Research and evidence

Research becomes useful when its question resembles the reader's clinical situation. A trial in selected older adults with iNPH does not answer the same question as a trial in infants after infection. Read the population, comparator, endpoint and observation period together.

Selected iNPH patients: the PENS trial

PENS randomized 99 people whose walking had responded to temporary CSF drainage. All received a shunt; the comparison was an open valve versus a placebo valve setting, rather than surgery versus no operation. The primary endpoint was gait-speed change at three months. The reported analysis included 49 participants per arm with imputation for missing data. The adjusted between-group difference was 0.21 m/s (95% CI 0.12–0.31). A gait/balance measure improved, while cognitive and bladder secondary measures did not show significant benefit at that time.1

Enrollment stopped after a planned interim analysis. Bleeding and positional headache were more frequent with open shunting; falls were more frequent in the placebo arm. Selection excluded secondary hydrocephalus, people unable to walk the testing distance, and chronic anticoagulation. These results cannot establish general dementia reversal, personal benefit or long-term safety.1

Infants after infection: one cohort, two reports

The Ugandan trial randomized 100 infants younger than six months with postinfectious hydrocephalus: 51 to ETV-CPC and 49 to VP shunting. Its primary question was cognition at 12 months, assessed in 47 children in each group. No significant difference was detected. Procedure failure and brain/fluid volume were separate outcomes. Failure included treatment-related death or repeat surgery; crossovers were analyzed in their assigned groups.2

The five-year report followed the same original cohort. It retained 63 surviving children, 35/28 by original assignment; 34 had died and three were lost. Developmental and quality-of-life analyses used 60 children, 33/27 by assignment (Table 3); the reported imaging analyses also used 60 (Table 4). No significant group difference in the reported developmental or quality-of-life measures was detected. Attrition, underlying infection and the local resource setting matter. This is follow-up, not a second independent trial, and neither report proves universal equivalence or predicts a child's future.3

Shunt infection: BASICS

BASICS randomized 1,605 children and adults receiving a first VP shunt in UK/Ireland centers. Among 1,594 evaluable insertions, infection-related revisions occurred in 32/533 standard, 12/535 antibiotic-impregnated and 31/526 silver-catheter recipients, with median follow-up of 22 months. The endpoint was time to infection-related failure. This supports an infection-prevention finding; it does not promise freedom from mechanical failure or identify the best device for an individual.4

Guidance

The CNS pediatric guideline treats shunts and ETV as options within clinical selection, with evidence strength varying by question. Its premature-infant chapter addresses a particular cause group. The 2021 Japanese iNPH guideline addresses imaging and testing with explicit limitations. A negative tap test or absent DESH pattern cannot independently exclude benefit. These are professional interpretation questions.567

Hamilton and colleagues' 2025 publication is a review about guidelines. It isn't a new society guideline.8

References

1. Luciano MG et al. A Randomized Trial of Shunting for Idiopathic Normal-Pressure Hydrocephalus. N Engl J Med. 2025;393:2198–2209. doi:10.1056/NEJMoa2503109. Source ↩
2. Kulkarni AV et al. Endoscopic Treatment versus Shunting for Infant Hydrocephalus in Uganda. N Engl J Med. 2017;377:2456–2464. doi:10.1056/NEJMoa1707568. Source ↩
3. Mbabazi-Kabachelor E et al. Five-year outcomes after surgical treatment of infant postinfectious hydrocephalus in sub-Saharan Africa. J Neurosurg Pediatr. 2025. doi:10.3171/2025.1.PEDS24417. Source ↩
4. Mallucci CL et al. Antibiotic or silver versus standard ventriculoperitoneal shunts (BASICS). Lancet. 2019;394:1530–1539. doi:10.1016/S0140-6736(19)31603-4. Source ↩
5. CNS. Pediatric Hydrocephalus Guideline, Part 4. 2014; updated 2020. Source ↩
6. CNS. Pediatric Hydrocephalus Guideline, Part 2. 2014; updated 2020. Source ↩
7. Nakajima M et al. Guidelines for Management of Idiopathic Normal Pressure Hydrocephalus (Third Edition). Neurol Med Chir. 2021;61:63–97. doi:10.2176/nmc.st.2020-0292. Source ↩
8. Hamilton MG, Williams MA, Edwards S, Tullberg M. Guidelines for Diagnosis and Management of Idiopathic Normal Pressure Hydrocephalus. Neurosurg Clin N Am. 2025;36:199–205. doi:10.1016/j.nec.2024.12.006. PubMed ↩