Normal pressure hydrocephalus

Case contribution: Dr Radhiana Hassan


  • A 72 years old lady with background history of hyperlipidaemia and DM
  • Semidependant and ambulating mostly using wheelchair
  • Also had recurrent CVA
  • She become forgetful since lass 2 years,
  • Unable to control bowel motion
  • Clinically she is intermittently delirious with paucity of speech, appears thin and undernourished, contracture at left upper and lower limbs with hyperreflexia.
  • Lumbar puncture shows opening pressure of 12 cmH2O
  • CSF analysis Glucose 4.8, Protein 0.5, Albumin 264, no organism stain, AFB negative and cyctology acellular smear with CSF RPR negative
Plain CT brain in axial plane soft tissue window

CT scan findings:

  • There is generalised cerebral atrophy
  • Dilatation of the lateral, third and fourth ventricles
  • Dilatation of the temporal horn of lateral ventricles bilaterally
  • Bilateral and symmetrical hypodensity at periventricular region
  • Narrowing of the callosal angle
  • Evans index measured 0.4
  • Depression of the posterior fornix and shortening of mamillopontine distance
  • Narrowing of CSF space at vertex (tight sign)

Diagnosis: Normal pressure hydrocephalus


  • Normal pressure hydrocephalus is also called as malresorptive hydrocephalus
  • It is a form of communicating hydrocephalus with normal or slightly elevated cerebrospinal fluid pressure
  • Normal CSF pressure in adult is 7-16 mmH2O
  • Majority are idiopathic
  • The incidence is higher in elderly population
  • The classical findings are urinary incontinence, deterioration in cognition (dementia), gait disturbances
  • Features that favor hydrocephalus include
    • Dilatation of temporal horns
    • Lack of dilatation of parahippocampal fissure
    • Increased frontal horn radius
    • Acute ventricular angle
    • Periventricular odema from transependymal flow
    • Intraventricular flow void from CSF movement on MRI
    • Widening of the third ventricular recesses; midsagittal plane
    • Depression of posterior fornix; midsagittal plane
    • Decreased mamillopontine distance;midsagittal plane, normal 7-9 mm
    • Narrow callosal angle: normal 100-120 degrees, in NPH 50-80 degrees
    • Cingulate sulcus sign- MRI feature


Author: radhianahassan