Emory University has contributed to a significant international study published in the New England Journal of Medicine on September 16, which demonstrates that brain shunt surgery can substantially improve walking and balance in older adults diagnosed with idiopathic normal pressure hydrocephalus (iNPH). This condition, characterized by an accumulation of cerebrospinal fluid in the brain, often leads to memory problems, difficulty walking, and urinary incontinence among seniors.
The Placebo-Controlled Effectiveness in iNPH Shunting (PENS) Trial is noted as the first large-scale randomized study confirming the benefits of shunt surgery for iNPH. According to researchers, patients who received a functioning brain shunt experienced faster walking speeds, improved balance, and a lower likelihood of falling compared to those who did not receive active treatment. These results may influence future standards of care for this treatable disorder.
The multicenter trial was funded by the National Institutes of Health and involved 99 participants across 17 sites in the United States, Canada, and Sweden. Each participant underwent surgery to implant a programmable brain shunt designed to drain excess cerebrospinal fluid. Half had their devices activated immediately while the others received placebo settings that did not allow drainage; neither patients nor doctors were aware of group assignments.
After three months, data showed that individuals with active shunts had significantly improved outcomes. The open-shunt group’s average walking speed increased by 0.23 meters per second—more than twice what is considered meaningful improvement for older adults—while those in the placebo group saw almost no change. Additionally, 80% of patients with working shunts experienced meaningful improvements versus only 24% among those with inactive devices. Falls were also less common: just 25% of the active group reported falling compared to 46% in the placebo cohort.
“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, neurosurgeon at Emory Healthcare and Pamela R. Rollins Chairman and Professor of Neurosurgery at Emory University School of Medicine as well as co-author on 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 essential for both conducting this research and managing iNPH effectively in clinical practice.
Despite being treatable through surgical intervention, iNPH is frequently overlooked or mistaken for normal aging processes; estimates suggest only about 20% of eligible patients are referred for evaluation or treatment.
“There’s a real opportunity here to change how we identify and treat iNPH,” Barrow stated. “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.”
Research indicates that up to 1.5% of people in their late sixties—and as many as one out of every thirteen individuals over age eighty-six—may be affected by iNPH. Symptoms include gait disturbance, cognitive decline, and bladder control loss; these are sometimes misattributed to other age-related conditions rather than recognized as signs warranting further investigation such as brain imaging or temporary CSF drainage tests.
Currently, implanting a shunt remains the only effective treatment option available.
The PENS trial will continue monitoring participants over twelve months to assess longer-term impacts on cognition, daily living activities, and overall quality of life; preliminary data already indicate broader benefits beyond mobility improvements alone.
Researchers are also pursuing development efforts aimed at noninvasive diagnostic methods intended to facilitate earlier detection so more patients can access appropriate care sooner.
Johns Hopkins University School of Medicine led this project along with support from organizations such as the Adult Hydrocephalus Clinical Research Network; additional participating institutions included University of Washington, University of Calgary, Mayo Clinic, Oregon Health & Science University, University of Miami, University of South Florida, University of California-Davis, University of Utah among others.
For further details about the PENS trial visit clinicaltrials.gov.
