IIH-DIAGNOSIS&TREATMENT

1. Idiopathic intracranial hypertension

2. • Idiopathic intracranial hypertension (IIH), sometimes
called by the older names benign intracranial
hypertension (BIH) or pseudotumor cerebri (PTC),
• characterized by an increased intracranial pressure in
the absence of a tumor or other diseases.
• The main symptoms are headache, nausea and
vomiting as well as pulsatile tinnitus , double vision
and visual symptoms. If untreated, it may lead to vision
loss due to associated swelling of the optic disc in the
eye.

3. Pathophysiology
• 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 vault.
Three theories therefore exist as to why 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.
• A second theory posits that either increased blood flow to the brain or increase in
the brain tissue itself may result in the raised pressure. Little evidence has
accumulated , but both biopsy samples and various types of brain scans have
shown an increased water content of the brain tissue.
• A third theory suggests that blood flow from the brain may be impaired or
congested. Only in a small proportion of patients has underlying narrowing of the
cerebral sinuses or veins been demonstrated. Congestion of venous blood may
result from a generally increased venous pressure, which has been linked to
obesity.

5. • occurs in women who are overweight.
• The role of obesity in this disorder is unclear.
• Obesity has been proposed to increase intra-abdominal
pressure, which, in turn, raises cardiac filling pressures.
• This rise in pressure leads to impeded venous return
from the brain (due to the valveless venous system that
exists from the brain to the heart) with a subsequent
elevation in intracranial venous pressure.
• If not treated appropriately, chronic interruption of the
axoplasmic flow of the optic nerves with ensuing
papilledema due to this pressure may lead to
irreversible optic neuropathy.

6. Epidemiology
• 1 per 100,000 people,
• can occur in children and adults.
• The median age at diagnosis is 30.
• IIH occurs predominantly in women, especially in the ages 20–45, who are
four to eight times more likely than men to be affected.
• Overweight and obesity strongly predispose 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 fivefold in
those over 20% above their ideal body weight.
• Despite several reports of IIH in families, there 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.

7. Causes
• Most cases of idiopathic intracranial hypertension
occur in young women who are obese and, less
frequently, in men who are otherwise healthy. Patients
with higher body mass indexes and recent weight gain
are at an increased risk for this disorder.
• If this disorder presents in an individual who is not
overweight, ruling out associated risk factors is
necessary. These risk factors include systemic diseases
, disruption of cerebral venous flow, certain endocrine
or metabolic disorders, and exposure to or withdrawal
from certain exogenous substances.

8. Exogenous substances
• amiodarone,
• antibiotics (eg, nalidixic acid, penicillin, tetracycline),
• carbidopa, levodopa,
• corticosteroids (eg, topical, systemic),
• cyclosporine,
• danazol, growth hormone,
• indomethacin, ketoprofen,
• lead,
• leuprolide acetate, levonorgestrel implants,
• lithium,
• oral contraceptives, oxytocin,
• phenytoin,
• vitamin A (>100,000 U/d)/retinoic acid
• withdrawal from corticosteroids

9. Systemic diseases
• A myriad of illnesses are associated with idiopathic intracranial hypertension.
Some of these disorders result in an increased viscosity of the cerebrospinal
fluid.
• anemia,
• chronic respiratory insufficiency,
• familial Mediterranean fever,
• hypertension,
• multiple sclerosis,
• polyangiitis overlap syndrome,
• psittacosis,
• renal disease,
• Reye syndrome,
• sarcoidosis,
• systemic lupus erythematosus,
• thrombocytopenic purpura.

10. Disorders of cerebral venous drainage
• Cerebral venous compression by extravascular tumors or
secondary thrombosis results in impaired absorption of the
cerebrospinal fluid and, thus, idiopathic intracranial hypertension.
Restriction of venous drainage from the head may be impaired
with radical neck dissection, even if completed only on the right
side (predominant drainage from the head is via the right jugular
vein). Spontaneous recanalization usually occurs, but, if delayed,
chronic papilledema may result.
• The diagnosis of cerebral sinus thrombosis may be
missed with the exclusive use of computed
tomography (CT). Therefore, either in patients who
present atypically or in management dilemmas, ruling
out cerebral venous thrombosis with the use of
magnetic resonance imaging (MRI)/venography is
worthwhile

11. – Endocrine disturbances: Pregnancy is occasionally
associated with idiopathic intracranial
hypertension. This disorder can present at any
stage of pregnancy. Given the limitations of
neuroimaging studies and of medically treating
patients who are pregnant, both the diagnosis and
the management of these patients are
determined on a case-by-case basis. Any
neuroimaging studies or therapeutics should be
performed in conjunction with the patient's
obstetrician.

12. CLINICAL
History
• Patients usually present with symptoms related to increased intracranial pressure.
These symptoms include headache, transient visual obscurations, and diplopia due
to unilateral or bilateral sixth nerve palsy. Rarely, patients presenting with
increased intracranial pressure with related optic nerve edema may be
asymptomatic.
• Nonspecific symptoms may include dizziness, nausea, vomiting, and tinnitus.
• Headaches
– Headaches are recorded in 99% of patients presenting to neurologists and slightly less in
patients presenting to ophthalmologists.
– The pain is generally described as being diffuse, which worsens in the morning and is
exacerbated by the Valsalva maneuver.
• Transient visual obscurations: This visual symptom occurs in most patients. The
disturbance usually lasts 1-5 seconds and is described as a graying out of vision.
Orthostatic changes, such as standing up or bending over, induce this symptom.
• Diplopia: Patients who present with double vision most frequently complain of
horizontal displacement of the images. Vertical diplopia is rare, but it has been
reported.

13. Physical examination
• bilateral disc edema
• This papilledema varies from patient to patient and is indistinguishable from optic nerve swelling
caused by intracranial space-occupying lesions. In more pronounced cases of disc swelling, macular
involvement with subsequent edema and diminished central vision may be present.
• High-grade and atrophic papilledema in addition to subretinal hemorrhages are poor visual
prognostic signs.
• In some instances, the disc swelling is asymmetric, or, rarely, the appearance of the optic nerve may
be relatively normal.
• If left untreated, chronic disc swelling eventually leads to clinically significant visual loss. Although
all patients present with enlarged blind spots during their initial perimetry, uncontrolled
papilledema results in progressive peripheral visual field constriction or nerve fiber bundle defects
(eg, nasal depression, nasal steps, arcuate scotomas).
• The central visual field is affected in end-stage chronic papilledema.
• Sudden loss of central vision may result from an associated anterior ischemic optic neuropathy, a
vascular occlusion, or an associated subretinal neovascular membrane.
• The diplopia noted in patients with idiopathic intracranial hypertension is invariably due to
unilateral or bilateral sixth nerve palsy. These cranial nerve palsies diminish with the lowering of the
intracranial pressure.
• Occasionally, patients with diplopia present with oculomotor or trochlear nerve palsy.
• In rare instances, vertical diplopia is due to a skew deviation

14. • papilledema

15. FUNDOSCOPIC EXAM
Normal Papilledema

16. DIFFERENTIALSPapilledema
• intracranial tumour
• dural sinus thrombosis
• Pseudopapilledema
• Drusen of the optic nerve heads
• Malignant hypertension
• Bilateral infiltrative/infectious/inflammatory optic
neuropathy
• Bilateral anterior ischemic optic neuropathy
• Bilateral optic nerve papillitis
• Bilateral optic nerve tumors ,eg, glioma, meningioma

18. Diagnosis
The original criteria for IIH were described by Dandy
in 1937.
• Dandy criteria
1. Signs & symptoms of increased ICP – CSF
pressure >25 cmH2O
2 .No localizing signs with the exception of
abducens nerve palsy
3 .Normal CSF composition
4 .Normal to small (slit) ventricles on imaging with
no intracranial mass

19. Modified Dandy criteria
1. Symptoms of raised intracranial pressure (headache,
nausea, vomiting, transient visual obscurations, or
papilledema)
2 .No localizing signs with the exception of abducens (sixth)
nerve palsy
3. The patient is awake and alert
4. Normal CT/MRI findings without evidence of thrombosis
5 .LP opening pressure of >25 cmH2O and normal biochemical
and cytological composition of CSF
6 .No other explanation for the raised intracranial pressure

20. Neuroimaging
– A patient with bilateral disc swelling should undergo
urgent neuroimaging studies to rule out an intracranial
mass or a dural sinus thrombosis.
– Although CT is certainly adequate in most instances, MRI
and magnetic resonance venography are effective in ruling
out both a mass lesion and a potential dural sinus
thrombosis.
• In the setting of idiopathic intracranial
hypertension, the findings on neuroimaging studies
either are normal or demonstrate small slitlike
ventricles, enlarged optic nerve sheaths, and
occasionally an empty sella

21. Ultrasonography
– Standardized A-scan orbital ultrasonography precisely
measures the diameter of the optic nerve sheath.
– If this diameter increases in primary gaze and
diminishes by 25% in eccentric gaze (30° test), then
increased subarachnoid fluid surrounding the optic
nerve is presumably present. This finding is consistent
with papilledema if it is bilateral.
• The drawback of this noninvasive technique is
that it requires a highly skilled clinician to obtain
reproducible results

22. Lumbar puncture
– Once an intracranial mass lesion is ruled out, a lumbar puncture is
indicated. The opening pressure should be measured with the patient
relaxed to avoid a falsely elevated pressure reading.
– The clinician performing the procedure must indicate to the
ophthalmologist if any specific difficulty was encountered that may
have falsely elevated the pressure reading.
– Unfortunately, some patients demonstrate a transiently normal
pressure despite their harboring idiopathic intracranial hypertension.
Confirming the disease in these patients is difficult.
• Besides the value of the opening pressure, the clarity and the color
of the cerebrospinal fluid should be noted. In addition, the
cerebrospinal fluid should be forwarded for assessment of the cell
count, cytology, culture, glucose, protein, and electrolyte
concentration. All of these findings are normal in patients with
idiopathic intracranial hypertension

23. The medical management
– Weight control for patients who are overweight
• Most patients with this disorder are females who are overweight.
Weight loss is a cornerstone in the management of these patients.
Unfortunately, weight reduction generally proves to be a difficult
task for these patients.
• As little as a 6% weight loss has been demonstrated to result in a
reduction of the intracranial pressure with the accompanying
resolution of papilledema.
• To formalize the process of weight reduction, referral
to a dietitian may be appropriate
– Treatment of related underlying diseases
– Cessation of exogenous agents related to increased
intracranial pressure

24. DRUGS
• Acetazolamide appears to be the most effective diuretic in
lowering the intracranial pressure.
• The initial dose should be 1 g/d. Although for compliance
purposes, the 500 mg sequel taken orally twice a day is
preferred;
• This dose can be increased to 2 g/d, although most patients
do not tolerate the troubling adverse effects (eg, extremity
paresthesias, fatigue, metallic taste when drinking
carbonated beverages, decreased libido) of this medication
at this high dose.
• In the event of intolerance to acetazolamide, furosemide may be used as a
replacement diuretic in this group. Unfortunately, furosemide does not appear
to be as effective as acetazolamide

25. • Drug Name
Acetazolamide (Diamox, Diamox Sequels)
• Description
Nonbacteriostatic sulfonamide; potent CA inhibitor, which is effective in diminishing fluid secretion. Lowers
intracranial pressure by decreasing production of cerebrospinal fluid. Inhibition of CA results in a drop in sodium
ion transport across the choroidal epithelium. Reduction of cerebrospinal fluid production occurs within hours.
• Adult Dose
500 mg sequels PO bid; up to 2,000 mg PO bid
Alternatively, 250 mg tab PO qid
• Pediatric Dose
5-10 mg/kg PO qid
• Contraindications
Documented hypersensitivity; hepatic disease; severe renal disease; adrenocortical insufficiency; severe
pulmonary obstruction
• Interactions
Can decrease therapeutic levels of lithium and alter excretion of drugs
(eg, amphetamines, quinidine, phenobarbital, salicylates) by alkalinizing urine
• Pregnancy
C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits
outweigh risk to fetus
• Precautions
Caution in severe pulmonary disease or in those patients taking high doses of aspirin; adverse reactions may
include drowsiness, paresthesias, anaphylaxis, Steven-Johnson syndrome, rash, crystalluria, renal calculus
(patients are advised to drink sufficient amounts of water during the day), bone marrow
depression, thrombocytopenic purpura, hemolytic anemia, leukopenia, pancytopenia, and agranulocytosis

26. DRUGS
• Drug Name
Furosemide (Lasix)
• Description
Unclear how it inhibits cerebrospinal fluid production. A combination of CA inhibition and effect on sodium
absorption across the choroid plexus may result in the decrease of cerebrospinal fluid production.
• Adult Dose
20-40 mg PO bid initially; may increase by 20 mg to maximum 80 mg PO bid with appropriate monitoring
• Pediatric Dose
Not established
• Contraindications
Documented hypersensitivity; hepatic coma; anuria; severe electrolyte depletion
• Interactions
Metformin decreases furosemide concentrations; furosemide interferes with hypoglycemic effect of antidiabetic
agents and antagonizes muscle relaxing effect of tubocurarine; auditory toxicity appears to be increased with
coadministration of aminoglycosides and furosemide; hearing loss of varying degrees may occur; anticoagulant
activity of warfarin may be enhanced when taken concurrently with this medication; increased plasma lithium
levels and toxicity are possible when taken concurrently with this medication
• Pregnancy
C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits
outweigh risk to fetus
• Precautions
Perform frequent serum electrolyte, carbon dioxide, glucose, creatinine, uric acid, calcium, and BUN
determinations during first few months of therapy and periodically thereafter

27. – Corticosteroids
• Corticosteroids are effective in lowering the intracranial
pressure in those patients with an inflammatory
etiology for their idiopathic intracranial hypertension.
• In addition, steroids may be used as a supplement to
acetazolamide to hasten recovery in patients who
present with severe papilledema.

28. Surgical Care
• Optic nerve sheath fenestration
– Optic nerve sheath fenestration has been demonstrated to result in the
reversal of optic nerve edema with some recovery of optic nerve function. The
approach to the optic nerve may be from the medial or lateral aspect of the
orbit; each technique has its benefits and drawbacks.
– Occasionally, a bilateral curative effect of the papilledema occurs from
unilateral surgery. However, if this is not the case, then the opposite nerve
must undergo the same procedure.
– Although the intracranial pressure remains elevated in these patients
postoperatively, the local filtering effect of the fenestration acts as a safety
valve and eliminates the pressure from being transmitted to the optic nerve.
– Complications related to this procedure include diplopia, optic nerve
injury, vascular occlusion, a tonic pupil, and the inherent risk of hemorrhage
and infection with intraconal surgery.
• Unfortunately, Spoor has demonstrated that the long-term success rate of
this operation may be only 16%.

29. Optic nerve sheath fenestration
• Via lateral orbitotomy app
•Window of dura and
arachnoid made
•Arachnoid excised
•CSF allowed to drain

30. Cerebrospinal fluid diversion
procedures
• lumboperitoneal shunt,
• ventriculoperitoneal shunt
– who do not respond to maximum medical
treatment.
– patients with intractable headaches, where no
access is available to a surgeon who is comfortable
with optic nerve sheath fenestration
– patients with a failed optic nerve sheath
fenestration.

31. LP,VP SHUNTS
• The initial procedure is usually a lumboperitoneal (LP) shunt, which
connects the subarachnoid space in the lumbar spine with the
peritoneal cavity. Generally, a pressure valve is included in the
circuit to avoid excessive drainage when the patient is erect and
therefore has a relatively high ICP. LP shunting provides long-term
relief in about half the cases; others require revision of 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, respectively.
Given the reduced need for revisions in ventricular shunts, it is
possible that this procedure will become the first-line type of shunt
treatment.

32. • Poor Prognostication Factors
– Older age
– Raised IOP
– Systemic hypertension
– DM
– Weight gain during first year prior to diagnosis
– Anaemia
– High myope