Idiopathic normal pressure hydrocephalus; treatment and outcome in the Region of Southern Denmark.

Objective: Idiopathic normal pressure hydrocephalus (iNPH) is a prevalent and cost-effective disease to treat. However, no gold standard exists to confidently select patients for shunt surgery. The aim of this study was to investigate how patients with suspected iNPH at our center responded to shunt surgery and to compare pre-surgical variables between shunt responders and non-responders.

Methods: Preoperative baseline characteristics, MRI and/or CT scans were retrospectively obtained in 55 shunt-operated iNPH patients. Evan's index, third ventricle diameter, dilation of Sylvian fissures, tight high convexity, focal sulci, callosal angle, Rout value, MMSE score, CSF phosphorylated tau, CSF tau, and a combination of radiologic findings (DESH score) were compared according to whether or not patients expressed satisfactory response to shunt treatment at 1-month follow-up.

Results: Multiple logistic regression controlling for age and gender (α = 0.05) showed that tight high convexity, dilated Sylvian fissures, focal sulci, CSF tau, CSF phosphorylated tau, and DESH score correlated significantly with subjective shunt response at 1-month follow-up.

Conclusion: In line with current literature, Shunt responders had lower levels of CSF tau and CSF phosphorylated tau compared to non-responders. While commonly used radiologic markers are of value, they can be aggregated into a score for better selection of shunt candidates.