"type I: duplicated dural sac, with midline rigid osseous or cartilaginous spur; usually symptomatic"
"type II: single dural sac, with midline nonrigid fibrous or fibrovascular septum; impairment less marked"
"Type I"
"Type II"
Expected headings
"Type I"
"Type II"
"type I: duplicated dural sac, with midline rigid osseous or cartilaginous spur; usually symptomatic"
"type II: single dural sac, with midline nonrigid fibrous or fibrovascular septum; impairment less marked"