Editing Normal pressure hydrocephalus (section)

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| synonyms        = Malresorptive hydrocephalus
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'''Normal pressure hydrocephalus''' ('''NPH'''), also called '''malresorptive hydrocephalus''', is a form of communicating [[hydrocephalus]] in which excess [[cerebrospinal fluid]] (CSF) builds up in the [[Ventricles (brain)|ventricles]], leading to normal or slightly elevated [[cerebrospinal fluid pressure]]. The fluid build-up causes the [[ventriculomegaly|ventricles to enlarge]] and the pressure inside the head to increase, compressing surrounding brain tissue and leading to neurological complications. Although the cause of '''idiopathic''' (also referred to as '''primary''') '''NPH''' remains unclear, it has been associated with various co-morbidities including hypertension, diabetes mellitus, Alzheimer's disease, and hyperlipidemia.<ref>{{Cite journal |last1=Pyykkö |first1=Okko T. |last2=Nerg |first2=Ossi |last3=Niskasaari |first3=Hanna-Mari |last4=Niskasaari |first4=Timo |last5=Koivisto |first5=Anne M. |last6=Hiltunen |first6=Mikko |last7=Pihlajamäki |first7=Jussi |last8=Rauramaa |first8=Tuomas |last9=Kojoukhova |first9=Maria |last10=Alafuzoff |first10=Irina |last11=Soininen |first11=Hilkka |last12=Jääskeläinen |first12=Juha E. |last13=Leinonen |first13=Ville |date=April 2018 |title=Incidence, Comorbidities, and Mortality in Idiopathic Normal Pressure Hydrocephalus |url=https://pubmed.ncbi.nlm.nih.gov/29374607 |journal=World Neurosurgery |volume=112 |pages=e624–e631 |doi=10.1016/j.wneu.2018.01.107 |issn=1878-8769 |pmid=29374607}}</ref><ref>{{Cite journal |last1=Kuriyama |first1=Nagato |last2=Miyajima |first2=Masakazu |last3=Nakajima |first3=Madoka |last4=Kurosawa |first4=Michiko |last5=Fukushima |first5=Wakaba |last6=Watanabe |first6=Yoshiyuki |last7=Ozaki |first7=Etsuko |last8=Hirota |first8=Yoshio |last9=Tamakoshi |first9=Akiko |last10=Mori |first10=Etsuro |last11=Kato |first11=Takeo |last12=Tokuda |first12=Takahiko |last13=Urae |first13=Akinori |last14=Arai |first14=Hajime |date=March 2017 |title=Nationwide hospital-based survey of idiopathic normal pressure hydrocephalus in Japan: Epidemiological and clinical characteristics |journal=Brain and Behavior |volume=7 |issue=3 |pages=e00635 |doi=10.1002/brb3.635 |issn=2162-3279 |pmc=5346522 |pmid=28293475}}</ref><ref>{{Cite journal |last1=Liew |first1=Boon Seng |last2=Takagi |first2=Kiyoshi |last3=Kato |first3=Yoko |last4=Duvuru |first4=Shyam |last5=Thanapal |first5=Sengottuvel |last6=Mangaleswaran |first6=Balamurugan |date=2019 |title=Current Updates on Idiopathic Normal Pressure Hydrocephalus |journal=Asian Journal of Neurosurgery |volume=14 |issue=3 |pages=648–656 |doi=10.4103/ajns.AJNS_14_19 |doi-access=free |issn=1793-5482 |pmc=6703007 |pmid=31497081}}</ref> Causes of '''secondary NPH''' include trauma, hemorrhage, or infection.<ref name=":0">{{Cite journal |last1=Williams |first1=Michael A. |last2=Malm |first2=Jan |date=April 2016 |title=Diagnosis and Treatment of Idiopathic Normal Pressure Hydrocephalus |journal=Continuum (Minneapolis, Minn.) |volume=22 |issue=2 Dementia |pages=579–599 |doi=10.1212/CON.0000000000000305 |issn=1538-6899 |pmc=5390935 |pmid=27042909}}</ref> The disease presents in a classic triad of symptoms, which are [[memory impairment]], [[urinary frequency]], and [[balance problems]]/[[gait deviations]] (note: use of this triad as the diagnostic method is obsolete; the triad symptoms appear at a relatively late stage, and each of the three can be caused by a number of other conditions<ref name=nakajima-2021>{{cite journal|title=Guidelines for Management of Idiopathic Normal Pressure Hydrocephalus (Third Edition): Endorsed by the Japanese Society of Normal Pressure Hydrocephalus|doi=10.2176/nmc.st.2020-0292|pmid=33455998|journal=Neurologia Medico-Chirurgica |date= Feb 2021 |volume=61|issue=2|pages=63–97|last1=Nakajima |first1=Madoka |last2=Yamada |first2=Shigeki |last3=Miyajima |first3=Masakazu |last4=Ishii |first4=Kazunari |last5=Kuriyama |first5=Nagato |last6=Kazui |first6=Hiroaki |last7=Kanemoto |first7=Hideki |last8=Suehiro |first8=Takashi |last9=Yoshiyama |first9=Kenji |last10=Kameda |first10=Masahiro |last11=Kajimoto |first11=Yoshinaga |last12=Mase |first12=Mitsuhito |last13=Murai |first13=Hisayuki |last14=Kita |first14=Daisuke |last15=Kimura |first15=Teruo |last16=Samejima |first16=Naoyuki |last17=Tokuda |first17=Takahiko |last18=Kaijima |first18=Mitsunobu |last19=Akiba |first19=Chihiro |last20=Kawamura |first20=Kaito |last21=Atsuchi |first21=Masamichi |last22=Hirata |first22=Yoshihumi |last23=Matsumae |first23=Mitsunori |last24=Sasaki |first24=Makoto |last25=Yamashita |first25=Fumio |last26=Aoki |first26=Shigeki |last27=Irie |first27=Ryusuke |last28=Miyake |first28=Hiroji |last29=Kato |first29=Takeo |last30=Mori |first30=Etsuro |pmc=7905302 |display-authors=1 }}</ref><ref name=fasano-2021-UofT>{{cite web|url=https://www.youtube.com/watch?v=HUuytoSBLlM|title=Normal Pressure Hydrocephalus: a neurologist's perspective|website=[[YouTube]] |date=2022-11-01|access-date=2022-08-10}}</ref>). The disease was first described by [[Salomón Hakim]] and Raymond Adams in 1965.<ref name="pmid14303656">{{cite journal | vauthors = Adams RD, Fisher CM, Hakim S, Ojemann RG, Sweet WH | title = Symptomatic Occult Hydrocephalus with Normal Cerebrospinal-Fluid Pressure | journal = The New England Journal of Medicine | volume = 273 | issue = 3 | pages = 117–26 | date = July 1965 | pmid = 14303656 | doi = 10.1056/NEJM196507152730301 }}</ref>

The usual treatment is surgical placement of a [[ventriculoperitoneal shunt]] to drain excess CSF into the lining of the [[abdomen]] where the CSF will eventually be absorbed. An alternate, less invasive treatment would be [[Endoscopic third ventriculostomy]]. NPH is often misdiagnosed as other conditions including [[Meniere's disease]] (due to balance problems), [[Parkinson's disease]] (due to gait) or [[Alzheimer's disease]] (due to cognitive dysfunction).