Blikslager A T, Wilson D A, Constantinescu G M, Miller M A, Corwin L A
Department of Veterinary Medicine and Surgery, College of Veterinary Medicine, University of Missouri, Columbia 65211.
Cornell Vet. 1991 Jan;81(1):67-75.
A 1-year-old half-Arabian colt was referred for evaluation of a cranial cervical abnormality. Physical examination revealed the left wing of the atlas to be more ventral than the right wing. A head tilt, with the pole deviated to the left, was present because of the malpositioned atlas. Neurologic examination identified symmetrical weakness, ataxia, and proprioceptive deficits in all four limbs. Radiographs of the cranial cervical region revealed fusion of the atlas and axis, and deviation of the atlantoaxial joint to the left of the median plane. Euthanasia was elected. Necropsy confirmed the radiographic findings. The atlas was rotated 20 degrees counterclockwise when viewed from the caudal aspect. Multifocal myelomalacia was present in the first and second cervical spinal cord segments. The malformation was believed to be due to a degenerative process or abnormal embryological development.
一匹1岁的半阿拉伯种马驹因颅颈部异常前来接受评估。体格检查发现寰椎左翼比右翼更靠腹侧。由于寰椎位置异常，出现了头部倾斜，头极偏向左侧。神经学检查发现四肢均有对称性无力、共济失调和本体感觉缺陷。颅颈部区域的X线片显示寰椎和枢椎融合，寰枢关节向正中平面左侧偏移。决定实施安乐死。尸检证实了X线检查结果。从尾侧观察时，寰椎逆时针旋转了20度。在颈脊髓第一和第二节段出现多灶性脊髓软化。这种畸形被认为是由于退行性过程或胚胎发育异常所致。
