**2. Epidemiology**

The exact incidence and prevalence of INPH is difficult to determine; however, the incidence of INPH is between 1.8 and 2.2 cases per 1,000,000 individuals [8, 9]. In a door to door survey from two German villages, the 0.41% prevalence of NPH was reported [10]. In patients with dementia, the reported incidence of NPH ranges between 1.6 and 5.4% [11, 12].
