This document provides information about idiopathic intracranial hypertension (IIH), including: - IIH most commonly affects obese women of childbearing age and is characterized by increased intracranial pressure without a known cause. - Common symptoms include headache, transient visual obscurations, and pulsatile tinnitus. Papilledema is the most important sign. - The pathogenesis is unclear but likely involves increased CSF production/decreased absorption related to obesity, sex hormones, and possibly venous sinus stenosis. - Diagnosis is based on signs of increased ICP with normal neuroimaging and lumbar puncture showing elevated opening pressure. Management focuses on weight loss and medications to reduce ICP and protect vision.

1. IDIOPATHIC INTRACRANIAL
HYPERTENSION
Dr KYAW ZAW LYNN ( MM)

2. CONTENTS
 INTRODUCTION
 PATHOGENESIS
 EPIDEMIOLOGY
 CLINICAL FEATURES
 INVESTIGATIONS
 DIFFERENTIAL DIAGNOSIS
 MANAGEMENT
 CONCLUSION

3. INTRODUCTION
 Idiopathic intracranial hypertension (IIH; formerly known as pseudotumor
cerebri or benign intracranial hypertension) -
a syndrome of increased intracranial pressure of unclear etiology that most often
occurs in obese women of childbearing age
 Diagnosis can usually be confidently made in accordance with the modified
Dandy criteria:
(1) awake and alert patient
(2) symptoms and signs of increased intracranial pressure
(3) absence of focal signs on neurologic examination (although sixth and seventh nerve palsies are
permitted)
(4) normal diagnostic studies (ie, neuroimaging and CSF evaluation), except for evidence of
increased intracranial pressure (ie, a CSF opening pressure greater than 20 cm H2O with signs
of increased intracranial pressure on neuroimaging)
(5) no other etiology for increased intracranial pressure identified

4. What’s In a Name? “Idiopathic Intracranial
Hypertension”
 IIH includes all patients with isolated raised ICP that is not related to
an intracranial process, cerebral venous thrombosis, or a meningeal
process
 The term pseudotumor cerebri should not be used, as it often
includes patients with other causes of raised ICP and is confusing
 The term benign intracranial hypertension suggests that this
disorder is benign, whereas up to 31% of patients with IIH
irreversibly lose vision

5.  Suggested that the terms primary and secondary intracranial
hypertension might be considered to describe either -
1) young obese women with isolated raised ICP and no obvious
precipitating factors
(or)
2) patients with isolated raised ICP associated with factors such
as endocrine disorders, anemia, obstructive sleep apnea, medications,
or cerebral venous sinus stenosis
 Preferred term idiopathic intracranial hypertension
( Citation from Matthew J. Thurtell, MBBS, FRACP et al ,2010)

6. PATHOGENESIS
 The pathogenesis of IIH remains poorly understood and controversial
 A variety of mechanisms have been proposed, including -
-blockage of CSF absorption at the level of the arachnoid villi
-consequence of or exacerbated by cerebral venous hypertension
secondary to transverse venous sinus stenosis
 Increased incidence in women
 Strong association with obesity, sex hormones (eg, androgens) and adipose
tissue

7.  Theories include -
-increased brain water content,
-excess CSF production,
-reduced CSF absorption
-increased cerebral venous pressure
 Underlying endocrine dysfunction related to sex hormones and adipose tissue as
an actively secreting endocrine organ has also been proposed
 A great controversy exists regarding the role of cerebral venous hypertension in
the etiology of IIH

8. Older studies suggested that increased ICP might be a direct result of
 Increased intra-abdominal pressure, via elevation of the diaphragm,
 Raised pleural pressure
 Decreased cerebral venous return
 Sustained cerebral venous hypertension

9.  Numerous recent reports discussing the role of transverse venous sinus stenoses in the
pathophysiology of IIH
 Because CSF drains passively into the venous sinuses, a stenosis of a dominant transverse
sinus or stenoses of both transverse sinuses could reduce venous outflow, resulting in
cerebral venous hypertension and impaired CSF resorption
( Citation from Matthew J. Thurtell, MBBS, FRACP et al ,2010)
Increased ICP
Decreased CSF Absorption
Venous Outflow Obstruction
Transverse Venous
Sinus Stenosis
Venous Hypertension
Figure 5. Schematic summary of the presumed role of
transversevenous sinus stenosisin idiopathicintracranial
hypertension. CSF, cerebrospinal fluid; ICP, intracranial
pressure.

10.  Obesity is strongly related to the development of IIH
 Adipose tissue has been increasingly viewed as a neuroendocrine tissue releasing chemical
signals, in particular adipokines such as leptin,
 Could act directly on the choroid plexus or arachnoid granulation tissue, (or)
indirectly via peripheral mechanism with consequent secondary central effects that
modify CSF secretion and absorption
 Obese state is also an inflammatory condition where chronically increased circulating or CSF
cytokines may result in fibrotic changes or lead to hypercoagulable state
blockage of the arachnoid granulations reducing drainage of CSF
( Citation from Damkier HH, Brown PD, Praetorius J,2015)

11.  A larger study (n=51) that assessed the hormone profile of female
IIH patients demonstrated no difference in the levels of estradiol,
follicular-stimulating hormone, luteinizing hormone, or prolactin
 The study did show raised levels of androgens, including
testosterone and androstenedione, in young onset (25 years of age)
female patients with IIH
( Citation from O’Reilly MW, Taylor AE, Crabtree NJ, et al,2014)
 Between 39% and 57% of IIH patients also suffer from polycystic
ovarian syndrome (PCOS), which is characterized by androgen
dysregulation
( Citation from Glueck CJ, Aregawi D, Goldenberg N, Golnik KC, Sieve L, Wang P, 2005)

12. EPIDEMIOLOGY
 IIH most commonly occurs in obese women of childbearing age
 The incidence of IIH is variable, being higher in geographic areas that have a
higher prevalence of obesity
 The incidence increased to 22 per 100,000 in obese women aged
15 to 44
 A high body mass index (BMI) was found to be associated with increased risk of
IIH
 Study found that greater levels of weight gain were associated with an increased
risk of IIH
 Increased risk of IIH also existed in women who were not obese (BMI <30) in
the setting of moderate weight gain

13. EPIDEMIOLOGY ( cont)
 IIH can also occur in men, children, and older adults
 A 2017 study reported that the annual incidence of IIH in Minnesota
was 0.3 per 100,000 in men compared to 3.3 per 100,000 in women
 IIH also occurs in children but is not common
 In a 2017 British study, the annual incidence of IIH in children and
adolescents (aged 1 to 16 years) was 0.71 per 100,000
 The incidence increased to 4.18 per 100,000 in obese males aged 12
to 15 years and 10.7 per 100,000 in obese females aged 12 to 15
years

14.  A recent study showed that black patients with IIH were 3 times
more likely than other patients to have severe visual loss in at least
one eye and were nearly 5 times more likely to be blind in both eyes
(Citation from Bruce BB, Preechawat P, Newman NJ, et al,2008)
 It has recently been shown that men with IIH are more likely than
matched control subjects to have symptoms associated with
testosterone deficiency and obstructive sleep apnea
(Citation from Fraser JA, Bruce BB, Rucker J, et al, 2010)

15. CLINICAL FEATURES
 Patients with IIH usually present with symptoms and signs of increased
intracranial pressure
 Common symptoms
 Headache
 Transient visual obscurations
 Pulse-synchronous (pulsatile) tinnitus
 Common signs
Papilledema with or without associated retinal hemorrhages, folds,
cotton wool spots, and exudates

16. Headache
 The most common symptom of IIH
 In the Idiopathic Intracranial Hypertension Treatment Trial, 84% of participants
had headache at presentation
 Typically a global headache that is most severe in the morning and is often
aggravated by maneuvers with associated nausea and vomiting
 Many patients with IIH have headaches with features of other headache
disorders, such as migraine and tension headache
 Some have a significant rebound component to their headache due to excessive
use of simple analgesic medications

17. Headache ( cont)
 Although headache is often disabling and associated with poor
quality of life,
 headache disability is not correlated with CSF opening pressure
 Headache may or may not improve with lowering of intracranial
pressure

19. Transient visual obscurations (TVOs)
 Occur in about 68% of patients with IIH
 Characterized by a partial or complete loss of vision
- lasts for several seconds,
- followed by a rapid recovery of vision
 Occur many times per day
 Precipitated by postural changes or Valsalva-like maneuvers
 Due to result from transient ischemia of the edematous optic nerve
head

20.  Associated with higher grades of papilledema
 a predictor of treatment failure in the Idiopathic Intracranial Hypertension Treatment Trial
 Some have blurred vision due to
 hyperopic shift (from shortening of the globe due to increased ICP)
(or)
 metamorphopsia (distortion of vision) due to retinal folds
 Notice an enlarged blind spot, many do not notice visual field loss
 Consequently, the visual field loss from papilledema can go unnoticed until it
is severe and irreversible,
 Underscoring the importance of perimetry (visual field testing) in the
evaluation and monitoring of patients with IIH

21. Pulse-synchronous (pulsatile) tinnitus
 Occurs in about 52% to 60% of patients
 Can be unilateral or bilateral
 It is frequently intermittent, it can also be continuous
 Can be decreased with ipsilateral jugular compression
resolves following stenting of transverse venous sinus stenoses
 Arises because of turbulent blood flow across stenoses in the
transverse venous sinuses

22. Less common symptoms in IIH
 Diplopia due to unilateral or bilateral sixth nerve palsy, with
moderate to severe disease
 Up to 25% of patients are asymptomatic, with papilledema being
discovered during a routine eye examination

23. Papilledema
 Papilledema (optic disc edema secondary to increased intracranial
pressure) is the most common and important sign in IIH
 Is usually bilateral and symmetric , although occasional patients
have highly asymmetric papilledema
 Is a result of axoplasmic flow stasis secondary to increased
intracranial pressure, producing edema of the retinal nerve fibers
emanating from the optic disc
 Threat of vision loss is correlated with the severity of papilledema
 If untreated, papilledema can result in progressive and irreversible
vision loss with optic atrophy

24.  The severity of papilledema can be graded based on the appearance of
the optic disc using the modified Frisén scale
 Grade I (minimal papilledema) is characterized by a C-shaped halo
with sparing of the temporal margin of the optic disc
 Grade II (mild papilledema) is characterized by a circumferential
halo
Appearance of papilledema of increasing severity, graded using the modified Frisén scale

25.  Grade III (moderate papilledema) is characterized by obscuration of at least one segment of a
major blood vessel leaving the optic disc
 Grade IV (marked papilledema) is characterized by total obscuration of a segment of a major
blood vessel on the optic disc
 Grade V (severe papilledema) is characterized by total obscuration of all blood vessels on and
leaving the optic disc
Appearance of papilledema of increasing severity, graded using the modified Frisén scale

27.  Hemorrhages in the peripapillary retinal nerve fiber layer commonly occur in
association with papilledema
 Correlated with the severity of papilledema
FIGURE 5-2
Peripapillary hemorrhages occurring in
association with papilledema include
flame-shaped retinal nerve fiber layer
hemorrhages (A) and
subretinal hemorrhages (B).
Occasionally, extensive subretinal
hemorrhage may be seen
secondary to peripapillary choroidal
neovascularization (C).

28.  Retinal folds can often be detected with careful observation; the folds may be
circumferential around the optic disc
FIGURE 5-3
Peripapillary retinal folds occurring in association with papilledema include circumferential
folds around the optic disc (A, arrowheads) and
radial folds extending into the macula (B, arrows).

29.  Cotton wool spots (retinal nerve fiber layer infarcts) and retinal exudates can also be
present, especially with more severe grades of papilledema
 Pseudodrusen are small white refractile deposits overlying the optic disc that can
develop in patients with long-standing papilledema
FIGURE 5-4 Cotton wool spots (retinal nerve fiber layer infarcts) and retinal exudates can develop with
more severe degrees of papilledema (A). Small white refractile deposits overlying the optic
disc, known as pseudodrusen, can occasionally develops with chronic severe papilledema (B).

31.  Papilledema can be rapidly progressive with a fulminant presentation,
 resulting in early and sometimes irreversible central vision loss
 Formal perimetry (visual field testing) is mandatory in the evaluation and
monitoring of patients with IIH
 Patients with mild papilledema (less than grade II) might have no visual field
defects on automated perimetry
 An enlarged physiologic blind spot is the first visual field defect to develop
papilledema
 The enlarged blind spot is a refractive scotoma resulting from peripapillary
hyperopia

32.  With increasing severity and duration of papilledema
- arcuate visual field defects can develop
(initially in the inferonasal portion of the visual field)
 With more severe or long-standing papilledema
- the visual field becomes progressively constricted
(with sparing of the central visual field until late)
 Non -physiologic visual field constriction can occur with coexisting organic visual
field loss
 such constriction can result from a poor performance in a patient having difficulty
concentrating or staying awake during the test
 giving a characteristic cloverleaf appearance on automated perimetry

33. Other examination findings in IIH include-
 unilateral or bilateral sixth nerve palsy (an esotropia with limitation of abduction)
 other ocularmotility deficits (eg, third nerve palsy, fourth nerve palsy, and skew
deviation) can rarely occur
 Occasional patients have a facial nerve palsy at presentation
 Rare patients - normal optic discs (ie, no papilledema)
- have symptoms and imaging findings suggesting increased ICP &
- an increased CSF opening pressure
 Papilledema might not develop or could resolve
because of the presence of a CSF leak (eg, causing CSF rhinorrhea or otorrhea)

34. Update on Associated Conditions
 Precipitate or worsen IIH, including –
 Various medications (eg, tetracycline and its derivatives, cyclosporine, lithium,
nalidixic acid, nitrofurantoin, oral contraceptives, levonorgestrel, danazol, and
tamoxifen)
 Endocrine abnormalities (eg, corticosteroid withdrawal, anabolic steroids, excessive
growth hormone, and thyroid disease)
 Vitamin A excess or deficiency
 Systemic conditions (eg, pregnancy, menstrual irregularities, polycystic ovarian
syndrome, anemia, and obstructive sleep apnea)
( Citation from Matthew J. Thurtell, MBBS, FRACP et al, 2010)

35. INVESTIGATIONS
 Further investigations are obtained for two broad purposes-
 First, neuroimaging and CSF evaluation are required to
exclude other etiologies of increased intracranial pressure
 Second, ophthalmic investigations should be obtained to
determine the severity of vision loss and papilledema to help
management

36. Neuroimaging
 The first step in the evaluation of increased intracranial pressure
 Most structural causes of increased ICP can be identified on MRI of the
brain with contrast
 Magnetic resonance venography (MRV) of the head with contrast
-to exclude cerebral venous sinus thrombosis, especially in atypical or fulminant
presentation for IIH

37.  An empty sella turcica is a common finding
 Can also be present in the absence of increased intracranial pressure
 Dilation and increased tortuosity of the optic nerve sheaths may be seen
as well as posterior globe flattening
 The swollen optic discs may be visible and enhancing
 In some patients, acquired cerebellar tonsillar descent below the level of the
foramen magnum is seen
 Can be mistaken for a (congenital) Chiari malformation

38.  MRI findings suggesting increased intracranial pressure.
 A, Sagittal T1-weighted MRI showing an empty sella turcica with mild inferior cerebellar tonsillar descent.
 B, Axial T2-weighted MRI showing dilated and tortuous optic nerve sheaths with posterior globe flattening.
 C, Axial T1-weighted postcontrast MRI showing enhancing optic discs (arrowheads).

39.  MRV of the head often shows smoothly tapered stenoses in the transverse venous
sinuses
 Result from mechanical compression of the venous sinus in the setting of increased ICP
 Less commonly, stenoses can result from intrinsic factors, such as arachnoid
granulations, septations, and organized thrombus
 Catheter venography with manometry shows a pressure gradient across stenoses, with
increased venous pressures in the superior sagittal sinus and transverse venous sinuses
proximal to the stenosis
 Stenoses might play a role in the pathogenesis of IIH or exacerbate
 Transverse venous sinus stenting has been proposed as a potential surgical
treatment for the disease

40.  Lateral (A) and frontal (B) reconstructions of magnetic resonance venography (MRV) of the head
with contrast demonstrating bilateral transverse venous sinus stenoses (arrowheads)

41.  Empty sella turcica is one of the most common imaging signs
seen in up to 70% of patients
( Citation from Brodsky MC, Vaphiades M.1998)
 To be a normal variant, seen in up to 12% of asymptomatic
individuals, presumably the result of deficiency in the diaphragm sella
( Citation from Saindane AM, Lim PP, Aiken A, Chen Z, HudginsPA,2013)
 Most MRI signs have overall high specificity but low sensitivity in
diagnosing intracranial hypertension
 Transverse sinus stenosis appears to be the most useful sign, because
high specificity and high sensitivity
( Citation from Robert M Kwee, European journal of radiology , vol 116,2019)

42. CSF Evaluation
 Lumbar puncture has a dual role in the diagnosis of IIH -
 First, to confirm the presence of an increased CSF opening pressure
 Second, to evaluate of the CSF constituents to exclude other etiologies
(eg, infectious, inflammatory, or neoplastic and meningitis)
 Lumbar puncture should be obtained with the patient positioned in the left lateral
recumbent position
 CSF opening pressure should be measured with
-legs extended,
-head in a neutral position,
-patient breathing normally

43.  Normal CSF opening pressure in adults is 10 cm H2O to 20 cm H2O
 greater than 25 cm H2O is considered high,
 pressure of 20 cm H2O to 25 cm H2O is considered borderline,
 Recent studies have found that
 normal range for CSF opening pressure in children is higher than in adults
 less than 28 cm H2O is considered normal in children

44. CSF Evaluation
 CSF opening pressure can be influenced by a number of factors
 incorrect positioning of the patient or
 manometer during the opening pressure measurement and
 use of sedation during the procedure
 CSF constituents should be normal
 Presence of an increased white cell count or protein concentration should raise
concern for another etiology of increased intracranial pressure

45. Ophthalmic Investigations
 Formal perimetry is mandatory for evaluation and monitoring
 Other investigations, such as fundus autofluorescence and ultrasonography
 helpful in the evaluation of suspected pseudopapilledema
 OCT (Optical Coherence Tomography)- have a role in quantifying the severity of
papilledema
 Retinal nerve fiber layer thickness correlates well with papilledema severity
especially for lower grades of papilledema
 OCT measures of retinal nerve fiber layer thickness must be interpreted with
caution
 Combined retinal nerve fiber layer edema and atrophy might give a retinal nerve
fiber layer thickness that appears to be close to normal despite significant visual
field loss from optic nerve damage

48.  OCT show thinning of the retinal ganglion cell and inner plexiform layer
complex (containing the cell bodies for retinal nerve fibers)
 Correlates well with the severity of vision loss secondary to optic nerve damage
 High-resolution raster scans obtained through the optic nerve head using OCT
- demonstrate biomechanical changes correlate with increased ICP
- an inward deflection of the peripapillary retinal pigment epithelium and Bruch
membrane complex toward the vitreous of the eye

49.  Optical coherence tomography showing diffuse
retinal nerve fiber layer (RNFL) edema in a
patient with grade II papilledema (A).
 The peripapillary RNFL thickness in
micrometers (μm) is determined
after segmentation of the retinal layers (B,
purple circle).
 The peripapillary RNFL thickness of the
right eye (OD, solid line) and left eye (OS,
dashed line) can be plotted and compared to an
age-matched normal dataset et).

50.  (C, shaded green area indicates the 95%
confidence limits of RNFL thickness for the age-
matched normal data
 The RNFL quadrant analysis indicates the average
RNFL thickness for the superior (S), nasal (N),
inferior (I), and temporal (T) quadrants (D)
 The average RNFL thickness for this patient was
218 μm for the right eye and 177 μm for the left
eye (normal range is about 80 to 100 μm)

51. High-resolution raster scans obtained using optical coherence tomography through the optic
nerve head (A, blue line) can show inward deflection of the retinal pigment epithelium and
Bruch membrane complex toward the vitreous cavity (B, arrowheads) when increased
intracranial pressure is present.

52. DIFFERENTIAL DIAGNOSIS
 Several etiologies of increased ICP can mimic IIH
 Several medications
 mimics IIH,
 precipitate or worsen preexisting IIH
 Include
- tetracycline antibiotics (eg, minocycline)
- retinoids (eg, vitamin A derivatives and all-trans retinoic acid)
- lithium
 Corticosteroid withdrawal -cause rebound intracranial
hypertension

54.  Optic disc drusen can be mistaken for
papilledema. With buried optic disc drusen
(A),
 The optic disc drusen are located beneath
the surface of the disc and are not visible
on funduscopic examination; the optic disc
is often elevated and can have an
appearance that can be difficult to
distinguish from mild papilledema.
 When optic disc drusen become exposed,
they are yellow in color and refractile, with
a “rock candy” appearance (B).
 Since exposed optic disc drusen display
autofluorescence, they are often prominent
on fundus autofluorescence (C).
 Buried optic disc drusen may not be
visible on fundus autofluorescence but can
usually be detected on ultrasonography (D)
as a focus of increased reflectivity within
the elevated optic nerve head (arrowheads)
with a characteristic posterior reduplication
artifact (arrows )

55.  Cerebral venous hypertension due to
-cerebral venous sinus thrombosis,
-extrinsic venous sinus compression (eg, by a meningioma), or
-arterialization of the sinus by a dural arteriovenous fistula
can cause a clinical syndrome that mimics IIH

57. MANAGEMENT
 The two main goals of treatment –
 To preserve visual function and
 To alleviate symptoms
 Many treatment approaches have been proposed for IIH, including
1. lifestyle interventions (weight loss)
2. medical therapies
3. surgical interventions

58. Weight Loss
 Studies suggest
- weight loss of about 6% to 10% of initial body weight
- adequate to induce remission in most patients with IIH
 In a 2010 prospective cohort study,
- a low-calorie diet resulted in a significant reduction in CSF
opening pressure, papilledema, and headache disability

59. While effective in the long term,
 not a practical or effective treatment in the short term;
 other treatments must be initiated in parallel for most patients with IIH
 Bariatric surgery is an option for patients who are morbidly obese whose
weight loss attempts have been unsuccessful,
 Visual outcomes from bariatric surgery have not been studied

60. Medical Therapy
Carbonic anhydrase inhibitors
 such as acetazolamide and methazolamide,
 mainstay of medical therapy for IIH
 To decrease CSF production, mild diuretic effect
 Dose was titrated up, as tolerated, to a maximum of 2000 mg 2 times a day
 Primary outcome measure was change in mean deviation
 Secondary outcome measures included improving
 changes in papilledema grade
 symptoms
 quality of life
 weight control

61.  Acetazolamide was well tolerated
 Common side effects included paresthesia, dysgeusia, nausea, vomiting, and diarrhea
 Dosage increases may be limited due to dose-dependent side effects
 The risk factors for treatment failure included
i. male sex
ii. higher papilledema grade (ie, grades III–V)
iii. decreased visual acuity at presentation
iv. greater than 30 transient visual obscurations per month
v. peripapillary retinal nerve fiber layer hemorrhages at presentation
 such patients require closer monitoring and may need more aggressive treatment
 Most patients with IIH and mild vision loss seem to respond well to doses of
500 mg to 1000 mg 2 times a day
 optimum acetazolamide dose for patients with moderate to severe vision loss at presentation
remains unclear, although many clinicians rapidly titrate up to high doses (eg, 1500 mg to 2000
mg 2 times a day), as tolerated, before considering surgical interventions

62.  Contraindications known hypersensitivity, including sulfur allergy
 Contraindicated in patients with liver failure, due to the increased risk of producing
hepatic encephalopathy
 Directly results from increased cerebral tissue carbon dioxide tensions and respiratory
alkalosis in advanced liver disease
 Relatively contraindicated in patients with a history of renal stones
 Category C drug in pregnancy, although two studies suggest that it is safe to use during
the second and third trimesters of pregnancy in IIH patients
(Citation from Lee AG, Pless M, Falardeau J, et al,2005)

63. Topiramate
 is used for treatment of primary headache disorders (migraine)
 a weak carbonic anhydrase inhibitor
 similar efficacy to acetazolamide in treating patients with mild to moderate IIH
 often causes weight loss
 considered - when acetazolamide cannot be tolerated
- when headache is prominent
 low doses of 25 mg/d to 50 mg/d
 titrated up to 100 mg 2 times a day for improved symptom control
 better tolerated than acetazolamide
 common side effects include mental slowing, lethargy, paresthesia, decreased appetite
 Other important, but less common, side effects include
-renal stones
-acute angle-closure glaucoma

64.  A randomized open-label study has shown that topiramate and acetazolamide have
similar beneficial effects at 12 months in IIH patients,
 But further controlled studies are required to confirm these findings
( Citation from Celebisoy N, Gökçay F, Sirin H, Akyürekli O,2007)

65.  Other diuretics, such as furosemide( 20mg or 40mg once or twice daily)
 alone or in combination with other medications for a synergistic effect
 monitoring of electrolytes and potassium supplementation is required
 Corticosteroids were used for treatment in the past but produce undesirable long-term
complications, such as weight gain
 Corticosteroid withdrawal can result in a rebound increase ICP
 High-dose IV corticosteroids
 used for the short-term treatment
 patients who have a fulminant presentation
 while awaiting definitive surgical intervention (eg, CSF shunting)
 Methylprednisone can be given at a dose of 1g per day
( Citation from Matthew J. Thurtell, MBBS, FRACP,2013)

66. Bumetanide (Bumex)
 To inhibit the mechanism of glial cell volume regulation
 Inhibition of Na+-K+-2Cl- cotransport
 Help in the treatment IIH by reducing glial cell volume, instead of CSF volume
 Resolution of the patient’s headaches, papilledema and
 Normalization of visual fields in a patient with IIH
 Low-dose bumetanide (0.25mg daily) - effective
-by restoring the balance between CSF formation and absorption
-by altering the volume or ionic composition of the brain’s extracellular compartment
(Citation from Binder DK, Horton JC, Lawton MT et al, 2004)

67. Surgical Therapies
 Surgical intervention -for patients with a fulminant presentation of IIH
 Needed in those who fail to improve or worsen despite maximally tolerated
medical therapy
 The three most commonly used interventions are -
 CSF shunting
 Optic nerve sheath fenestration
 Transverse venous sinus stenting

68. CSF shunting
 very effective for rapidly reducing intracranial pressure and papilledema
 Stereotactic ventriculoperitoneal shunting is preferred over lumboperitoneal shunting
because of its lower complication rate
 Incorporation of an adjustable valve into the shunt apparatus allows the CSF flow rate to
be adjusted according to symptoms and signs
 Significant complication rate, including -
 Infection
 Obstruction
 Migration of shunt tubing
 shunt revisions are often needed

69.  Not be considered for the management of isolated intractable headache unless
- the headache is known to respond to decreases in intracranial pressure
(eg,following a lumbar puncture)
- noninvasive management options have been ineffective
 One large retrospective study found that
- headache initially improved in most patients with IIH following CSF shunting,
- almost 50% had recurrent headaches at 36 months following CSF shunting

70. Optic nerve sheath fenestration
 Effective intervention to consider when vision is threatened
 A superior or medial orbital approach is used
- to create slits or a window in the retrolaminar optic nerve sheath
- creating a fistula between the subarachnoid space and orbital cavity
 Decrease in pressure on the optic nerve results in reduced papilledema with improved
visual function
 Unilateral optic nerve sheath fenestration improves the papilledema and
visual function on the contralateral side
 Many patients will require bilateral sequential optic nerve sheath fenestrations

71.  Complications of optic nerve sheath fenestration include-
 Transient or persistent vision loss (eg, from optic nerve trauma)
 Tonic pupil (eg, from damage to the ciliary ganglion or postganglionic
parasympathetic fibers)
 Diplopia

72. Transverse venous sinus stenting
 Surgical intervention to consider in patients who have
- transverse venous sinus stenoses with pressure gradients (>8 mm Hg)
across the stenoses
- increased venous pressures in the superior sagittal sinus and venous sinuses
proximal to the stenosis
 Stenting will -Reduce cerebral venous hypertension,
-Increase CSF absorption,
-Reduce intracranial hypertension
-Improve symptoms and signs
 Potential complications include -
 In-stent thrombosis
 Subdural hemorrhage
 Development of recurrent stenoses immediately proximal to the stent

73. Choice of surgical intervention
 remains controversial
 varies depending on local resources or practices
Patient’s symptoms and signs should be considered in the decision-making process
 For example, a patient who has papilledema and vision loss without other
symptoms and signs of increased intracranial pressure might be best treated
with an optic nerve sheath fenestration
 Patient with severe symptoms (eg, headache), papilledema with vision loss,
and other signs (eg, sixth nerve palsy) might be best treated with
CSF shunting

74. Summary of Management Approach
Depends on-
 severity of their vision loss based on formal perimetry
 severity of papilledema based on Frisén grade
 severity of symptoms
 response to medical therapy and ability to tolerate medical therapy

75.  Patients with minimal vision loss (mean deviation better than –3 dB)
-weight loss alone (low-calorie and low-sodium diet plus exercise),
-medical therapy can be added depending on the severity of symptoms and
response to weight-loss attempts
 Patients with mild vision loss (mean deviation of –3 dB to –7 dB)
-weight loss plus medical therapy

76.  Patients with moderate vision loss (mean deviation of –7 dB to –15 dB)
-weight loss plus more aggressive medical therapy,
-surgical intervention could be considered depending on the response to
weight loss and medical therapy
 Patients with severe vision loss (mean deviation worse than –15 dB)
-combination of weight loss plus
aggressive medical therapy plus
surgical intervention
 Timing and choice of surgical intervention remains controversial

77.  Patients with IIH require long-term monitoring
 Co-management with an ophthalmologist or neuro-ophthalmologist is crucial,
 the timing of follow-up tailored according to -
 the severity of symptoms and signs at presentation
 response to treatment
 subsequent clinical course

78. CONCLUSION
 IIH is a syndrome of increased intracranial pressure of unclear etiology
 most often occurs in obese women of childbearing age
 Recent studies have found that the annual incidence of IIH is increasing in parallel with
obesity rates
 Common symptoms of IIH include
-headache ( 84 %)
-transient visual obscurations (68 %)
-pulse-synchronous (pulsatile) tinnitus (52-60%)
 Papilledema - most common and important clinical sign
 Hemorrhages , Retinal folds , Cotton wool spots ,Retinal exudates and pseudodrusen
related severity of papilledema

79.  If untreated, it can result progressive and irreversible vision loss with optic atrophy
 underscoring the importance of funduscopic examination and formal visual field
testing (perimetry) for the monitoring of IIH
 Management options include
-weight loss
-medical therapy (eg, acetazolamide or topiramate)
-surgical interventions (eg, CSF shunting, optic nerve sheath fenestration, or
transverse venous sinus stenting)

80. The management approach should be tailored for each patient according to
1. the severity of vision loss
2. severity of papilledema
3. severity of symptoms
4. response to medical therapy
5. ability to tolerate medical therapy

81. CASE 5-1 A 23-year-old woman with a normal body mass index had a motor vehicle accident resulting in a head
injury without loss of consciousness.
 She subsequently developed severe headaches, transient visual obscurations, and pulse-synchronous
tinnitus. Her eye care provider noted bilateral papilledema.
 MRI of her brain with contrast was reported to be unremarkable. Subsequent lumbar puncture showed a
CSF opening pressure of 32 cm H2O with normal CSF constituents. Thus, she was diagnosed with
idiopathic intracranial hypertension and started on acetazolamide 1000 mg 2 times a day.
 She presented for a second opinion because of worsening of her papilledema on treatment. On examination,
her visual acuity was 20/15 in both eyes. Her pupils were equal and briskly reactive without a relative
afferent pupillary defect. Ocular motility was normal.
 Funduscopic examination showed grade IV optic disc edema in the right eye and grade III optic disc
edema in the left eye. Visual fields showed an enlarged blind spot in both eyes.
 However, a repeat MRI of her brain with contrast and magnetic resonance venography (MRV) of her head
with contrast showed superior sagittal venous sinus thrombosis with left parietal venous infarction.
 She was admitted for anticoagulation, and her acetazolamide dose was increased to 1500 mg 2 times a day.
Her symptoms and signs eventually resolved, and the acetazolamide dose was gradually decreased over
months.

82. COMMENT
 This case highlights the importance of considering cerebral venous
sinus thrombosis in a patient with increased intracranial pressure but
an atypical presentation for idiopathic intracranial hypertension.

83. CASE 5-2
 A 15-year-old girl presented with headaches and transient visual obscurations in both eyes. She reported weight gain
of 11.3 kg (25 lb) over 12 months. Her local eye care provider noted bilateral papilledema and referred her to a
pediatric neurologist for further evaluation.
 MRI of her brain with contrast and magnetic resonance venography (MRV) of her head with contrast showed signs
suggesting increased intracranial pressure but no cause for it.
 Subsequent lumbar puncture showed a CSF opening pressure of 27 cm H2O with normal CSF constituents.
 Based on these findings, she was felt to have idiopathic intracranial hypertension and was started on acetazolamide
500 mg 2 times a day.
 The patient’s parents requested a second opinion regarding the diagnosis. At the time of evaluation, the patient’s visual
acuity was 20/20 in both eyes.
 Her pupils were equal and briskly reactive without a relative afferent pupillary defect. Ocular motility was normal.
Funduscopic examination showed grade II optic disc edema in both eyes.
 Visual fields showed an enlarged blind spot in both eyes.
 Further history revealed that the patient had been started on doxycycline for acne 1 month before the onset of her
symptoms. The doxycycline was discontinued
 Acetazolamide was continued until her symptoms and signs had fully resolved.
 The patient had no recurrence of symptoms or signs after the acetazolamide was discontinued.

84. COMMENT
 This case highlights the importance of a thorough review of
medication use in the evaluation of a patient with suspected
idiopathic intracranial hypertension.

85. THANK YOU FOR YOUR ATTENTION