What triad characterizes normal pressure hydrocephalus and what imaging finding supports the diagnosis?

What triad characterizes normal pressure hydrocephalus and what imaging finding supports the diagnosis?

• A. Gait disturbance, urinary incontinence, and cognitive impairment; ventriculomegaly with enlarged ventricles out of proportion to sulci
• B. Gait disturbance, falls, and memory loss; normal ventricles
• C. Headache, fever, neck stiffness; enlarged sulci
• D. Seizures, language impairment; ventricles normal

Answer: (A)

Normal pressure hydrocephalus shows a distinct triad: gait disturbance (often an magnetic, wide-based gait), urinary incontinence, and cognitive impairment. The imaging clue is ventriculomegaly with the ventricles enlarged out of proportion to the cortical sulci (ventricles look big for how folded the brain surface is), sometimes described by an Evans index over a normal threshold. This pattern happens because CSF accumulates and expands the ventricles without a sustained high opening pressure, and it helps differentiate hydrocephalus from brain atrophy, where sulci are enlarged but the ventricles aren’t disproportionately big. The gait and cognitive issues come from disruption of periventricular white matter and frontal-subcortical pathways, while urinary incontinence ties to frontal lobe involvement. Other options don’t fit: they either miss the full triad, show a different clinical syndrome (like meningitis), or have normal ventricles inconsistent with hydrocephalus.

Normal pressure hydrocephalus shows a distinct triad: gait disturbance (often an magnetic, wide-based gait), urinary incontinence, and cognitive impairment. The imaging clue is ventriculomegaly with the ventricles enlarged out of proportion to the cortical sulci (ventricles look big for how folded the brain surface is), sometimes described by an Evans index over a normal threshold. This pattern happens because CSF accumulates and expands the ventricles without a sustained high opening pressure, and it helps differentiate hydrocephalus from brain atrophy, where sulci are enlarged but the ventricles aren’t disproportionately big. The gait and cognitive issues come from disruption of periventricular white matter and frontal-subcortical pathways, while urinary incontinence ties to frontal lobe involvement. Other options don’t fit: they either miss the full triad, show a different clinical syndrome (like meningitis), or have normal ventricles inconsistent with hydrocephalus.