2. • Idiopathic intracranial hypertension (IH),
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.
.
3. Symptoms
• Headache.
• Nausea and vomiting.
• 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
4. Pathophysiology
• The Monro-Kellie rule states that the
intracranial pressure is determined by the
amount of brain tissue, cerebrospinal fluid
(CS) and blood inside the bony vault.
5. • 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.
• Obstruction of the veins that drain blood
from the brain.
6. • First theory: Increased production of
cerebrospinal fluid, was proposed in early
descriptions of the disease.
• Second theory :Increased blood flow to the
brain or increase in the brain tissue itself may
result in the raised pressure.
7. • Third theory: Blood flow from the brain may
be impaired or congested.
8. 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: In children, there is no difference in
incidence between males and females
9. Causes
• Obase women
• Pregnency
• systemic diseases.
• Disruption of cerebral venous flow.
• Certain endocrine or metabolic disorders.
15. • Papilledema varies from patient to patient.
• 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.
• left untreated, chronic disc swelling eventually
leads to clinically significant visual loss.
17. • Dandy criteria Signs & symptoms of increased
ICP - CSF pressure >25 cmH2O.
• No localizing signs with the exception of
abducens nerve palsy Normal CSF
composition Normal to small (slit) ventricles
on imaging with no intracranial mass.
18. Modified Dandy criteria
• Symptoms of raised intracranial pressure
(headache, nausea, vomiting, transient visual
obscurations, or papilledema).
• No localizing signs with the exception of
abducens (sixth) nerve palsy.
• The patient is awake and alert Normal CT/MRI
findings without evidence of thrombosis LP
opening pressure of >25 cmHO and normal
biochemical and cytological composition of
CSF No other explanation for the raised
intracranial pressure.
19. 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
23. 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.
• some patients demonstrate a transiently normal
pressure despite their harboring idiopathic
intracranial hypertension.
• Besides the value of the opening pressure.
• Color of the cerebrospinal fluid should be noted.
24. • cerebrospinal fluid
• assessment of the cell count.
• Cytology.
• culture.
• glucose.
• protein.
25. Medical Management
• Weight control.
• DRUGS:
• Acetazolamide The initial dose should be 1g/d
can be incresed upto 2 g/d.
• Side effects : Extremity paresthesias, fatigue,
metallic taste when drinking carbonated
beverages, decreased libido
26. • Corticosteroids:
• Effective in lowering the intracranial pressure
in those patients with an inflammatory
etiology for their idiopathic intracranial
hypertension.
• Steroids may be used as a supplement to
acetazolamide to hasten recovery in patients
who present with severe papilledema.
27. Surgical Treatment
• Optic nerve sheath
fenestration
• Optic nerve sheath
fenestration area shown
"Window in optic nerve
sheatt Via lateral
orbitotomy app Window
of dura and arachnoid
made Arachnoid
excised CSF allowed to
drain.
28. • 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.
• 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.
29. Complications :
• Diplopia.
• Optic nerve injury.
• vascular occlusion.
• Atonic pupil
• Infection with intraconal surgery.
• long-term success rate of this operation may
be only 16%.
30. CSF diversion procedures
• 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.
