MedLink Neurology Podcast is delighted to feature selected episodes from BrainWaves, courtesy of James E Siegler MD, its originator and host. BrainWaves is an academic audio podcast whose mission is to educate medical providers through clinical cases and topical reviews in neurology, medicine, and the humanities, and episodes originally aired from 2016 to 2021.   Originally released: November 22, 2018   Of the "reversible" causes of dementia, normal pressure hydrocephalus may be the most controversial. But there is something to be said about how surgical intervention alters the physiology of patients who present with gait impairment, ventriculomegaly, and normal CSF pressure. This week on the show, we discuss the clinical features and the controversy behind this diagnosis.   Produced by James E Siegler. Music by Ghost, Jon Watts, Julie Maxwell, Komiku, and Kevin McLeod. Sound effects by Mike Koenig, Daniel Simion. BrainWaves' podcasts and online content are intended for medical education only and should not be used for clinical decision-making. Be sure to follow us on Twitter @brainwavesaudio for the latest updates to the podcast.   REFERENCES   Gallia GL, Rigamonti D, Williams MA. The diagnosis and treatment of idiopathic normal pressure hydrocephalus. Nat Clin Pract Neurol 2006;2(7):375-81. PMID 16932588 Kazui H, Miyajima M, Mori E, Ishikawa M; SINPHONI-2 Investigators. Lumboperitoneal shunt surgery for idiopathic normal pressure hydrocephalus (SINPHONI-2): an open-label randomised trial. Lancet Neurol 2015;14(6):585-94. PMID 25934242 Klassen BT, Ahlskog JE. Normal pressure hydrocephalus: how often does the diagnosis hold water? Neurology 2011;77(12):1119-25. PMID 21849644 Relkin N, Marmarou A, Klinge P, Bergsneider M, Black PM. Diagnosing idiopathic normal-pressure hydrocephalus. Neurosurgery 2005;57(3 Suppl):S4-16; discussion ii-v. PMID 16160425 Williams MA, Relkin NR. Diagnosis and management of idiopathic normal-pressure hydrocephalus. Neurol Clin Pract 2013;3(5):375-85. PMID 24175154   We believe that the principles expressed or implied in the podcast remain valid, but certain details may be superseded by evolving knowledge since the episode’s original release date.