An anatomical abnormality affecting the lowermost part of brain, where it joins the spinal cordThe main nerve trunk running down the spinal canal and connecting the individual’s mind and consciousness to the rest ..., at the top of the neck. Various sub-types are described – see under their individual names. The term hindbrain herniaAn alternative term for a Chiari malformation. It is better than the eponymous term because it is in many ways more desc... is sometimes used to incorporate all forms.