Hydrocephalus

===Exceptional case===
One case of hydrocephalus was a man whose brain shrank to a thin sheet of tissue, due to a buildup of cerebrospinal fluid in his skull. As a child, the man had a shunt, but it was removed when he was 14. In July 2007, at age 44, he went to a hospital due to mild weakness in his left leg. When doctors learned of the man's medical history, they performed a CT and MRI scan, and were astonished to see "massive enlargement" of the lateral ventricles in the skull. Dr. Lionel Feuillet of Hôpital de la Timone in [[Marseille]] said, "The images were most unusual... the brain was virtually absent."<ref>{{cite web |url=http://www.foxnews.com/story/0,2933,290610,00.html |title=Man with Almost No Brain Has Led Normal Life |archive-url=https://web.archive.org/web/20070916054402/http://www.foxnews.com/story/0,2933,290610,00.html |archive-date=2007-09-16 |publisher=Fox News |date=2007-07-25}} Also see {{cite web |url=https://www.newscientist.com/article/dn12301-man-with-tiny-brain-shocks-doctors.html |title=Man with tiny brain shocks doctors |archive-url=https://web.archive.org/web/20150712092909/http://www.newscientist.com/article/dn12301-man-with-tiny-brain-shocks-doctors.html |archive-date=2015-07-12 |work=New Scientist |date=2007-07-20}}; {{cite web |url=https://www.sciencedaily.com/releases/2007/07/070722203858.htm |title=Tiny Brain, Normal Life |archive-url=https://web.archive.org/web/20071001002639/https://www.sciencedaily.com/releases/2007/07/070722203858.htm |archive-date=2007-10-01 |work=ScienceDaily |date=2007-07-24}}</ref> Intelligence tests showed the person had an IQ of 75, considered "[[Borderline intellectual functioning]]", just above what would be officially classified as intellectually disabled.<ref>{{cite journal | vauthors = Peltopuro M, Ahonen T, Kaartinen J, Seppälä H, Närhi V | title = Borderline intellectual functioning: a systematic literature review | journal = Intellectual and Developmental Disabilities | volume = 52 | issue = 6 | pages = 419–443 | date = December 2014 | pmid = 25409130 | doi = 10.1352/1934-9556-52.6.419 }}</ref><ref>{{cite journal | vauthors = Nouwens PJ, Lucas R, Smulders NB, Embregts PJ, van Nieuwenhuizen C | title = Identifying classes of persons with mild intellectual disability or borderline intellectual functioning: a latent class analysis | journal = BMC Psychiatry | volume = 17 | issue = 1 | pages = 257 | date = July 2017 | pmid = 28716016 | pmc = 5512980 | doi = 10.1186/s12888-017-1426-8 | doi-access = free }}</ref>

The person was a married father of two children, and worked as a civil servant, leading an at least superficially normal life, despite having enlarged ventricles with a decreased volume of brain tissue. "What I find amazing to this day is how the brain can deal with something which you think should not be compatible with life", commented Dr. Max Muenke, a pediatric brain-defect specialist at the [[National Human Genome Research Institute]]. "If something happens very slowly over quite some time, maybe over decades, the different parts of the brain take up functions that would normally be done by the part that is pushed to the side."<ref>{{cite news |title=Man Lives Normal Life Despite Having Abnormal Brain |newspaper=The Globe and Mail |date=July 19, 2007 |url=https://www.theglobeandmail.com/servlet/story/RTGAM.20070719.wbrain0719/BNStory/Science/home |archive-url=https://web.archive.org/web/20070828013153/http://www.theglobeandmail.com/servlet/story/RTGAM.20070719.wbrain0719/BNStory/Science/home |archive-date=August 28, 2007 |access-date=July 15, 2012}}</ref><ref name="New Scientist Health">{{cite news |title=Man with tiny brain shocks doctors |url=https://www.newscientist.com/article/dn12301-man-with-tiny-brain-shocks-doctors.html |access-date=8 June 2013 |date=20 July 2007 |work=New Scientist and Reuters |url-status=live |archive-url=https://web.archive.org/web/20130726110907/http://www.newscientist.com/article/dn12301-man-with-tiny-brain-shocks-doctors.html |archive-date=26 July 2013}}</ref><ref name="pmid17658396">{{cite journal | vauthors = Feuillet L, Dufour H, Pelletier J | title = Brain of a white-collar worker | journal = Lancet | volume = 370 | issue = 9583 | pages = 262 | date = July 2007 | pmid = 17658396 | doi = 10.1016/S0140-6736(07)61127-1 | s2cid = 7382008 }}</ref>