Demência due to normal pressure hydrocephalus results from excess accumulation of cerebrospinal fluid in the brain as a result of idiopathic, non-obstructive causes but can also be secondary to haemorrhage, infection or inflammation. Progression is gradual but intervention (e.g., shunt) may result in improvement of symptoms, especially if administered earlier in the course of the condition. Typically, cognitive impairments include reduced processing speed and deficits in executive functioning and attention. These symptoms are also typically accompanied by gait abnormalities and urinary incontinence. Brain imaging to reveal ventricular volume and characterize brain displacement is often necessary to confirm the diagnosis.