Emory University contributed to an international study published in the New England Journal of Medicine on September 16, which found that brain shunt surgery can significantly improve walking and balance in older adults diagnosed with idiopathic normal pressure hydrocephalus (iNPH). This condition, often overlooked and treatable, involves a buildup of cerebrospinal fluid in the brain and leads to symptoms such as memory problems, difficulty walking, and urinary incontinence among seniors.
The Placebo-Controlled Effectiveness in iNPH Shunting (PENS) Trial is the first large-scale randomized study to demonstrate the benefits of shunting surgery for iNPH. The trial showed that patients who received an active brain shunt experienced faster walking speeds, better balance, and fewer falls compared to those who received a placebo setting.
The study enrolled 99 patients across 17 sites in the United States, Canada, and Sweden. All participants underwent surgery to implant a programmable brain shunt. Half had their device activated immediately while the other half had it set to a placebo mode that did not drain fluid. Neither the patients nor their doctors knew which group they were assigned.
After three months, results indicated significant improvements for those with an active shunt. Walking speed increased by 0.23 meters per second on average—more than double what is considered meaningful for older adults—while walking speed remained unchanged for those in the placebo group. In addition, 80% of patients with an active shunt saw meaningful improvement versus just 24% in the placebo group. Falls were also less common: only 25% of the active group reported falling compared to 46% of those receiving placebo treatment.
“This study settles a decades-long debate and gives us the highest level of evidence that shunting works for iNPH,” said Daniel L. Barrow, MD, Pamela R. Rollins Chairman and Professor of Neurosurgery at Emory University School of Medicine and co-author of the study. “It’s especially meaningful for older adults, who often lose independence because of mobility issues and falls. These results show that early diagnosis and treatment can dramatically improve quality of life.”
Barrow emphasized that collaboration between neurosurgeons and neurologists was key to both conducting this research and managing iNPH effectively in clinical settings.
Despite its treatability, iNPH is frequently missed or mistaken for normal aging; experts estimate only about 20% of eligible patients are referred for evaluation. Barrow added: “There’s a real opportunity here to change how we identify and treat iNPH. Too often, these patients are told nothing can be done. This study shows that with the right diagnosis and intervention, we can give them a much better outcome.”
Researchers estimate up to 1.5% of people in their late sixties may have iNPH; prevalence increases with age to about one in thirteen over age eighty-six. Diagnosis usually requires brain imaging alongside tests assessing response to temporary fluid drainage; currently, implantation of a permanent shunt remains the only effective treatment.
The PENS trial will continue monitoring participants over twelve months for long-term effects on cognition, daily function, and quality of life; preliminary data suggest additional benefits beyond improved mobility. Efforts are underway to develop noninvasive diagnostic tools aimed at earlier detection so more patients receive timely care.
The PENS trial was led by Johns Hopkins University School of Medicine along with participation from institutions including Emory University School of Medicine as well as others such as University of Washington, Mayo Clinic, Oregon Health & Science University, University of Miami, University South Florida, UC Davis Medical Center and University of Utah.
For further details about this research visit clinicaltrials.gov.
