Neurological emergencies require rapid and accurate decision making and treatment. Inappropriate management in the early stages of disease can have catastrophic consequences for the animal. This chapter reviews acute spinal cord injury, head trauma, status epilepticus and cluster seizures.
20.4Radiographs of the cranial cervical spine of a 2-year-old German Shepherd Dog following a traumatic accident. (a) Lateral radiograph showing a comminuted fracture of C2 (arrowed) as well as evident dorsal subluxation of this vertebra with respect to C1. (b) Ventrodorsal radiograph showing lateral displacement of the C2 vertebra (arrowed) with respect to C1.
20.5The three-compartment theory of assessment of spinal trauma. The dorsal compartment contains the spinous processes and supporting ligamentous structures, in addition to the articular facets, laminae and pedicles. The dorsal longitudinal ligament, the dorsal vertebral body and the dorsal annulus of the disc are contained within the middle compartment. The ventral compartment contains the rest of the vertebral body, the lateral and ventral aspects of the annulus of the disc, the nucleus pulposus and the ventral longitudinal ligament. If two or more compartments are damaged, the fracture is considered unstable, whereas damage to just one compartment may indicate a stable fracture. This does not take into account associated compression of the spinal cord, which may occur with damage to just one of the compartments.
20.6Transverse CT image (bone window) of C1 and C2 in a 16-month-old German Shepherd Dog with neck pain following a traumatic incident. The dens (long arrow) can be seen within the vertebral canal but is displaced laterally. The dorsal lamina of C1 (short arrow) can be identified and is misshapen as a result of a congenital malformation (see Figure 20.7). (Courtesy of F McConnell)
20.7A 3D reconstruction of the case described in Figure 20.6. (a) Dorsal oblique view. C1 is malformed with partial absence of the right neural arch and a misshapen wing. C2 is arrowed. (b) Ventrolateral view. The arrow indicates the ventral surface of C1, which is fused to the occipital bone. (Courtesy of F McConnell)
20.8MR images of the German Shepherd Dog in Figure 20.4. (a) Sagittal T2-weighted MR image of the cervical vertebrae and spinal cord. Although the degree of bone definition is not as good as that seen with CT, the effects of injury (spinal cord and parenchymal compression) can be assessed accurately in three views. The arrow indicates the dorsal arch of C2. (b) Transverse T2-weighted MR image of C2. Note that there is no evident compression of the cord, despite the comminuted nature of the fracture of the vertebra.
20.11Overview of the pathophysiology of head trauma as it relates to the increase in intracranial pressure (ICP), showing the underlying vasculature and biochemical components of secondary injury. CBV = cerebral blood flow; EAA = excitatory amino acids.
20.15Probability of survival of the head trauma patient during the first 48 hours after admission, expressed as a function of the modified Glasgow coma score. (Reproduced from Platt et al., 2001 with permission from the Journal of Veterinary Internal Medicine)
20.16Dorsoventral skull radiograph of a 6-year-old Hungarian Vizla following an incident causing head trauma. Note the large linear calvarial fracture (arrowed). Such images do not provide any useful information about associated parenchymal damage or haematomas. (Courtesy of J Penderis)
20.17(a) Transverse CT image of the skull of a dog crushed by a bite. The fracture of the frontal bone is clearly visible. (b) Transverse CT image of a skull of a dog with a frontal sinus fracture. CT was advantageous in this case as it confirmed that the skull fracture did not affect the inner table of the frontal sinus and therefore had no notable effect on the brain.
20.18Transverse T2-weighted cranial MR image of a 1-year-old Domestic Shorthaired cat that was hit by a car. It is difficult to appreciate the damage to the calvaria on MRI but the associated parenchymal damage is visible (arrowed).