Hydrocephalus

==Signs and symptoms==
[[File:Hydrocephalus CDC.png|thumb|400px|Illustration showing different effects of hydrocephalus on the brain and cranium]]
[[File:Gould Pyle 94.jpg|thumb|Adult showing cranial deformity from pediatric hydrocephalus]]
The clinical presentation of hydrocephalus varies with [[chronicity]]. Acute dilatation of the [[ventricular system]] is more likely to manifest with the nonspecific signs and symptoms of increased intracranial pressure (ICP). By contrast, chronic dilatation (especially in the elderly population) may have a more insidious onset presenting, for instance, with [[Hakim's triad]] (Adams' triad).<ref>{{Cite web |title=Normal_Pressure_Hydrocephalus_Hakim-Adams_Syndrome_Clinical_Symptoms_Diagnosis_and_Treatment |url=https://www.researchgate.net/publication/339884128 |website=[[ResearchGate]]}}</ref><ref>{{Cite web |title=Normal pressure hydrocephalus |url=https://www.researchgate.net/publication/11822140 |website=ResearchGate}}</ref>

Symptoms of increased ICP may include [[headache]]s, [[vomiting]], [[nausea]], [[papilledema]], [[somnolence|sleepiness]], or [[coma]]. With increased levels of CSF, there have been cases of hearing loss due to CSF creating pressure on the auditory pathways or disrupting the communication of inner ear fluid.<ref name=":1">{{cite journal | vauthors = Satzer D, Guillaume DJ | title = Hearing loss in hydrocephalus: a review, with focus on mechanisms | journal = Neurosurgical Review | volume = 39 | issue = 1 | pages = 13–24; discussion 25 | date = January 2016 | pmid = 26280639 | doi = 10.1007/s10143-015-0650-2 | s2cid = 24439157 }}</ref> Elevated ICP of different etiologies have been linked to sensorineural hearing loss (SNHL). Transient SNHL has been reported after the loss of CSF with shunt surgeries.<ref>{{cite journal | vauthors = Dixon JF, Jones RO | title = Hydrocephalus-associated hearing loss and resolution after ventriculostomy | journal = Otolaryngology–Head and Neck Surgery | volume = 146 | issue = 6 | pages = 1037–1039 | date = June 2012 | pmid = 22166958 | doi = 10.1177/0194599811431234 | s2cid = 38240969 }}</ref> Hearing loss is a rare but well-known sequela of procedures resulting in CSF loss.<ref name=":1" /> Elevated ICP may result in [[brain herniation|uncal or tonsillar herniation]], with resulting life-threatening [[brain stem]] compression.<ref name=":4">{{cite journal | vauthors = Riveros Gilardi B, Muñoz López JI, Hernández Villegas AC, Garay Mora JA, Rico Rodríguez OC, Chávez Appendini R, De la Mora Malváez M, Higuera Calleja JA | display-authors = 6 | title = Types of Cerebral Herniation and Their Imaging Features | journal = Radiographics | volume = 39 | issue = 6 | pages = 1598–1610 | date = October 2019 | pmid = 31589570 | doi = 10.1148/rg.2019190018 | s2cid = 203924869 }}</ref>

Hakim's triad of [[gait]] instability, [[urinary incontinence]], and [[dementia]] is a relatively typical manifestation of the distinct entity normal-pressure hydrocephalus. [[Focal neurological deficit]]s may also occur, such as [[abducens nerve]] palsy and vertical [[gaze palsy]] ([[Parinaud syndrome]] due to compression of the [[quadrigeminal plate]], where the neural centers coordinating the [[Conjugate eye movement|conjugated vertical eye movement]] are located). The symptoms depend on the cause of the blockage, the person's age, and how much [[brain tissue]] has been damaged by the swelling.<ref name=":4" />

In infants with hydrocephalus, CSF builds up in the central nervous system (CNS), causing the [[fontanelle]] (soft spot) to bulge and the head to be larger than expected. Early symptoms may also include:<ref name=":4" />
* Eyes that appear to gaze downward
* Irritability
* Seizures
* Separated sutures
* Sleepiness
* Vomiting

Symptoms that may occur in older children can include:<ref name=":4" />
* Brief, shrill, high-pitched cry
* Changes in personality, memory, or the ability to reason or think
* Changes in facial appearance and eye spacing (craniofacial disproportion)
* Crossed eyes or uncontrolled eye movements
* Difficulty feeding
* Excessive sleepiness
* Headaches
* Irritability, poor temper control
* Loss of bladder control ([[urinary incontinence]])
* Loss of coordination and trouble walking
* Muscle spasticity ([[spasm]])
* Slow growth (child 0–5 years)
* [[Delayed milestone]]s
* [[Failure to thrive]]
* Slow or restricted movement
* Vomiting<ref>{{cite web |vauthors=Kaneshiro NK, Zieve D, Black B, ((A.D.A.M. Editorial team)) |title=Hydrocephalus |url=https://www.nlm.nih.gov/medlineplus/ency/article/001571.htm |work=MedlinePlus}}</ref>

Because hydrocephalus can injure the brain, thought and behavior may be adversely affected. [[Learning disability|Learning disabilities]], including [[Amnesia|short-term memory loss]], are common among those with hydrocephalus, who tend to score better on verbal IQ than on performance IQ, which is thought to reflect the distribution of nerve damage to the brain.<ref name="NIH2016" /> Hydrocephalus that is present from birth can cause long-term complications with speech and language. Children can have issues such as nonverbal learning disorder, difficulty understanding complex and abstract concepts, difficulty retrieving stored information, and spatial/perceptual disorders. Children with hydrocephalus are often known in having the difficulty in understanding the concepts within conversation and tend to use words they know or have heard.<ref>{{cite journal | vauthors = Barnes MA, Dennis M | title = Discourse after early-onset hydrocephalus: core deficits in children of average intelligence | journal = Brain and Language | volume = 61 | issue = 3 | pages = 309–334 | date = February 1998 | pmid = 9570868 | doi = 10.1006/brln.1998.1843 | s2cid = 13336454 }}</ref><ref>{{Citation| vauthors = Oi S |title=Hydrocephalus Associated with Spina Bifida: Specific Pathophysiology and Therapeutic Problems|date=1999|work=Spina Bifida|pages=177–184|publisher=Springer Japan|isbn=978-4-431-70260-3}}</ref> However, the severity of hydrocephalus can differ considerably between individuals, and some are of average or above-average intelligence. Someone with hydrocephalus may have coordination and visual problems, or clumsiness. They may reach puberty earlier than the average child (this is called [[precocious puberty]]). About one in four develops [[epilepsy]].<ref>{{Cite web |title=Hydrocephalus |url=https://academic.oup.com/edrv/article/24/5/668/2424459 |access-date=2022-05-16 }}</ref>