Neoplasms developing in the pontocerebellar angle are presumably accompanied by manifestations referable to the cerebellum, pons and certain cranial nerves. If the tumor originates in the cerebellum, cerebellar symptoms will appear first. If the tumor originates in the eighth nerve, the most frequently involved among the cranial nerves, vestibular or auditory symptoms will appear first. Besides the eighth, also the seventh, sixth and fifth nerves are affected quite frequently.
In any given case, in which a pontocerebellar involvement is suggestive, a systematic investigation with regard to the encroachment on the above mentioned portions of the central nervous system is usually made and a diagnosis is arrived at without great difficulty. In some cases, however, the stituation is not so easy and only a repeated examination may render assistance. A third group of cases may be so baffling for want of gross or slight symptoms that no opinion can be rendered