Normal pressure hydrocephalus role of radionuclide cisternography

Area of Science:

• Neurology
• Nuclear Medicine
• Radiology

Background:

• Normal pressure hydrocephalus (NPH) presents with a characteristic triad of gait apraxia, dementia, and urinary incontinence.
• Accurate diagnosis of NPH is crucial for timely intervention, often involving shunt surgery.

Purpose of the Study:

• To evaluate the utility of radionuclide cisternography in diagnosing NPH.
• To assess the correlation between cisternographic findings and patient response to shunt surgery.

Main Methods:

• Seventeen patients with suspected NPH underwent isotope cisternography using 99m-Technetium labelled Diethylene triamine pentacetic acid (DTPA).
• Images were analyzed at 1, 2, 4, and 24 hours post-injection, focusing on ventricular reflux and tracer distribution.
• Patient response to CSF taps and shunt surgery was monitored over an 11-month follow-up period.

Main Results:

• Persistent ventricular reflux at 24 hours showed 87.5% sensitivity and 77.8% specificity for predicting a good shunt response.
• Absence or patchy radioactivity on the brain surface demonstrated 62.5% sensitivity and 88.89% specificity.
• Clinical factors like gait apraxia preceding dementia, incontinence, and periventricular lucency on CT predicted positive surgical outcomes.

Conclusions:

• Radionuclide cisternography is a valuable diagnostic tool for NPH when integrated with clinical and radiological assessments.
• Specific cisternographic patterns can help predict the likelihood of successful shunt surgery in NPH patients.