Normal pressure hydrocephalus
Normal pressure hydrocephalus occurs when excess fluid accumulates in the brain, but without causing pressure to build up in the brain tissue.
Rarer causes of dementia
Symptoms include difficulties with walking, dementia and urinary incontinence. In most cases the cause is unknown, but it sometimes develops after recovery from a head injury, brain haemorrhage (a bleed in the brain) or severe meningitis (an infection of the tissue surrounding the brain).
Treatment involves surgery to drain excess fluid. The success of this treatment varies depending on how early the condition is diagnosed, but symptoms may improve after surgery and some people make an almost complete recovery.