Neuro6 Hydrocephalus

Question 1

Normal pressure hydrocephalus

Answer 1

“Wet, wobbly, and wacky.” Results in increased subarachnoid space volume but no increase in CSF pressure. Expansion of ventricles distorts the fibers of the corona radiata and leads to the clinical triad of
dementia, ataxia, and urinary incontinence (a reversible cause of dementia in the elderly)

Question 2

Communicating hydrocephalus

Answer 2

Decreases CSF absorption by arachnoid villi, which can

lead to increased intracranial pressure, papilledema, and herniation (e.g., arachnoid scarring postmeningitis).

Question 3

Obstructive (noncommunicating) hydrocephalus

Answer 3

Caused by a structural blockage of CSF circulation within the ventricular system (e.g., stenosis of the aqueduct of Sylvius).

Question 4

Hydrocephalus ex vacuo

Answer 4

Appearance of increased CSF in atrophy (e.g., Alzheimer’s disease, advanced HIV, Pick’s disease) . Intracranial pressure is normal; triad is not seen.