A 77 year old male presents with history of enuresis and change in behavior. Examination: waddling gait. What is the most likely diagnosis?

The key is C. Normal pressure hydrocephalus. [Normal pressure hydrocephalus (NPH) is an

abnormal buildup of cerebrospinal fluid (CSF) in the brain's ventricles, or cavities. It occurs if the normal

flow of CSF throughout the brain and spinal cord is blocked in some way. This causes the ventricles to

enlarge, putting pressure on the brain. Age (usually occurs in 60s or 70s), loss of bladder control

(enuresis), waddling gait and behavior change and dementia are all features of normal pressure

hydrocephalus].