Which condition is characterized by dementia, urinary incontinence, gait apraxia, with language spared?

• A. Normal pressure hydrocephalus (NPH)
• B. Lewy body dementia (LBD)
• C. Progressive supranuclear palsy (PSP)
• D. Alzheimer's disease

Answer: (C)

The key idea is recognizing a pattern of cognitive change tied to specific motor planning problems. Gait apraxia indicates a deficit in orchestrating the steps and coordinating movement, which points to frontal–subcortical circuit involvement rather than a primary memory problem. In progressive supranuclear palsy, degeneration in brain regions that control movement and executive planning produces early gait difficulty with impaired gait initiation and planning (gait apraxia), along with a subcortical type of cognitive change where language is relatively preserved early on. Urinary symptoms can occur as the disease progresses due to autonomic and frontal involvement, fitting the described triad in a PSP context.

Normal pressure hydrocephalus also presents with dementia, gait disturbance, and urinary incontinence, but the gait is classically magnetic or shuffling rather than a true gait apraxia, and the overall profile emphasizes the hydrocephalic mechanism more than frontal–subcortical planning deficits. Lewy body dementia tends to show fluctuations, visual hallucinations, and a different pattern of parkinsonism, while Alzheimer’s disease centers on memory impairment with language and other cognitive domains affected in a different sequence and later on, rather than a primary gait-apraxia syndrome with language largely spared early.