All of the following are true about Arnold-Chiari malformation except:
A
Type I Chiari malformation is displacement of cerebellar tonsil into cervical canal
B
Type II Chiari malformation is associated with syringomyelia of cervical canal
C
Type II Chiari malformation is characterized by elongation of the 4th ventricle and kinking of the brainstem, with displacement of the inferior vermis, pons, and medulla into the cervical canal
D
Type I Chiari malformation is not associated with hydrocephalus