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However, up to 40% of patients who undergo ventriculoperitoneal (VP) shunting fail to exhibit sustained improvement. The management of iNPH remains challenging, particularly for non-responders who deteriorate despite surgery. We aimed to determine what features differentiate between long term versus short term responders and do valve adjustments affect their outcome?<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Material and methods<\/jats:title>\n                    <jats:p>We included patients that underwent ventriculoperitoneal shunt surgery for iNPH between December 2006 and December 2016. Patients were stratified as early (&lt;\u20096 months) and late (&gt;\u20096 months) non-responders, and responders. Descriptive statistics, time series plotting, chi-squared tests, and ANOVA analyses were used.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>Our cohort of 65 iNPH patients exhibited a mean follow-up of 3.75 years and consisted of 53.8% early non-responders, 15.4% late non-responders, and 30.8% responders. Comorbidities were distributed across all groups but did not significantly differentiate between response categories. A considerable subset experienced symptom deterioration after the six months mark. Shunt valve adjustments were more frequent in non-responders but did not prevent continued deterioration. In late non-responders, valve adjustments merely slowed symptom progression, without halting deterioration.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>Our study underscores that valve pressure adjustments in early non-responders, who likely never benefit from shunt surgery, are not effective, and highlights the emergence of a late non-responder phenotype, where symptom deterioration becomes evident 6 months post-shunting. Our findings outline the need to explore alternative treatment strategies for managing symptoms in iNPH non-responders, as well as prolonged follow-up regimens to monitor late non-responders.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1007\/s00701-025-06663-9","type":"journal-article","created":{"date-parts":[[2025,9,13]],"date-time":"2025-09-13T06:39:19Z","timestamp":1757745559000},"update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":4,"title":["Predictors of shunt response in iNPH: differentiating responders, early and late non-responders, and the role of valve adjustments"],"prefix":"10.1007","volume":"167","author":[{"given":"Santhosh G.","family":"Thavarajasingam","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mahmoud","family":"El-Khatib","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Stefania Roxana","family":"Kalb","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ahmed","family":"Salih","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Daniele S. 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Consent is not required for this study as it is a retrospective cohort study with routine patient data and management, this research has no effect on patient treatment.","order":2,"name":"Ethics","group":{"name":"EthicsHeading","label":"Ethics approval"}},{"value":"Consent is not required for this study as it is a retrospective cohort study with routine patient data and management, this research has no effect on patient treatment.","order":3,"name":"Ethics","group":{"name":"EthicsHeading","label":"Consent to participate"}},{"value":"Consent is not required for this study as it is a retrospective cohort study with routine patient data and management, this research has no effect on patient treatment.","order":4,"name":"Ethics","group":{"name":"EthicsHeading","label":"Consent for publication"}},{"value":"The authors declare no competing interests.","order":5,"name":"Ethics","group":{"name":"EthicsHeading","label":"Competing interests"}}],"article-number":"245"}}