Despite the normal mean intracranial pressure in normal pressure hydrocephalus, the cerebral ventricles enlarge. Many hypotheses exist as to why, and these have lately been investigated in simulation. These can be grouped into one of two categories: 1) Tissue damage is caused by a transmantle pressure gradient widening the ventricles mechanically. 2) The overall cerebrospinal fluid dynamics are disturbed resulting from various pathologies. This paper reviews the literature regarding the computational simulation models investigating the development of enlarging ventricles in connection with the onset of hydrocephalus. The models are categorized by the underlying hypothesis and their results are contrasted with clinical findings in the field. Finally, open questions are identified for future modeling approaches.