Intraaxial Spinal Cord Hemorrhage Secondary to Atlantoaxial Subluxation in a Dog

Abstract

A 1-year-old, 3.5-kg, spayed female, toy poodle was presented for acute-onset tetraplegia and neck pain. Neuroanatomical diagnosis was consistent with a first through fifth cervical (C(1) through C(5)) spinal cord lesion. Radiographs of the cervical vertebral column revealed atlantoaxial (AA) subluxation. Magnetic resonance imaging revealed abnormalities consistent with intraaxial spinal cord hemorrhage at the level of the AA articulation. The dog was treated with external coaptation. After 8 days, the dog regained voluntary motor function in all four limbs. Surgical stabilization was pursued. Postoperatively, the dog regained the ability to ambulate. This report details the imaging findings and management of a dog with intraaxial spinal cord hemorrhage secondary to AA subluxation.

Computed tomography, magnetic resonance imaging and a novel surgical approach of atlanto-axial instability with incongruence in dogs

“…In fact, considering literature data regarding the treatment of AA instability in toy breeds, conservative options and several surgical stabilisation techniques are described [1,2,10,12,13,15,19,26]. Standard surgical treatment consists of ventral arthrodesis with cross pinning, transarticular lag screw fixation or vertebral plating [1,12,19,21,24].…”

“…Irrespective of the aetiopathogenesis, AA instability causes acute and/or chronic spinal cord compression [1,2]. Secondary lesions typically develop in affected individuals including spinal cord compression, contusions or haemorrhage which can predispose to hydromyelia, focal or diffuse syringohydromyelia and gliosis [9,15,17,26]. The principal radiographic sign of AA subluxation is enlargement of the space between the tip of the spinous process of the axis and the dorsal arch of the atlas [26] on laterolateral radiography.…”

Acute non-ambulatory tetraparesis with absence of the dens in two large breed dogs: case reports with a radiographic study of relatives

“…Presence or absence of deep pain sensation and findings on magnetic resonance (MR) images are significant information in prognostic evaluation of dogs with an acute-onset of tetraplegia/tetraparesis secondary to atlantoaxial subluxation [16,34,35]. Nevertheless, it may be difficult to make a certain prognosis and thereby hard to recommend euthanasia versus surgical treatment and rehabilitation of such dogs.…”

“…In a prospective study including MR images of 100 human patients with a traumatic cervical spinal cord injury, Miyanji et al [37] found that hemorrhage, swelling and maximum compression of the spinal cord were associated with a poor prognosis for neurologic recovery. In a one-year-old toy poodle dog presented for acute-onset tetraplegia and given a guarded prognosis for full neurological recovery, Kent et al [34] chose conservative treatment with external coaptation for eight days before re-examining the dog and evaluating the prognosis. In the present study, both dogs showed irreversible lesions in the atlantoaxial region of the spinal cord consisting of necrosis, loss of neural parenchyma and infiltration of gitter cells.…”

What Is Your Neurologic Diagnosis?

“…[3][4][5] Equally, SIEH and hematomyelia are 2 rare clinical entities in veterinary medicine. 13,14 Intramedullary hemorrhage may develop in dogs with suspected spontaneous bleeding, arteriovenous malformation, or myelomalacia. 13,14 Intramedullary hemorrhage may develop in dogs with suspected spontaneous bleeding, arteriovenous malformation, or myelomalacia.…”