cats revealed grossly normal spinal cords. However, histologic examination in the first cat revealed extensive malacia with intravascular fibrocartilaginous emboli of the cranial lumbar spinal cord, and the second cat had fibrocartilaginous emboli of the fourth cervical spinal cord gray matter. In the third cat, magnetic resonance imaging (MRI) revealed intramedullary swelling of the C6-C7 spinal cord. This cat failed to respond to medical therapy and was euthanized five days later; histologic examination confirmed spinal cord degeneration and fibrocartilaginous emboli at C6-C7.

The other two cats had MRI-confirmed spinal cord swelling in the thoracic or lumbar regions and were treated supportively. They recovered two or three weeks later.

COMMENTARY

These case reports highlight an uncommon condition that may be described more frequently as the feline pet population increases and advanced imaging techniques (mri) become common in referral centers. While the cause of fibrocartilaginous emboli remains unclear and treatment is limited to supportive care, increased awareness and diagnosis may help reduce associated morbidity in cats. The key clinical features are acute, nonpainful limb or multiple limb paresis or paralysis in older cats not suffering from trauma. Mri and csf findings help rule out intervertebral disk, neoplastic, or infectious lesions. In some instances, only survey radiography or myelography may be available, and normal results provide a presumptive diagnosis.

Mikszewski JS, Van Winkle TJ, Troxel MT. Fibrocartilaginous embolic myelopathy in five cats.J Am Anim Hosp Assoc 2006;42:226-233.

The information in "Research Updates" was provided by Veterinary Medicine Editorial Advisory Board member Joseph Harari, MS, DVM, DACVS, Veterinary Surgical Specialists, 21 E. Mission Ave., Spokane, WA 99202.

Joseph Harari, MS, DVM, DACVS