A 4-month-old infant has undergone surgical treatment for meningomyeloencephalocele. At bih, an operation was carried out in the posterior cranial fossa to paially replace brain cerebellar contents to an intracranial position. In investigations for progressive hydrocephalus, it is noted that there is herniation of the cerebellar tonsils through the foramen magnum, and a diagnosis of Arnold-Chiari syndrome is established. This syndrome may also include which of the following?
Abnormal elongation of the medulla and lower cranial nerves may be evident in Arnold-Chiari syndrome. Additional features include fusion of the corpora quadrigemina, leading to a "beaked" tectum; paial or complete absence of the corpus callosum; and microgyria.
Fusion of the frontal lobes
Fusion of the temporal, parietal, and occipital lobes
Abnormal elongation of the medulla and lower cranial nerves
Paial or complete absence of the pituitary gland
Cerebrovascular Diseases