What does normal pressure hydrocephalus look like on imaging?

• A. Enlarged sulci
• B. Widely dilated ventricles
• C. Small ventricular size
• D. Soft brain tissue

Answer: (B)

Normal pressure hydrocephalus (NPH) is characterized on imaging by widely dilated ventricles, despite normal ventricular pressure. This condition typically presents with a triad of symptoms: gait disturbance, cognitive dysfunction, and urinary incontinence. The key imaging finding in NPH is the disproportionate enlargement of the ventricles, specifically the lateral and third ventricles, which occurs without a corresponding increase in intracranial pressure.

The ventricles enlarge in NPH due to the accumulation of cerebrospinal fluid (CSF) that occurs as a result of impaired absorption or other mechanisms, leading to the classic imaging finding of ventricular dilation. This dilatation can also lead to a compensatory appearance of the sulci, where the cerebral cortex may appear to be thinner, but the ventricles remain the primary focus in the diagnosis.

Thus, the recognition of widely dilated ventricles on imaging studies is crucial for diagnosing normal pressure hydrocephalus, making it the correct answer in this question.