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Home , Encephalopathy, Hydrocephalus, Intracranial pressure, Papilledema, Photophobia

IDIOPATHIC INTRACRANIAL

William L Hills, MD Neuro- Oregon Associates Affiliated Assistant Professor Ophthalmology and Neurology Casey Eye Institute, OHSU No disclosures CASE - 19 YO WOMAN WITH X 3 MONTHS

 Headaches frontal  PMHx:  Worse lying down  Meds: takes ibuprofen for headaches  Wake from

 Pulsatile x 1 month.  Vision blacks out transiently when she bends over or sits down

EXAMINATION

 Vision: 20/20 R eye, 20/25 L eye.  Neuro: PERRL, no APD, EOMI, VF full to confrontation.  Dilated fundoscopic exam: 360 degree blurring of disc margins in both eyes, absent SVP.  Formal testing: Enlargement of the blind spot, generalized constriction both eyes. 

MRI : :

 Posterior flattening of  Opening pressure 39 the globes cm H20  Empty sella  Normal CSF studies  otherwise normal  improved after LP IDIOPATHIC INTRACRANIAL HYPERTENSION :

 Increased without or mass lesion  Normal CSF composition

NOMENCLATURE

 Idiopathic intracranial hypertension (IIH)  Benign intracranial hypertension  Pseudotumor cerebri  Intracranial hypertension secondary to…

DIAGNOSTIC CRITERIA  Original criteria have been updated to reflect new imaging modalities: 1492 - 59: 2002; NeurologyJacobsen. and Friedman  Symptoms and signs reflect only those of increased ICP or 1495  Documented increased ICP during LP in lateral decubitus position  Normal CSF composition  No evidence of mass, , structural or vascular lesion on MRI or CT with contrast in typical patients and on MRI with MRV for all others.  No other cause of elevated ICP identified

MORBIDITY

 Papilledema associated vision loss  IIH 96% with visual field defect  60% improved  30% stable  10% worsened

EPIDEMIOLOGY

 Annual incidence  General population 0.9/100,000  Women 15 to 44 3.5/100,000  Women 20-44 and 20% above ideal body weight 19.3/100,000

EPIDEMIOLOGY

 Before puberty boys = girls  After puberty women affected 9 times as often as men  Rarely develops in patients over 45

CLINICAL MANIFESTATIONS

 Headache  Transient visual obscurations  Visual loss  Pulse synchronous tinnitus 

HEADACHE

 Almost all patients with IIH  Daily, retro-bulbar  Neck can be prominent features  Throbbing, , ,  Often worse supine HEMORRHAGES TRANSIENT VISUAL OBSCURATIONS

 Brief episodes of monocular or loss  Partial or complete  Likely due to disc leading to of the head

VISUAL LOSS

 Metamorphopsia  Temporal dark spot  Tunnel vision  Profound or complete blindness  Tempo variable: as soon as days PULSE SYNCHRONOUS TINNITUS

 Pulsatile tinnitus 60%  Unilateral or bilateral  Typically worse when lying down  Abolished with LP or jugular venous compression  Transmission of intensified vascular pulsations via CSF

DIPLOPIA

 Unilateral or bilateral 6th nerve palsy  Secondary to increased ICP  Binocular horizontal diplopia  Resolves when ICP lowered

BCSC Neuro-Ophthalmology 1999 OTHER SYMPTOMS:

 Paresthesias  Neck stiffness  Arthralgia shoulders, wrists, knees   Facial palsy- rare  Radicular pain  Depression

EVALUATION FOR SUSPECTED IIH

 History and neurologic exam  Dilated fundoscopic exam  Evaluation of optic nerve function- color vision, visual acuity  - usually MRI (?MRV)  Lumbar puncture with opening pressure and CSF analysis  Referral to confirm papilledema and for formal visual field testing (perimetry)

PAPILLEDEMA: WHAT TO LOOK FOR

1. Disc Elevation Focus on the , then focus on the top of the disc (not the cup) 2. Blurring of the margins The lower pole blurs first, then the upper pole, then the nasal aspect. The temporal aspect of the disc is the last portion to blur. 3. Vessel obscuration As the nerve fiber layer swells, the retinal vessels at the edge of the disc get obscured. NORMAL BLURRED MARGINS PAPILLEDEMA CONTINUED

4. Can you see the cup? The cup is the last part of the disc to become elevated. 5. Look at the - can you see pulsations? Venous pulsations are lost with elevated ICP, so will not be present in true papilledema. Veins become dilated and tortuous. This is easier to see if you compare them with the .  6. Look for things that shouldn’t be there- -hemorrhages. Usually at the border of the disc. -dilated capillaries forming a “hairnet” on the disc. This occurs in chronic papilledema -exudates- may look like drusen but will go away when papilledema resolves.  Hair net cappillaries  Vessel contour  Obscuration of vessels  Loss of physiologic cup ENGORGED TORTUOUS VEINS EXUDATES

GRADING PAPILLEDEMA

 Grade 1- blurring of the nasal, inferior and superior borders, with sparing of the temporal margin.  Grade 2- 360 degree elevation of the disc margin.  Grade 3- elevation of the entire disc with partial obscuration of the vessels at the margin.  Grade 4- complete obliteration of the cup and disappearance of at least some of the vessels on the disc’s surface  Grade 5- disc appears dome shaped with all vessels obscured.

Digre and Corbett. Practical viewing of the optic disc. PSEUDOPAPILLEDEMA

 Several benign conditions can cause a false appearance of disc swelling.  Optic nerve head drusen PSEUDOPAPILLEDEMA

 Tilted optic discs  Myelinated NFL

OPTIC NERVE FUNCTION

 Visual acuity < 20/20 in 15% at initial visit  Contrast sensitivity is early indicator of dysfunction  Color vision is insensitive to loss; unlike in  RAPD – if there is an asymmetry RISK FACTORS FOR VISUAL LOSS

 Recent weight gain  Subretinal  High grade hemorrhage papilledema  Atrophic papilledema  Significant visual loss at presentation  Hypertension

PERIMETRY

 Most useful for evaluating visual fxn  Enlarged blind spot  Generalized constriction  Inferonasal loss PERIMETRY: GENERALIZED CONSTRICTION FACTORS NOT PREDICTIVE OF VISUAL LOSS

 Duration of symptoms  Transient visual obscurations  Diplopia  Pulsitile intracranial noises  Degree of headache  Opening pressure  Pregnancy

NEUROIMAGING

 Primary role is to rule out other causes of elevated ICP other than IIH  Rule out hydrocephalus, mass lesion, venous sinus  Need to image (at least a CT) before LP  Traditional recommendation is MRI or contrast- enhanced CT in typical patients and MRI with MRV in all others.  Some authors recommend MRI/MRV for all patients with suspected IIH TYPICAL MRI FINDINGS OF IIH

 Flattening of the posterior at the insertion of the optic nerve- 80% patients  Empty sella- 70%  Distension of the perioptic nerve sheath- 45%  - small, asymptomatic, not seen in most patients

 Remember, the primary reason for imaging in IIH is to EXCLUDE other diagnoses

Diagnostic criteria for idiopathic intracranial hypertension. Friedman and Jacobson. Neurology v 59 p. 1492-1495 IDIOPATHIC INTRACRANIAL HYPERTENSION Feb 2010, p e 24 Feb2010, p e Neurology.hypertension.intracranial v 74 (7) et Idiopathic al. TeachingHassan NeuroImages: VENOUS SINUS THROMBOSIS

 Dangerous diagnosis to miss  Treatment is anticoagulation  Lin et al. obtained MRI/MRV in 106 patients with suspected IIH (patients with bilateral papilledema without mass lesions, or hydrocephalus).  10/106 (9.4%) of paients were found to have cerebral venous sinus thrombosis  Four of these patients were “typical” IIH patients (young, obese, female) and previous guidelines would not have recommended MRV for them.  Therefore the authors recommend obtaining MRV in all patients with suspected IIH

Lin et al. Occurrence of Cerebral Venous Sinus Thrombosis in Patients with Presumed Idiopathic Intracranial Hypertension. Ophthalmology 2006; 113: 2281-2284 LUMBAR PUNCTURE

 Lateral decubitus position with legs relaxed  18- to 20- gauge spinal needle  Document elevated CSF pressure

 Opening pressure > 250mm H20

 201 – 249 mm H20 are nondiagnostic  Repeat LP may be necessary if initial OP nondiagnostic  Rarely need 24 hour transducer through lumbar drain to diagnose DIAGNOSTIC PERILS OF LUMBAR PUNCTURE

 Opening pressure is normally higher in the obese (cutoff 300 mm H20 not 250 mmH20)  Radiologists usually position patient prone for fluoroscopic guided LP. Prone measurements are unsatisfactory!  Legs need to be straightened and patient relaxed.  can artificially lower opening pressure  Valsalva can artificially raise opening pressure as high as 47 cm H20!

Frequency and amplitude of elevation of resting pressure by the Valsalva manuever. Neville and Egan. Can J Ophthalmol. 2005; 40: 775-7 WORKUP FOR CONTRIBUTING FACTORS/MIMICS

 Vital signs- r/o hypertensive  Medications  Medical history  Consider sleep study to eval for OSA  Labs  Hct- anemia  TSH, free T4- hypothyroidism  Vitamin D level  Parathyroid level- hypoparathyroidism  CMP  Specific tests for suspected conditions suggested by the history MEDICATIONS ASSOCIATED WITH IIH

 Tetracyclines

 Nalidixic acid hypertension. Acta Neurol Acan: 121: 71 - Dhunganaintracranialet al. Idiopathic  Fluoroquinolones  OCPs  Danaxol  Progesterone  Lithium

, 82  Sulfamethoxazole  Steroids or steroid withdrawal  Growth hormone CONDITIONS ASSOCIATED WITH IIH

 Obesity and recent weight gain are the only conditions shown to be associated with IIH in case-control studies. But many conditions are reported to be associated with IIH. 82 hypertension. 71 - 121: 2010: Scan: Neurol Acta Dhunganaintracranialet al. Idiopathic  SLE  OSA  Behcet’s  Iron deficiency anemia  Addison’s disease  Hypothyroidism, hypoparathyroidism  PCOS  Obstruction to venous drainage  -sp thrombosis, elevated R heart pressure RED FLAGS

 Atypical demographic  Global  Rapid development of symptoms  INO  Explosive onset  Vertical gaze d/o  CN palsies other than VI  AMS  Other focal signs  Abnormal CSF TREATMENT

 Medical  Diet and weight loss  Medications  Surgical  Optic nerve sheath decompression  CSF shunting DIET AND WEIGHT LOSS

 Retrospective studies of significant weight loss demonstrated  Resolution of papilledema  improvement in headaches and pulsatile tinnitus  Retrospective study demonstrating papilledema grade and visual fields improved more rapidly in those that lost at least 2.5 kg over 3 months MEDICATIONS TO DECREASE ICP

 Carbonic anhydrase inhibitors   Other  Furosemide  Thiazides  Spironolactone  triamterene  Corticosteroids ACETAZOLAMIDE

 Effective in 75% with IIH  Effective dose 1 g to 4 g daily divided  Start at 500 mg daily x 1 week, then 500 mg BID  Most patients cannot tolerate beyond 2 g/day  Side effects – patients SHOULD get these  Paresthesias  Unpleasant with carbonated beverages  Altered taste of food  Low serum bicarbonate level

ACETAZOLAMIDE

 Severe reactions  Allergic rash  Aplastic anemia  Renal stones  Contains sulfa moiety TOPIRAMATE

 Inhibits carbonic anhydrase  Causes weight loss  Also beneficial for  Recent study compared topiramate with acetazolamide:  Open label, 40 patients, randomized  Acetazolamide started at 500 mg/day and titrated up to1000-1500 mg/day  Topiramate started at 50 mg/day and titrated up to 100-150 mg/day  Endpoint was visual field grade  Result: topiramate and acetazolamide equally efficacious TOPIRAMATE: SIDE EFFECTS

 Distal paresthesias  Cognitive impairment (dope-amax)  Rare serious side effects: acute , angle closure , kidney stones CORTICOSTEROIDS

 Rapidly decrease ICP  Not suitable for chronic use  Used in emergencies while awaiting  Corticosteroid use and steroid withdrawal are both associated with IIH  May rebound when tapered HEADACHE  Persistent or recurrent headaches may indicate elevated ICP  However, many patients have persistent headache even after normalization of intracranial pressure.  These headaches may be different from their initial “high pressure” headache.  In one study, 68% patients with IIH that was well controlled (resolution of papilledema and visual field abnormalities) developed new headaches.  30% had tension type headache, 20% had without Headache diagnoses in patients with treated idiopathic intracranial hypertension. Friedman and Rausch. Neurology v58 (10). 2002. p 1551-1553 HEADACHE MANAGEMENT

 First determine whether headache is due to elevated ICP.  History and exam, fundoscopic exam, perimetry.  Recognize overuse headache.  Treatment similar to migraine management.  TCA  Depakote  CCB  B blockers  Topamax  NSAIDS

SURGICAL TREATMENT

 Indicated for visual loss or worsening of vision attributable to papilledema that fails to respond to medication or is advanced at presentation.  NOT indicated for headache management  Optic nerve sheath decompression  CSF shunting  Repeated LP???? OPTIC NERVE SHEATH DECOMPRESSION  Mechanism not well understood  Filtering procedure  Perineuronal scarring shifts pressure gradient posteriorly  Increases blood flow to the optic nerve OPTIC NERVE SHEATH DECOMPRESSION

 Retrospective study  Improvement in visual field in 36%  Stabilization in 32%  Deterioration in 32%  Probability of failure 3 to 5 year post op 35%  Complications  Failure  Ischemic  Transient blindness CSF SHUNTING

 In the past, lumboperitoneal shunting preferred over ventricular shunting due to small ventricular size in IIH.  Improved surgical methods (stereotactic localization) has led to increased VP shunting.  In practice, decision is up to the surgeon.  Both VP and LP shunts are highly effective in the short term but have very high long-term failure and revision rates.  For example, retrospective series of 30 patients receiving LP .  All patients experienced relief of symptoms.  30 patients required 126 revisions (average of 4.2 revisions per patient!)

Surgery for idiopathic intracranial hypertension. Brazis. J Neuro-ophthalmol. Vol 29, n, 4, 2009 COMPLICATIONS

 Common Complications  --Shunt obstruction  --Shunt  --Overdrainage of CSF  -- migration

 In-Hospital Mortality Rate of 0.9% for VP shunt and 0.3% for LP shunt

Uretsky. Surgical interventions for idiopathic intracranial hypertension. Current opinion in ophthalmology. 2009; 20: 451-455 ENDOVASCULAR STENTING  Still experimental  Patients with IIH commonly have narrowing of the transverse sinuses on MRV.  Debatable whether this is causative or not. May be secondary. DONNET ET AL.

 10 consecutive patients with refractory IIH underwent direct retrograde cerebral venography and manometry.  All had morphologic obstruction of the transverse sinuses.  All underwent stenting of the venous sinuses  All had resolution of papilledema and normalization of CSF pressure at 3 month followup.

Donnet et al. Endovascular treatment of idiopathic intracranial hypertension. Neurology 70, p. 641-647 MONITORING AND FOLLOW-UP OF IIH

 Obtain formal visual fields at time of starting therapy. This needs to be done in a timely manner.  If no visual field abnormalities on initial testing, no visual complaints and just mild grade one papilledema probably don’t need repeat visual fields unless symptoms worsen.  All other patients: repeat visual fields after three months on treatment.  Sooner if symptoms get worse.  After three months repeat fields if papilledema worsens or symptoms worsen. IF PATIENT DOESN’T RESPOND TO DIURETICS…

 Obtain MRV/CTV if you have not already done so  Look for secondary causes of IIH  Reconsider diagnosis  Consider sending for shunting or ONSF PREGNANCY

 IIH may develop or worsen during pregnancy.  Occurrence rate is similar to age matched controls  No increased risk of fetal loss  Diagnostic criteria same  Acetazolamide – use after 20 weeks gestation  Avoid thiazide diuretics and TCA  Corticosteroids indicated with vision loss  ONSD or LP shunt MEN

 Constitute about 10% patients with IIH  Less likely to report headache  More likely to report visual disturbances  Twice as likely as women to develop severe visual loss  Visual function should be followed more closely because less likely to experience and report other symptoms of elevated ICP

Bruce et al. Idiopathic intracranial hypertension in men. Neurology v72 p. 304-309 FULMINANT IIH

 Defined as acute onset of symptoms and signs of IIH (less than 4 weeks between onset of initial symptoms and severe visual loss) with rapid worsening of visual loss over a few days and normal MRI/MRV  All have severe loss of visual acuity and severe bilateral papilledema at presentation.  Usually have very elevated opening pressure (mean 54.1 but range 29-70 cm H20)  Need MRV to rule out CVST

 Urgent surgery is usually required. 229 - v68, p. Neurologyhypertension.intracranial Thambisettyet al. Fulmiant idiopathic  Visual outcome correlates directly with time from 232 presentation to surgery  Temporizing measures include IV corticosteroids, IV acetazolamide, lumbar drain  In one study of 16 patients, 8 patients remained legally blind, these had surgery between 3-37 days after presentation. 8 patients recovered vision, these had surgery between hours to 4 days after presentation.

IIH WITHOUT PAPILLEDEMA?

 Does it really exist?  IIHWOP is recognized in the International Headache Society criteria  Digre et al. reviewed records of all patients with diagnosis of IIH at a neuro-ophthalmology clinic from 1990-2003  353 patients  20 (5.7%) were without papilledema PATIENTS WITHOUT PAPILLEDEMA

 Had lower opening pressures (309 vs 373 mm H20)  Most (75%) had spontaneous venous pulsations  73% had normal visual fields (vs. 13% in patients with papilledema)  20% had nonphysiologic constriction of visual fields  None had enlarged blind spot (vs. 59% in patients with papilledema)  55% had auras (vs. 20%)  Had poorer response to diuretics (30% vs 55%)