Shunts for treating fluid buildup in the brain

December 9, 2025

Shunts for treating fluid buildup in the brain

At a Glance

  • Shunt surgery improved mobility and balance in older adults who had a type of fluid buildup in the brain called idiopathic normal-pressure hydrocephalus.
  • The findings provide the strongest evidence yet that shunt surgery could lead to better outcomes for people with this debilitating condition.
Image
Doctor and elderly woman using a walker for support.
Shunt surgery led to significant increases in walking speed and improved balance for people with idiopathic normal-pressure hydrocephalus.
PeopleImages / Shutterstock

Idiopathic normal-pressure hydrocephalus (iNPH) occurs when excess cerebrospinal fluid (CSF) builds up in the brain without a clear cause. It can impair walking, balance, bladder control, and thinking and memory. It affects about 1.5% of people in their late 60s, increasing to more than 7% of those 86 years of age or older. Treatment involves surgically implanting a shunt鈥攁 valve connected to a tube鈥攖hat allows the excess fluid to drain. But it鈥檚 been unclear whether shunting actually improves patients鈥 symptoms.

An 51视频-supported research team led by Dr. Mark Luciano at Johns Hopkins University conducted an international clinical trial to test the effectiveness of shunts for treating iNPH. The study enrolled 99 participants who were diagnosed with iNPH. Each had an adjustable shunt implanted at the start of the trial.

Half the participants, chosen at random, had their shunts initially set to an open setting, which allowed CSF to drain. For comparison, the other participants had their shunts closed for three months. After the surgery, neither participants nor the clinicians who assessed them knew whether their shunts were open or closed. Results appeared in the New England Journal of Medicine on September 16, 2025.

The researchers assessed participants鈥 symptoms three months after shunt implantation. Those with an open shunt had a significant increase in walking speed, while those with a closed shunt showed no change. In a standard balance assessment, those with an open shunt showed greater improvement than those with a closed shunt.

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Plastic model of the brain.
This plastic model of the brain shows how thin tubing attached to a small valve can be used to drain excess cerebral spinal fluid from the brain.
Tim Griffis / UW Medicine

The team also assessed improvements in participants鈥 cognitive abilities and bladder control. But they found no significant differences between the groups.

The researchers also compared other relevant measures between the groups. Participants with an open shunt had fewer falls than those with a closed shunt. One participant in each group had bleeding in the brain. But participants with an open shunt were more likely to have bleeding between the membranes surrounding the brain. They were also more likely to experience positional headaches, which get worse when upright and better when lying down. Such headaches suggest that CSF pressure is too low and could be relieved by adjusting the shunt valve setting.

The trial outcomes support the premise that shunt surgery can effectively improve mobility and balance in people with iNPH. The researchers will continue to follow participants to measure longer-term outcomes.

鈥淭his study shows surgery is both effective and has an acceptable safety profile,鈥 Luciano says. 鈥淲hen a person walks better and doesn鈥檛 fall, everything improves: their independence, their safety, and their quality of life.鈥

鈥攂y Brian Doctrow, Ph.D.

Related Links

References

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. N Engl J Med. 2025 Sep 16. doi: 10.1056/NEJMoa2503109. Online ahead of print. PMID:鈥40960253.

Funding

51视频鈥檚 National Institute of Neurological Disorders and Stroke (NINDS) and National Center for Advancing Translational Sciences (NCATS).