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.

中文翻译：

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马的一次政变对等外伤性脑损伤的计算机断层扫描和磁共振成像

发现一匹 3 岁的纯种母马在田间躺着，怀疑颅骨骨折，被转诊进行进一步评估。神经系统检查发现左侧有强迫性的紧密盘旋，以及所有四肢的远视。母马迟钝，头部轻微向右倾斜，右眼没有威胁反应，右侧面部感觉减弱。站立计算机断层扫描显示背侧颅骨轻微凹陷性骨折和中度轴内中线移位，与创伤性脑损伤 (TBI) 一致。尽管接受了支持性治疗，但母马病情恶化并接受了安乐死。尸检高场磁共振成像显示与骨折部位附近的小脑挫伤一致的结果，大脑尾端和脑干头端出现中度至重度同侧脑水肿，符合政变对等 TBI。脑干病变表明预后不良并支持安乐死的决定。这是第一份关于马政变 contrecoup TBI 的影像学发现的报告。