Computed tomographic and magnetic resonance imaging of a coup contrecoup traumatic brain injury in a horse

Abstract

Summary A 3‐year‐old Thoroughbred mare found recumbent in the field was referred for further assessment with suspicion of a skull fracture. Neurological examination identified compulsive tight circling to the left, and hypermetria in all four limbs. The mare was obtunded, with a mild head tilt to the right, absent menace response of the right eye and decreased facial sensation on the right. Standing computed tomographic examination revealed a subtle depression fracture of the dorsal calvarium and moderate intra‐axial midline shift consistent with a traumatic brain injury (TBI). Despite supportive treatment, the mare deteriorated and was subjected to euthanasia. Post‐mortem high field magnetic resonance imaging revealed findings consistent with a small cerebral contusion adjacent to the fracture site, and moderate to severe ipsilateral cerebral oedema within the caudal cerebrum and rostral brainstem, consistent with a coup contrecoup TBI. Brainstem lesions indicate a poor prognosis and support the decision for euthanasia. This is the first report of the imaging findings of a coup contrecoup TBI in a horse.

Traumatic brain injuries in horses (coup–contrecoup brain injuries)

“…These are most often used when discussing traumatic brain injury in people and animals. Although traumatic brain injury is uncommon in horses, it often has dire consequences, as described in the article by Morgan et al (2022) in this issue. Most traumatic brain injury results from impact to the head resulting in transient bony deformation leading to various types of fracture to the bones of the calvarium.…”