Normal pressure hydrocephalus (NPH) is prevalent in aging patient populations. Despite its clinical relevance, many patients with NPH may not receive adequate treatment. Because of the frequency of Alzheimer's disease in these patients, there could be overlapping pathophysiological mechanisms that are as yet incompletely understood. Cerebral comorbidities seem to have negative effects on therapeutic response to ventriculoperitoneal shunting. In order to avoid unnecessary and unsuccessful surgery in highly vulnerable elderly patients, they have to be taken into consideration in the diagnostic process.