by Isabella Colonna
For November we have selected Luciano MG, Williams MA, Hamilton MG, Katzen HL, Dasher NA, Moghekar A, Hua J, Malm J, Eklund A, Alpert Abel N, Raslan AM, Elder BD, Savage JJ, Barrow DL, Shahlaie K, Jensen H, Zwimpfer TJ, Wollett J, Hanley DF, Holubkov R; PENS Trial Investigators and the Adult Hydrocephalus Clinical Research Network. A Randomized Trial of Shunting for Idiopathic Normal-Pressure Hydrocephalus. N Engl J Med. 2025 Sep 16. doi: 10.1056/NEJMoa2503109. Epub ahead of print. PMID: 40960253.
Idiopathic normal-pressure hydrocephalus (iNPH) is a neurological disorder characterised by impairment in gait, cognition and bladder control in older adults. Although cerebrospinal fluid (CSF) shunting has long been used as a treatment, its clinical effectiveness remains uncertain.
This study reports the results of a multicentre, double-blind, randomised, placebo-controlled trial involving patients with iNPH who were selected for ventriculoperitoneal shunt surgery on the basis of gait-velocity improvement following temporary CSF drainage, in accordance with the current international guidelines.
A total of 99 participants were randomly assigned in a 1:1 ratio to receive either an open-shunt valve (opening pressure, 110 mm H₂O) or a placebo valve (opening pressure, >400 mm H₂O). At the three-month follow-up, a significant increase in gait velocity was observed in the open-shunt group compared with the placebo group. Similarly, participants in the open-shunt group demonstrated a statistically significant improvement in the Tinetti scale. However, there were no significant between-group differences in the Montreal Cognitive Assessment (MoCA) score or in the Overactive Bladder Questionnaire–Short Form score.
Regarding adverse events, falls occurred more frequently in the placebo group (46% vs. 24%), whereas subdural bleeding (12% vs. 2%) and positional headaches (59% vs. 28%) were more common in the open-shunt group. The incidence of cerebral bleeding did not differ between groups (2% in both).
In conclusion, this trial demonstrates that shunt surgery in patients with idiopathic normal-pressure hydrocephalus was associated, at three months, with significant improvement in gait performance. These findings support the benefit of shunt surgery in appropriately selected patients with iNPH.
