<prompt> Tectal breaking is seen in -Dandy-walker malformationArnold-chiari malformationAqueductal stenosisThird ventricular tumor  <response>: Arnold Chiari malformation :It is herniation of tonsils of cerebellum and medulla oblongata through Foramen magnum into vertebral canal. This results in blockage of exits in the roof of the fourth ventricle foramen of Magendie Luschka causing hydrocephalus. Schwartz mentions that there is a dorsal kink in the cervicomedullary junction and breaking of the Quadrigeminal plate.The quadrigeminal plate is the dorsal part of the midbrain and its another name is Tectum. 