Degenerative disorders of the cerebellum studied by computerized tomography

A review of our cases as well as of the clinical and radiological literature indicates that, in instances of cerebellar degeneration, certain CT patterns are constant. The most reliable are: 1. Prominence of cerebellar sulci. These are usually not seen normally, except for some of the primary fissures; in atrophy the sulci are easily distinguished. 2. Enlargement of the superior cerebellar cistern and vermian cistern. 3. Enlargement of the cerebellopontine cistern. This cistern, which is also referred to as the cerebellopontine angle cistern and as the lateral recess of the cerebellopontine cisterns, is particularly prominent when the middle cerebellar peduncle is significantly involved. 4. Enlargement of the pre-pontine cistern, which occurs primarily with involvement of the pons. 5. The fourth ventricle may be enlarged, particularly in conditions where the midline cerebellar nuclei are affected. However, the enlargement of the fourth alone does not have to be associated with a pathological process. As previously established with pneumoencephalographic studies, the size of the fourth ventricle can be variable (14). Likewise, enlargement of the cisterna magna is not usually associated with any pathological condition of the cerebellum (15).