reported to be less than 1% in persons under the age of 65, and up to 3% for persons aged 65 or older. No difference in incidence is seen between men and women. Among individuals with dementia, the incidence of NPH is thought to be between 2 and 6%. See also Low pressure hydrocephalus References External links The Normal Pressure Hydrocephalus Center at Johns Hopkins Bayview Medical Center Normal Pressure Hydrocephalus at Cleveland Clinic When it really is NPH at Likvor Hydrocephalus in Adults at Spina Bifida Resource Center Brain disorders Geriatrics Ventricular system Medical triads