Abstract：
Two 1-day-old full-term female calves from different farms located in the Brazilian state of Rio Grande do Sul were unable to stand due to paresis of the pelvic limbs. Both calves had spina bifida on the spinal lumbar segment and were submitted to euthanasia due to poor prognosis. Postmortem examination revealed cerebellar herniation, caudal displacement of the brainstem, rostral deviation of the cranial nerves, caudal extension of occipital lobes, absence of dorsal lamina of lumbar vertebrae with exposed spinal cord, myelodysplasia, kyphosis, segmental spinal agenesis, renal fusion, muscular atrophy, and arthrogryposis. Histology highlighted myelodysplasia (syringomyelia and diplomyelia) and muscular atrophy. The reverse transcription-polymerase chain reactions for ruminant pestivirus were negative. Based on these lesions, the diagnosis of complex neural tube and skeletal malformations was made. A review of previous publications on calves diagnosed with these malformations, originally called Chiari or Arnold-Chiari malformations, revealed a wide range of nervous system and skeletal lesions. These variations amplified the uncertainty regarding whether all cases represent the same disorder and reinforced the importance of reconfiguring the terminology.
摘要：
来自巴西南里奥格兰德州不同农场的两只1天大的足月母牛由于骨盆四肢瘫痪而无法站立。两只小牛的脊柱腰椎节段均有脊柱裂，并因预后不良而接受安乐死。尸检显示小脑疝,脑干的尾部移位,颅神经的前部偏移,枕叶的尾部延伸，腰椎背层缺失，脊髓外露，骨髓增生异常,后凸畸形,节段性脊髓发育不全,肾融合,肌肉萎缩,和关节病。组织学突出了骨髓增生异常（脊髓空洞症和双髓症）和肌肉萎缩。反刍动物瘟病毒的逆转录聚合酶链反应为阴性。基于这些病变,诊断为复杂神经管和骨骼畸形。回顾以前关于被诊断患有这些畸形的小牛的出版物，最初称为Chiari或Arnold-Chiari畸形，揭示了广泛的神经系统和骨骼损伤。这些差异放大了关于所有病例是否代表相同疾病的不确定性，并加强了重新配置术语的重要性。
