This is often due to the degenerative disorders of the bone, trauma, or an inflammatory diseases like rheumatoid arthritis.

这种情况通常是由骨的退行性疾病、创伤、类风湿性关节炎等炎性疾病导致的。

This explains why a mutation like the one that causes Huntington's disease, another degenerative neurological disorder, hasn't been eliminated by natural selection.

这就解释了为什么像导致亨廷顿病（另一种退行性神经系统疾病） 的突变还没有被自然选择消除。

Although there is one reported case of the syndrome being the result of a rare degenerative brain disorder, many kids just grow out of it — or find treatment for the underlying infection or migraine.

虽然有一项报告的病例表明，这种综合征是一种罕见的大脑退化性疾病的结果，但许多孩子只是伴随其成长，或是找到了治疗潜在感染或偏头痛的方法。

It can be congenital, meaning that the person is born with it, or acquired, usually due to degenerative disorders like ankylosing spondylitis, where the bones remodel causing intervertebral discs ossification, and the narrowing of the spinal canal.

它可能是先天性的，也就是说患者出生便有这种情况；或是获得性的，通常原因是退行性疾病，如强直性脊柱炎，导致骨重塑，引起椎间盘骨化，进而造成椎管狭窄。