Normal pressure hydrocephalus



Background

  • ↑CSF with gait, urinary and mentation symptoms.
  • Periventricular CSF (not global) so sacral (bladder and leg) motor fibres affected.

CT in NPH
CT in NPH - classically ↑ ventricular vol.
with normal SAH volume [normal(ish) sulci]

Clinical

Triad

  • Abnormal gait
  • Urinary incontinence
  • Dementia (reversible!)

History

  • Predominantly (not exclusively) elderly.
  • Altered gait is often the first symptom.
    • Classically "magnetic" gait (feet stuck to the floor).
    • ±pyramidal tract signs (e.g. ↑tone/spasticity), particularly of legs.
  • Urinary symptoms = detrusor over-activity (periventricular pathology).
  • Dementia - characteristic loss short term recall.

Signs

  • Altered cognition
  • Pyramidal - Gait, hypertonia (legs) ±↑plantars
    • leading to festinant gait of Parkinson's
  • Normal ICP (but ↑vol) = No papilloedema & normal opening pressure (LP).
  • No sensory signs

Differential Dx

  • Parkinson’s (rest tremor is unusual in NPH).
  • Alzheimers and other dementias.

Investigations

  • CT brain (very sensitive so a normal CT rules NPH out).
  • MRI is more specific (positive rules NPH in).
  • Diagnostic LP with CSF volume (>50ml) drainage (NPH will respond).
  • Vascular/inflam. dementia work-up (in-patient teams).
  • Levodopa trial if ?Parkinson’s (NPH will not respond).

Management

  • Admit Care of the Elderly for dementia / CSF shunt work-up.


Content By Dr Íomhar O' Sullivan 12/03/2019. Last review Dr ÍOS 13/03/19.