Editing Idiopathic intracranial hypertension (section)

==Signs and symptoms==
The most common symptom of IIH is severe headache, which occurs in almost all (92–94%) cases. It is characteristically worse in the morning, generalized in character and throbbing in nature. It may be associated with nausea and vomiting. The headache can be made worse by [[Valsalva maneuver|any activity that further increases the intracranial pressure]], such as [[cough]]ing and [[sneeze|sneezing]]. The pain may also be experienced in the neck and shoulders.<ref name=Binder>{{cite journal |vauthors=Binder DK, Horton JC, Lawton MT, McDermott MW |title=Idiopathic intracranial hypertension |journal=Neurosurgery |volume=54 |issue=3 |pages=538–51; discussion 551–2 |date=March 2004 |pmid=15028127 |doi=10.1227/01.NEU.0000109042.87246.3C|s2cid=297003 }}</ref> Many have [[Tinnitus|pulsatile tinnitus]], a whooshing sensation in one or both ears (64–87%); this sound is synchronous with the pulse.<ref name=Binder/><ref>{{cite journal |author=Sismanis A |title=Pulsatile tinnitus. A 15-year experience |journal=American Journal of Otology |volume=19 |issue=4 |pages=472–7 |date=July 1998 |pmid=9661757}}</ref> Various other symptoms, such as numbness of the extremities, generalized weakness, pain and/or numbness in one or both sides of the face, loss of smell, and [[ataxia|loss of coordination]], are reported more rarely; none are specific for IIH.<ref name=Binder/> In children, numerous nonspecific signs and symptoms may be present.<ref name=Soler>{{cite journal |vauthors=Soler D, Cox T, Bullock P, Calver DM, Robinson RO |title=Diagnosis and management of benign intracranial hypertension |journal=Archives of Disease in Childhood |volume=78 |issue=1 |pages=89–94 |date=January 1998 |pmid=9534686 |pmc=1717437 |doi= 10.1136/adc.78.1.89|url=}}</ref>

The increased pressure leads to compression and traction of the [[cranial nerve]]s, a group of nerves that arise from the [[brain stem]] and supply the face and neck. Most commonly, the [[abducens nerve]] (sixth nerve) is involved. This nerve supplies the muscle that pulls the eye outward. Those with [[sixth nerve palsy]] therefore experience horizontal double vision which is worse when looking towards the affected side. More rarely, the [[oculomotor nerve]] and [[trochlear nerve]] ([[Oculomotor nerve palsy|third]] and [[fourth nerve palsy]], respectively) are affected; both play a role in eye movements.<ref name=Soler/><ref name=FriedmanJacobson2002>{{cite journal |vauthors=Friedman DI, Jacobson DM | year=2002 | title = Diagnostic criteria for idiopathic intracranial hypertension | journal = Neurology | volume = 59 | issue = 10 | pages = 1492–1495 | pmid = 12455560 | doi=10.1212/01.wnl.0000029570.69134.1b| s2cid=21999073 }}</ref> The [[facial nerve]] (seventh cranial nerve) is affected occasionally – the result is total or partial [[Facial nerve paralysis|weakness of the muscles of facial expression]] on one or both sides of the face.<ref name=Binder/>

The increased pressure leads to [[papilledema]], which is swelling of the [[optic disc]], the spot where the [[optic nerve]] enters the [[Human eye|eye]]ball. This occurs in practically all cases of IIH, but not everyone experiences symptoms from this. Those who do experience symptoms typically report "transient visual obscurations", episodes of difficulty seeing that occur in both eyes but not necessarily at the same time. Long-term untreated papilledema leads to visual loss, initially in the periphery but progressively towards the center of vision.<ref name=Binder/><ref name=Acheson/>

[[Neurological examination|Physical examination of the nervous system]] is typically normal apart from the presence of papilledema, which is seen on examination of the eye with a small device called an [[ophthalmoscope]] or in more detail with a [[fundus camera]]. If there are cranial nerve abnormalities, these may be noticed on [[eye examination]] in the form of a [[strabismus|squint]] (third, fourth, or sixth nerve palsy) or as facial nerve palsy. If the papilledema has been longstanding, [[visual field]]s may be constricted and [[visual acuity]] may be decreased. [[Visual field test]]ing by automated ([[Humphrey visual field analyser|Humphrey]]) perimetry is recommended as other methods of testing may be less accurate. Longstanding papilledema leads to [[optic atrophy]], in which the disc looks pale and visual loss tends to be advanced.<ref name=Binder/><ref name=Acheson>{{cite journal |author=Acheson JF |title=Idiopathic intracranial hypertension and visual function |journal=British Medical Bulletin |volume=79–80 |issue= 1|pages=233–44 |year=2006 |pmid=17242038 |doi=10.1093/bmb/ldl019 |citeseerx=10.1.1.131.9802 }}</ref>