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74-476: IIH can refer to: Idiopathic intracranial hypertension Innovations in International Health , an innovation platform that facilitates multidisciplinary research to develop medical technologies for developing world settings Transcription factor II H Instituto de Investigaciones Históricas ( Institute of Historical research ), a research institute of

148-478: A lumbar puncture with no specific cause found on a brain scan . Treatment includes a healthy diet, salt restriction, and exercise. The medication acetazolamide may also be used along with the above measures. A small percentage of people may require surgery to relieve the pressure. About 2 per 100,000 people are newly affected per year. The condition most commonly affects women aged 20–50. Women are affected about 20 times more often than men. The condition

222-436: A convergent squint on distance fixation. On near fixation the affected individual may have only a latent deviation and be able to maintain binocularity or have an esotropia of a smaller size. Patients sometimes adopt a face turned towards the side of the affected eye, moving the eye away from the field of action of the affected lateral rectus muscle, with the aim of controlling diplopia and maintaining binocular vision. Diplopia

296-417: A diagnosis of IIH, but do not require the actual presence of any symptoms (such as headache) attributable to IIH. These criteria also require that the lumbar puncture is performed with the person lying sideways, as a lumbar puncture performed in the upright sitting position can lead to artificially high pressure measurements. Friedman and Jacobson also do not insist on MR venography for every person; rather, this

370-412: A lack of appropriate development of the visual cortex giving rise to permanent visual loss in the suppressed eye; a condition known as amblyopia or Lazy eye . Because the nerve emerges near the bottom of the brain , it is often the first nerve compressed when there is any rise in intracranial pressure . Different presentations of the condition, or associations with other conditions, can help to localize

444-426: A person to IIH: women who are more than ten percent over their ideal body weight are thirteen times more likely to develop IIH, and this figure goes up to nineteen times in women who are more than twenty percent over their ideal body weight. In men this relationship also exists, but the increase is only five-fold in those over 20 percent above their ideal body weight. Despite several reports of IIH in families, there

518-442: A result of other conditions such as myasthenia gravis or thyroid eye disease . In children, differential diagnosis is more difficult because of the problems inherent in getting infants to cooperate with a full eye movement investigation. Possible alternative diagnosis for an abduction deficit would include: 1. Mobius syndrome - a rare congenital disorder in which both VIth and VIIth nerves are bilaterally affected giving rise to

592-606: A role in eye movements. The facial nerve (seventh cranial nerve) is affected occasionally – the result is total or partial weakness of the muscles of facial expression on one or both sides of the face. The increased pressure leads to papilledema , which is swelling of the optic disc , the spot where the optic nerve enters the eyeball . 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

666-400: A sinus lesion as all run toward the orbit in the sinus wall. Lesions in this area can arise as a result of vascular problems, inflammation, metastatic carcinomas and primary meningiomas. The VIth nerve's course is short and lesions in the orbit rarely give rise to isolated VIth nerve palsies, but more typically involve one or more of the other extraocular muscle groups. Differential diagnosis

740-492: A typically 'expressionless' face. 2. Duane syndrome - A condition in which both abduction and adduction are affected arising as a result of partial innervation of the lateral rectus by branches from the IIIrd oculomotor cranial nerve. 3. Cross fixation which develops in the presence of infantile esotropia or nystagmus blockage syndrome and results in habitual weakness of lateral recti. 4. Iatrogenic injury. Abducens nerve palsy

814-469: A unilateral softening of the brain tissue arising from obstruction of the blood vessels of the pons involving sixth and seventh cranial nerves and the corticospinal tract, the VIth nerve palsy and ipsilateral facial paresis occur with a contralateral hemiparesis. Foville's syndrome can also arise as a result of brainstem lesions which affect Vth, VIth and VIIth cranial nerves. As the VIth nerve passes through

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888-439: Is also known to occur with halo orthosis placement. The resultant palsy is identified through loss of lateral gaze after application of the orthosis and is the most common cranial nerve injury associated with this device. The first aims of management should be to identify and treat the cause of the condition, where this is possible, and to relieve the patient's symptoms, where present. In children, who rarely appreciate diplopia ,

962-405: Is different from Wikidata All article disambiguation pages All disambiguation pages Idiopathic intracranial hypertension This condition is idiopathic, meaning there is no known cause. Risk factors include being overweight or a recent increase in weight. Tetracycline may also trigger the condition. The diagnosis is based on symptoms and a high opening pressure found during

1036-411: Is no alternative explanation for the symptoms. Intracranial pressure may be increased due to medications such as high-dose vitamin A derivatives (e.g., isotretinoin for acne ), long-term tetracycline antibiotics (for a variety of skin conditions). Hormonal contraceptives , particularly the oral contraceptive pill (OCP), are not associated with IIH. A systematic review published in 2020 suggests

1110-463: Is no known genetic cause for IIH. People from all ethnicities may develop IIH. In children, there is no difference in incidence between males and females. From national hospital admission databases it appears that the need for neurosurgical intervention for IIH has increased markedly over the period between 1988 and 2002. This has been attributed at least in part to the rising prevalence of obesity, although some of this increase may be explained by

1184-512: Is only required in atypical cases (see "diagnosis" above). The primary goal in treatment of IIH is the prevention of visual loss and blindness, as well as symptom control. IIH is treated mainly through the reduction of CSF pressure and IIH may resolve after initial treatment, may go into spontaneous remission (although it can still relapse at a later stage), or may continue chronically. There are three main treatment approaches: weight loss, different medications and surgical interventions. Remission

1258-509: Is permanently deployed within the dominant transverse sinus across the stenosis under general anaesthesia. In general, people are discharged the next day. People require double antiplatelet therapy for a period of up to 3 months after the procedure and aspirin therapy for up to 1 year. In a systematic analysis of 19 studies with 207 cases, there was an 87% improvement in overall symptom rate and 90% cure rate for treatment of papilledema. Major complications only occurred in 3/207 people (1.4%). In

1332-513: Is rarely difficult in adults. Onset is typically sudden with symptoms of horizontal diplopia. Limitations of eye movements are confined to abduction of the affected eye (or abduction of both eyes if bilateral) and the size of the resulting convergent squint or esotropia is always larger on distance fixation - where the lateral recti are more active - than on near fixation - where the medial recti are dominant. Abduction limitations that mimic VIth nerve palsy may result secondary to surgery, to trauma or as

1406-416: Is seen for most patients that achieve a weight loss of around 6–10%. Bariatric surgery can be an option for those patients that don't achieve weight loss with lifestyle changes and diet. The first step in symptom control is drainage of cerebrospinal fluid by lumbar puncture. If necessary, this may be performed at the same time as a diagnostic LP (such as done in search of a CSF infection). In some cases, this

1480-450: Is sufficient to control the symptoms, and no further treatment is needed. The procedure can be repeated if necessary, but this is generally taken as a clue that additional treatments may be required to control the symptoms and preserve vision. Repeated lumbar punctures are regarded as unpleasant by people, and they present a danger of introducing spinal infections if done too often. Repeated lumbar punctures are sometimes needed to control

1554-481: Is to operate on both the lateral and medial recti of the affected eye, with the aim of stabilising it at the midline, thus giving single vision straight ahead but potentially diplopia on both far left and right gaze. This procedure is often most appropriate for those with total paralysis who, because of other health problems, are at increased risk of the anterior segment ischaemia associated with complex multi-muscle transposition procedures. Where some function remains in

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1628-411: Is typically experienced by adults with VI nerve palsies, but children with the condition may not experience diplopia due to suppression . The neuroplasticity present in childhood allows the child to 'switch off' the information coming from one eye (in this case the esotropic eye), thus relieving any diplopic symptoms. Whilst this is a positive adaptation in the short term, in the long term it can lead to

1702-592: The National Autonomous University of Mexico International Institute for Hermeneutics Topics referred to by the same term [REDACTED] This disambiguation page lists articles associated with the title IIH . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=IIH&oldid=1063693121 " Category : Disambiguation pages Hidden categories: Short description

1776-487: The cranial nerves , 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 ( third and fourth nerve palsy , respectively) are affected; both play

1850-405: The eye . The inability of an eye to turn outward, results in a convergent strabismus or esotropia of which the primary symptom is diplopia (commonly known as double vision) in which the two images appear side-by-side. Thus, the diplopia is horizontal and worse in the distance. Diplopia is also increased on looking to the affected side and is partly caused by overaction of the medial rectus on

1924-500: The glucose level, and protein levels. By definition, all of these are within their normal limits in IIH. Occasionally, the CSF pressure measurement may be normal despite very suggestive symptoms. This may be attributable to the fact that CSF pressure may fluctuate over the course of the normal day. If the suspicion of problems remains high, it may be necessary to perform more long-term monitoring of

1998-456: The otitic hydrocephalus reported by London neurologist Sir Charles Symonds may have resulted from venous sinus thrombosis caused by middle ear infection . Diagnostic criteria for IIH were developed in 1937 by the Baltimore neurosurgeon Walter Dandy ; Dandy also introduced subtemporal decompressive surgery in the treatment of the condition. The terms "benign" and "pseudotumor" derive from

2072-478: The pituitary gland due to increased pressure) and enlargement of Meckel's caves may be seen. An MR venogram is also performed in most cases to exclude the possibility of venous sinus stenosis/obstruction or cerebral venous sinus thrombosis . A contrast-enhanced MRV (ATECO) scan has a high detection rate for abnormal transverse sinus stenoses. These stenoses can be more adequately identified and assessed with catheter cerebral venography and manometry. Buckling of

2146-454: The subarachnoid space it lies adjacent to anterior inferior and posterior inferior cerebellar and basilar arteries and is therefore vulnerable to compression against the clivus . Typically palsies caused in this way will be associated with signs and symptoms of headache and/or a rise in ICP. The nerve passes adjacent to the mastoid sinus and is vulnerable to mastoiditis , leading to inflammation of

2220-415: The transverse sinuses , resulting in venous hypertension (raised venous pressure), decreased CSF resorption via arachnoid granulation and further rise in ICP. The diagnosis may be suspected on the basis of the history and examination. To confirm the diagnosis, as well as excluding alternative causes, several investigations are required; more investigations may be performed if the history is not typical or

2294-439: The 6-month period (during which observation, prism management, occlusion, or botulinum toxin may be considered), surgical treatment is often recommended. If the residual esotropia is small, or if the patient is unfit or unwilling to have surgery, prisms can be incorporated into their glasses to provide more permanent symptom relief. When the deviation is too large for prismatic correction to be effective, permanent occlusion may be

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2368-481: The FDA issued an update that gonadotropin-releasing hormone agonists, drugs that are approved for treating precocious puberty, may be a risk factor for developing pseudotumor cerebri. The cause of IIH is not known. The Monro–Kellie rule states that the intracranial pressure is determined by the amount of brain tissue, cerebrospinal fluid (CSF) and blood inside the bony cranial vault. Three theories therefore exist as to why

2442-400: The ICP by a pressure catheter. The original criteria for IIH were described by Dandy in 1937. They were modified by Smith in 1985 to become the "modified Dandy criteria". Smith included the use of more advanced imaging: Dandy had required ventriculography , but Smith replaced this with computed tomography . In a 2001 paper, Digre and Corbett amended Dandy's criteria further. They added

2516-616: The ICP urgently if the person's vision deteriorates rapidly. The best-studied medical treatment for intracranial hypertension is acetazolamide (Diamox), which acts by inhibiting the enzyme carbonic anhydrase , and it reduces CSF production by six to 57 percent. It can cause the symptoms of hypokalemia (low blood potassium levels), which include muscle weakness and tingling in the fingers. Acetazolamide cannot be used in pregnancy, since it has been shown to cause embryonic abnormalities in animal studies. Also, in human beings it has been shown to cause metabolic acidosis as well as disruptions in

2590-510: The VI nerve nucleus will not give rise to an isolated VIth nerve palsy because paramedian pontine reticular formation fibers pass through the nucleus to the opposite IIIrd nerve nucleus. Thus, a nuclear lesion will give rise to an ipsilateral gaze palsy. In addition, fibers of the seventh cranial nerve wrap around the VIth nerve nucleus, and, if this is also affected, a VIth nerve palsy with ipsilateral facial palsy will result. In Millard–Gubler syndrome ,

2664-434: The affected eye, the preferred procedure depends upon the degree of development of muscle sequelae. In a sixth nerve palsy one would expect that, over the 6 month observation period, most patients would show the following pattern of changes to their ocular muscle actions: firstly, an overaction of the medial rectus of the affected eye, then an overaction of the medial rectus of the contraletral eye and, finally, an underaction of

2738-426: The aim will be to maintain binocular vision and, thus, promote proper visual development. Thereafter, a period of observation of around 6 months is appropriate before any further intervention, as some palsies will recover without the need for surgery. This is most commonly achieved through the use of Fresnel prisms . These slim flexible plastic prisms can be attached to the patient's glasses, or to plano glasses if

2812-561: The anticonvulsant topiramate have shown some additional benefit for pain relief. The use of steroids in the attempt to reduce the ICP is controversial. These may be used in severe papilledema, but otherwise their use is discouraged. Venous sinus stenoses leading to venous hypertension appear to play a significant part in relation to raised ICP , and stenting of a transverse sinus may resolve venous hypertension, leading to improved CSF resorption, decreased ICP, cure of papilledema and other symptoms of IIH. A self-expanding metal stent

2886-404: The bilateral optic nerves with increased perineural fluid is also often noted on MRI imaging. Lumbar puncture is performed to measure the opening pressure, as well as to obtain cerebrospinal fluid (CSF) to exclude alternative diagnoses. If the opening pressure is increased, CSF may be removed for transient relief (see below). The CSF is examined for abnormal cells, infections, antibody levels,

2960-417: The blood electrolyte levels of newborn babies. The diuretic furosemide is sometimes used for a treatment if acetazolamide is not tolerated, but this drug sometimes has little effect on the ICP. Various analgesics (painkillers) may be used in controlling the headaches of intracranial hypertension. In addition to conventional agents such as paracetamol , a low dose of the antidepressant amitriptyline or

3034-455: The brain or increase in the brain tissue itself may result in the raised pressure. Little evidence has accumulated to support the suggestion that increased blood flow plays a role, but recently Bateman et al. in phase contrast MRA studies have quantified cerebral blood flow (CBF) in vivo and suggests that CBF is abnormally elevated in many people with IIH. Both biopsy samples and various types of brain scans have shown an increased water content of

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3108-483: The brain tissue. It remains unclear why this might be the case. The third theory suggests that restricted venous drainage from the brain may be impaired resulting in congestion. Many people with IIH have narrowing of the transverse sinuses . It is not clear whether this narrowing is the pathogenesis of the disease or a secondary phenomenon. It has been proposed that a positive biofeedback loop may exist, where raised ICP ( intracranial pressure ) causes venous narrowing in

3182-431: The creation of a conduit by which CSF can be drained into another body cavity. The initial procedure is usually a lumboperitoneal (LP) shunt , which connects the subarachnoid space in the lumbar spine with the peritoneal cavity . A pressure valve is usually included in the circuit to avoid excessive drainage when the person is erect. LP shunting provides long-term relief in about half the cases; others require revision of

3256-422: The decision as to which procedure is best. Optic nerve sheath fenestration is an operation that involves the making of an incision in the connective tissue lining of the optic nerve in its portion behind the eye. It is not entirely clear how it protects the eye from the raised pressure, but it may be the result of either diversion of the CSF into the orbit or the creation of an area of scar tissue that lowers

3330-510: The fact that increased intracranial pressure may be associated with brain tumors . Those people in whom no tumour was found were therefore diagnosed with "pseudotumor cerebri" (a disease mimicking a brain tumor). The disease was renamed benign intracranial hypertension in 1955 to distinguish it from intracranial hypertension due to life-threatening diseases (such as cancer); however, this was also felt to be misleading because any disease that can blind someone should not be thought of as benign, and

3404-530: The form of a squint (third, fourth, or sixth nerve palsy) or as facial nerve palsy. If the papilledema has been longstanding, visual fields may be constricted and visual acuity may be decreased. Visual field testing by automated ( 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. "Idiopathic" means of unknown cause. Therefore, IIH can only be diagnosed if there

3478-528: The increased popularity of shunting over optic nerve sheath fenestration. The first report of IIH was by the German physician Heinrich Quincke , who described it in 1893 under the name serous meningitis . The term "pseudotumor cerebri" was introduced in 1904 by his compatriot Max Nonne . Numerous other cases appeared in the literature subsequently; in many cases, the raised intracranial pressure may actually have resulted from underlying conditions. For instance,

3552-429: The largest single series of transverse sinus stenting there was an 11% rate of recurrence after one stent, requiring further stenting. Due to the permanence of the stent and small but definite risk of complications, most experts will recommend that person with IIH must have papilledema and have failed medical therapy or are intolerant to medication before stenting is undertaken. Two main surgical procedures are used for

3626-417: The lateral rectus of the unaffected eye - something known as an inhibitional palsy. These changes serve to reduce the variation in the misalignment of the two eyes in different gaze positions (incomitance). Where this process has fully developed, the preferred option is a simple recession, or weakening, of the medial rectus of the affected eye, combined with a resection, or strengthening, of the lateral rectus of

3700-433: The long-term risk of one's vision being significantly affected by IIH is reported to lie anywhere between 10 and 25%. On average, IIH occurs in about one per 100,000 people, and can occur in children and adults. The median age at diagnosis is 30. IIH occurs predominantly in women, especially in the ages 20 to 45, who are four to eight times more likely than men to be affected. Overweight and obesity strongly predispose

3774-598: The meninges, which can give rise to Gradenigo's syndrome . This condition results in a VIth nerve palsy with an associated reduction in hearing ipsilaterally, plus facial pain and paralysis, and photophobia. Similar symptoms can also occur secondary to petrous fractures or to nasopharyngeal tumours. The nerve runs in the sinus body adjacent to the internal carotid artery and oculo-sympathetic fibres responsible for pupil control, thus, lesions here might be associated with pupillary dysfunctions such as Horner's syndrome . In addition, III, IV, V1, and V2 involvement might also indicate

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3848-504: The most appropriate one can be selected for each patient. However, in patients with large deviations, the thickness of the prism required may reduce vision so much that binocularity is not achievable. In such cases it may be more appropriate simply to occlude one eye temporarily. Occlusion would never be used in infants though both because of the risk of inducing stimulus deprivation amblyopia and because they do not experience diplopia . Other management options at this initial stage include

3922-452: The name was therefore revised in 1989 to "idiopathic (of no identifiable cause) intracranial hypertension". Shunt surgery was introduced in 1949; initially, ventriculoperitoneal shunts were used. In 1971, good results were reported with lumboperitoneal shunting. Negative reports on shunting in the 1980s led to a brief period (1988–1993) during which optic nerve fenestration (which had initially been described in an unrelated condition in 1871)

3996-519: The neck and shoulders. Many have pulsatile tinnitus , a whooshing sensation in one or both ears (64–87%); this sound is synchronous with the pulse. 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 loss of coordination , are reported more rarely; none are specific for IIH. In children, numerous nonspecific signs and symptoms may be present. The increased pressure leads to compression and traction of

4070-483: The nerve in its long intracranial course, or compression against the petrous ligament or the ridge of the petrous temporal bone. Collier, however, was "unable to accept this explanation", his view being that since the sixth nerve emerges straight forward from the brain stem, whereas other cranial nerves emerge obliquely or transversely, it is more liable to the mechanical effects of backward brain stem displacement by intracranial space occupying lesions. Isolated lesions of

4144-475: The only option for those unfit or unwilling to have surgery. The procedure chosen will depend upon the degree to which any function remains in the affected lateral rectus. Where there is complete paralysis, the preferred option is to perform vertical muscle transposition procedures such as Jensen's, Hummelheim's or whole muscle transposition, with the aim of using the functioning inferior and superior recti to gain some degree of abduction. An alternative approach

4218-416: The patient has no refractive error, and serve to compensate for the inward misalignment of the affected eye. Unfortunately, the prism only correct for a fixed degree of misalignment and, because the affected individual's degree of misalignment will vary depending upon their direction of gaze, they may still experience diplopia when looking to the affected side. The prisms are available in different strengths and

4292-441: The person is more likely to have an alternative problem: children, men, the elderly, or women who are not overweight. Neuroimaging , usually with computed tomography (CT/CAT) or magnetic resonance imaging (MRI), is used to exclude any mass lesions. In IIH these scans typically appear to be normal, although small or slit-like ventricles , dilatation and buckling of the optic nerve sheaths and " empty sella sign " (flattening of

4366-491: The pressure might be raised in IIH: an excess of CSF production, increased volume of blood or brain tissue, or obstruction of the veins that drain blood from the brain . The first theory, that of increased production of cerebrospinal fluid, was proposed in early descriptions of the disease. However, there is no experimental data that supports a role for this process in IIH. The second theory posits that either increased blood flow to

4440-488: The pressure. The effects on the intracranial pressure itself are more modest. Moreover, the procedure may lead to significant complications, including blindness in 1–2%. The procedure is therefore recommended mainly in those who have limited headache symptoms but significant papilledema or threatened vision, and those who have undergone unsuccessful treatment with a shunt or have a contraindication for shunt surgery. Shunt surgery, usually performed by neurosurgeons , involves

4514-594: The reduced need for revisions in ventricular shunts, it is possible that this procedure will become the first-line type of shunt treatment. It has been shown that in obese people, bariatric surgery (and especially gastric bypass surgery ) can lead to resolution of the condition in over 95%. It is not known what percentage of people with IIH will remit spontaneously, and what percentage will develop chronic disease. IIH does not normally affect life expectancy. The major complications from IIH arise from untreated or treatment-resistant papilledema . In various case series,

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4588-441: The requirement that the person is awake and alert, as coma precludes adequate neurological assessment, and require exclusion of venous sinus thrombosis as an underlying cause. Furthermore, they added the requirement that no other cause for the raised ICP is found. In a 2002 review, Friedman and Jacobson propose an alternative set of criteria, derived from Smith's. These require the absence of symptoms that could not be explained by

4662-399: The same eye. However, where the inhibitional palsy of the contralateral lateral rectus has not developed, there will still be gross incomitance, with the disparity between the eye positions being markedly greater in the field of action of the affected muscle. In such cases recession of the medial rectus of the affected eye is accompanied by recession and/or posterior fixation (Fadenoperation) of

4736-468: The same time. Long-term untreated papilledema leads to visual loss, initially in the periphery but progressively towards the center of vision. 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

4810-409: The shunt, often on more than one occasion, usually due to shunt obstruction. If the lumboperitoneal shunt needs repeated revisions, a ventriculoatrial or ventriculoperitoneal shunt may be considered. These shunts are inserted in one of the lateral ventricles of the brain, usually by stereotactic surgery , and then connected either to the right atrium of the heart or the peritoneal cavity. Given

4884-652: The site of the lesion along the VIth cranial nerve pathway. The most common causes of VIth nerve palsy in adults are: In children, Harley reports typical causes as traumatic, neoplastic (most commonly brainstem glioma), as well as idiopathic . Sixth nerve palsy causes the eyes to deviate inward (see: Pathophysiology of strabismus ). Vallee et al. report that benign and rapidly recovering isolated VIth nerve palsy can occur in childhood, sometimes precipitated by ear, nose and throat infections. The pathophysiological mechanism of sixth nerve palsy with increased intracranial pressure has traditionally been said to be stretching of

4958-465: The treatment of IIH: optic nerve sheath decompression and fenestration and cerebral shunting . Surgery would normally only be offered if medical therapy is either unsuccessful or not tolerated. The choice between these two procedures depends on the predominant problem in IIH. Neither procedure is perfect: both may cause significant complications, and both may eventually fail in controlling the symptoms. There are no randomized controlled trials to guide

5032-429: The type of operation most appropriate for each patient. A Cochrane Review on interventions for eye movement disorders due to acquired brain injury, last updated June 2017, identified one study of botulinum toxin for acute sixth nerve palsy. The Cochrane review authors judged this to be low-certainty evidence; the study was not masked and the estimate of effect was imprecise. If adequate recovery has not occurred after

5106-425: The unaffected side as it tries to provide the extra innervation to the affected lateral rectus. These two muscles are synergists or "yoke muscles" as both attempt to move the eye over to the left or right. The condition is commonly unilateral but can also occur bilaterally. The unilateral abducens nerve palsy is the most common of the isolated ocular motor nerve palsies. The nerve dysfunction induces esotropia ,

5180-416: The use of botulinum toxin , which is injected into the ipsilateral medial rectus ( botulinum toxin therapy of strabismus ). The use of BT serves a number of purposes. Firstly, it helps to prevent the contracture of the medial rectus which might result from its acting unopposed for a long period. Secondly, by reducing the size of the deviation temporarily it might allow prismatic correction to be used where this

5254-630: The use of the term " drug-induced intracranial hypertension (DIIH) " after having applied a 'strict drug-causality algorithm' in determining IIH cases likely caused by the drugs they evaluated. There are numerous other diseases, mostly rare conditions, that may lead to intracranial hypertension. If there is an underlying cause, the condition is termed "secondary intracranial hypertension". Common causes of secondary intracranial hypertension include obstructive sleep apnea (a sleep-related breathing disorder), systemic lupus erythematosus (SLE), chronic kidney disease , and Behçet's disease . On July 1, 2022,

5328-439: Was first described in 1897. 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 any activity that further increases the intracranial pressure , such as coughing and sneezing . The pain may also be experienced in

5402-402: Was more popular. Since then, shunting is recommended predominantly, with occasional exceptions. Creutzfeldt–Jakob disease Sixth nerve palsy Sixth nerve palsy , or abducens nerve palsy , is a disorder associated with dysfunction of cranial nerve VI (the abducens nerve ), which is responsible for causing contraction of the lateral rectus muscle to abduct (i.e., turn out)

5476-419: Was not previously possible, and, thirdly, by removing the pull of the medial rectus it may serve to reveal whether the palsy is partial or complete by allowing any residual movement capability of the lateral rectus to operate. Thus, the toxin works both therapeutically, by helping to reduce symptoms and enhancing the prospects for fuller ocular movements post-operatively, and diagnostically, by helping to determine

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