Hydrocephalus

==Treatments==
===Procedures===
[[File:Khidmat Masy Hydrocephalus (19042957419).jpg|thumb|upright=1.2|Baby recovering from shunt surgery]]
Hydrocephalus treatment is surgical, creating a way for the excess fluid to drain away. In the short term, an [[external ventricular drain]] (EVD), also known as an extraventricular drain or ventriculostomy, provides relief. In the long term, some people will need any of various types of [[cerebral shunt]]. It involves the placement of a ventricular [[catheter]] (a tube made of [[silastic]]) into the cerebral ventricles to bypass the flow obstruction/malfunctioning arachnoidal granulations and drain the excess fluid into other body cavities, from where it can be resorbed. Most shunts drain the fluid into the [[peritoneum|peritoneal cavity]] ([[cerebral shunt|ventriculoperitoneal shunt]]), but alternative sites include the [[right atrium]] ([[cerebral shunt|ventriculoatrial shunt]]), [[pleura|pleural cavity]] ([[cerebral shunt|ventriculopleural shunt]]), and [[gall bladder|gallbladder]].
{{Further|topic=the non-invasive diagnostic medical device|ShuntCheck}}
A shunt system can also be placed in the lumbar space of the spine and have the CSF redirected to the peritoneal cavity ([[lumbar-peritoneal shunt]]).<ref name="pmid20508332">{{cite journal | vauthors = Yadav YR, Parihar V, Sinha M | title = Lumbar peritoneal shunt | journal = Neurology India | volume = 58 | issue = 2 | pages = 179–184 | year = 2010 | pmid = 20508332 | doi = 10.4103/0028-3886.63778 | doi-access = free }}</ref> An alternative treatment for obstructive hydrocephalus in selected people is the [[endoscopic third ventriculostomy]] (ETV), whereby a surgically created opening in the floor of the third ventricle allows the CSF to flow directly to the [[basal cisterns]], thereby shortcutting any obstruction, as in aqueductal stenosis. This may or may not be appropriate based on individual anatomy. For infants, ETV is sometimes combined with choroid plexus cauterization, which reduces the amount of cerebrospinal fluid produced by the brain. The technique, known as ETV/CPC, was pioneered in [[Uganda]] by neurosurgeon [[Benjamin Warf]] and is now in use in several U.S. hospitals.<ref>{{cite web |title=An American surgeon pioneers surgery for kids in Uganda that helps kids in the US |url=http://www.pri.org/stories/2015-04-27/american-surgeon-pioneers-surgery-kids-uganda-helps-kids-us |website=Public Radio International |access-date=2016-02-10 |url-status=live |archive-url=https://web.archive.org/web/20160302012700/http://www.pri.org/stories/2015-04-27/american-surgeon-pioneers-surgery-kids-uganda-helps-kids-us |archive-date=2016-03-02}}</ref><ref>{{cite journal | vauthors = Burton A | title = Infant hydrocephalus in Africa: spreading some good news | journal = The Lancet. Neurology | volume = 14 | issue = 8 | pages = 789–790 | date = August 2015 | pmid = 26091960 | doi = 10.1016/S1474-4422(15)00138-6 | s2cid = 35920581 }}</ref> Hydrocephalus can be successfully treated by placing a drainage tube (shunt) between the brain ventricles and abdominal cavity. Some risk exists of [[infection]] being introduced into the brain through these shunts, as they must be replaced as the person grows.<ref>{{cite journal | vauthors = Pople IK | title = Hydrocephalus and shunts: what the neurologist should know | journal = Journal of Neurology, Neurosurgery, and Psychiatry | volume = 73 | issue = suppl 1 | pages = i17–i22 | date = September 2002 | pmid = 12185257 | doi = 10.1136/jnnp.73.suppl_1.i17 | doi-broken-date = 31 January 2024 | pmc = 1765598 }}</ref><ref>{{Cite journal | vauthors = Engelhard III HH, Sahrakar K, Pang D | veditors = Talavera F |date=2022-03-03 |title=Neurosurgery for Hydrocephalus Treatment & Management: Approach Considerations, Medical Therapy, Surgical Therapy |url=https://emedicine.medscape.com/article/247387-treatment | journal = Medscape }}</ref>

===External hydrocephalus===
External hydrocephalus is a condition generally seen in infants which involves enlarged fluid spaces or subarachnoid spaces around the outside of the brain. This condition is generally [[benign]], and resolves spontaneously by two years of age<ref>{{cite book |url=https://books.google.com/books?id=0TC9Cns4Qz8C&q=Greenberg+handbook+of+neurosurgery+external+hydrocephalus&pg=PA307 |title=Handbook of Neurosurgery |isbn=9781604063264 | vauthors = Greenberg MS |date=2010-02-15 |publisher=Thieme |url-status=live |archive-url=https://web.archive.org/web/20230708022539/https://books.google.com/books?id=0TC9Cns4Qz8C&pg=PA307 |archive-date=2023-07-08}}</ref> and therefore usually does not require insertion of a shunt. Imaging studies and a good medical history can help to differentiate external hydrocephalus from [[subdural hematoma|subdural hemorrhages]] or symptomatic chronic extra-axial fluid collections which are accompanied by vomiting, headaches, and seizures.<ref>{{Cite web |title=Subdural Hematomas in the Elderly: The Great Neurological Imitator {{!}} 2000-03-01 {{!}} AHC Media: Continuing Medical Education Publishing {{!}} Relias Media - Continuing Medical Education Publishing |url=https://www.reliasmedia.com/articles/44955-subdural-hematomas-in-the-elderly-the-great-neurological-imitator |access-date=2022-05-17 |website=www.reliasmedia.com}}</ref><ref>{{Cite journal |title= External hydrocephalus: A probable cause for subdural hematoma in infancy|url=https://www.researchgate.net/publication/10800536 |journal= Pediatric Neurology|year=2003 |language=en |doi=10.1016/S0887-8994(02)00500-3|pmid=12699866 |last1=Ravid |first1=S. |last2=Maytal |first2=J. |volume=28 |issue=2 |pages=139–141 }}</ref>

===Shunt complications===
Examples of possible complications include shunt malfunction, shunt failure, and shunt infection, along with infection of the shunt tract following surgery (the most common reason for shunt failure is infection of the shunt tract). Although a shunt generally works well, it may stop working if it disconnects, becomes blocked (clogged) or infected, or it is outgrown. If this happens, the CSF begins to accumulate again and a number of physical symptoms develop (headaches, nausea, vomiting, [[photophobia]]/light sensitivity), some extremely serious, such as [[seizure]]s. The shunt failure rate is also relatively high (of the 40,000 surgeries performed annually to treat hydrocephalus, only 30% are a person's first surgery) and people not uncommonly have multiple shunt revisions within their lifetimes.<ref>{{Cite web | vauthors = Benner KW, Spellen S, Jeske A |title=Pharmacology of Shunt Infections |url=https://www.uspharmacist.com/article/pharmacology-of-shunt-infections |access-date=2022-05-18 |website=www.uspharmacist.com |language=en}}</ref>

Another complication can occur when CSF drains more rapidly than it is produced by the [[choroid plexus]], causing symptoms of listlessness, severe headaches, irritability, light sensitivity, auditory [[hyperesthesia]] (sound sensitivity), hearing loss,<ref name=":3" /> nausea, vomiting, [[dizziness]], [[Vertigo (medical)|vertigo]], [[migraines]], seizures, a change in personality, [[weakness]] in the arms or legs, [[strabismus]], and [[Diplopia|double vision]] to appear when the person is vertical. If the person lies down, the symptoms usually vanish quickly. A [[CT scan]] may or may not show any change in ventricle size, particularly if the person has a history of slit-like ventricles. Difficulty in diagnosing over-drainage can make treatment of this complication particularly frustrating for people and their families. Resistance to traditional [[analgesic]] pharmacological therapy may also be a sign of shunt overdrainage or failure.<ref>{{cite journal | vauthors = Nagahama Y, Peters D, Kumonda S, Vesole A, Joshi C, J Dlouhy B, Kawasaki H | title = Delayed diagnosis of shunt overdrainage following functional hemispherotomy and ventriculoperitoneal shunt placement in a hemimegalencephaly patient | journal = Epilepsy & Behavior Case Reports | volume = 7 | pages = 34–36 | date = 2017-01-24 | pmid = 28348960 | pmc = 5357741 | doi = 10.1016/j.ebcr.2016.12.003 }}</ref>

Following placement of a ventriculoperitoneal shunt there have been cases of a decrease in post-surgery hearing. It is presumed that the cochlea aqueduct is responsible for the decrease in hearing thresholds. The cochlea aqueduct has been considered as a probable channel where CSF pressure can be transmitted. Therefore, the reduced CSF pressure could cause a decrease in Perilymphatic pressure and cause secondary endolymphatic hydrops.<ref name=":3" /> In addition to the increased hearing loss, there have also been findings of resolved hearing loss after ventriculoperitoneal shunt placement, where there is a release of CSF pressure on the auditory pathways.<ref>{{cite journal | vauthors = Sammons VJ, Jacobson E, Lawson J | title = Resolution of hydrocephalus-associated sensorineural hearing loss after insertion of ventriculoperitoneal shunt | journal = Journal of Neurosurgery. Pediatrics | volume = 4 | issue = 4 | pages = 394–396 | date = October 2009 | pmid = 19795973 | doi = 10.3171/2009.4.PEDS09103 }}</ref>

The diagnosis of CSF buildup is complex and requires specialist expertise. Diagnosis of the particular complication usually depends on when the symptoms appear, that is, whether symptoms occur when the person is upright or in a prone position, with the head at roughly the same level as the feet.<ref>{{cite journal | vauthors = Krishnan SR, Arafa HM, Kwon K, Deng Y, Su CJ, Reeder JT, Freudman J, Stankiewicz I, Chen HM, Loza R, Mims M, Mims M, Lee K, Abecassis Z, Banks A, Ostojich D, Patel M, Wang H, Börekçi K, Rosenow J, Tate M, Huang Y, Alden T, Potts MB, Ayer AB, Rogers JA | display-authors = 6 | title = Continuous, noninvasive wireless monitoring of flow of cerebrospinal fluid through shunts in patients with hydrocephalus | journal = npj Digital Medicine | volume = 3 | issue = 1 | pages = 29 | date = 2020-03-06 | pmid = 32195364 | pmc = 7060317 | doi = 10.1038/s41746-020-0239-1 }}</ref>

Standardized protocols for inserting cerebral shunts have been shown to reduce shunt infections.<ref>{{cite journal | vauthors = Yang MM, Hader W, Bullivant K, Brindle M, Riva-Cambrin J | title = Calgary Shunt Protocol, an adaptation of the Hydrocephalus Clinical Research Network shunt protocol, reduces shunt infections in children | journal = Journal of Neurosurgery. Pediatrics | volume = 23 | issue = 5 | pages = 559–567 | date = February 2019 | pmid = 30797206 | doi = 10.3171/2018.10.PEDS18420 | s2cid = 73507028 }}</ref><ref>{{cite journal | vauthors = Kestle JR, Riva-Cambrin J, Wellons JC, Kulkarni AV, Whitehead WE, Walker ML, Oakes WJ, Drake JM, Luerssen TG, Simon TD, Holubkov R | display-authors = 6 | title = A standardized protocol to reduce cerebrospinal fluid shunt infection: the Hydrocephalus Clinical Research Network Quality Improvement Initiative | journal = Journal of Neurosurgery. Pediatrics | volume = 8 | issue = 1 | pages = 22–29 | date = July 2011 | pmid = 21721884 | pmc = 3153415 | doi = 10.3171/2011.4.PEDS10551 }}</ref> There is tentative evidence that preventative antibiotics may decrease the risk of shunt infections.<ref>{{cite journal | vauthors = Arts SH, Boogaarts HD, van Lindert EJ | title = Route of antibiotic prophylaxis for prevention of cerebrospinal fluid-shunt infection | journal = The Cochrane Database of Systematic Reviews | volume = 6 | pages = CD012902 | date = June 2019 | issue = 6 | pmid = 31163089 | pmc = 6548496 | doi = 10.1002/14651858.CD012902.pub2 }}</ref>