see also:

• hydrocephalus
• weakness of the lower limb(s) / weak in the knees
• The patient with a V-P shunt (VPS)

• normal pressure hydrocephalus can occur at any age but most commonly occurs in the elderly when it may present as dementia with disturbed gait (usually wide-based) and urinary incontinence
• although it may follow an intracranial pathology such as subarachnoid haemorrhage (SAH), in many cases no obvious cause is found

• exceedingly rare under age 60yrs
• 0.2% to 1.5% of those aged 70-79yrs
• 3.7% to 5.9% of those aged 80 and older (criteria meeting probable diagnosis)

• increasingly impaired cognition over many months and dementia
• disturbed gait disturbance (usually wide-based)
  • the cardinal sign is a hypokinetic gait disorder in which the feet look as though they are glued to the floor
  • reduced gait velocity, due to a diminished and highly variable stride length as with Parkinson's disease
  • specific features are a broad based gait pattern with outward rotated feet and a diminished height of the steps ¹⁾
• urinary incontinence

• CT scan usually demonstrates the hydrocephalus
• LP with manometry is required to demonstrate normal CSF pressures

• if incidental finding on CT brain and no symptoms from it, then refer to neurology OP for LP manometry
• if symptomatic then d/w neurology
  • if proven, may need V-P shunt