IDIOPATHIC INTRACRANIAL HYPERTENSION William L Hills, MD Neuro-ophthalmology Oregon Neurology Associates Affiliated Assistant Professor Ophthalmology and Neurology Casey Eye Institute, OHSU No disclosures CASE - 19 YO WOMAN WITH HEADACHES X 3 MONTHS Headaches frontal PMHx: obesity Worse lying down Meds: takes ibuprofen for headaches Wake from sleep Pulsatile tinnitus 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 visual field testing: Enlargement of the blind spot, generalized constriction both eyes. MRI brain: Lumbar puncture: Posterior flattening of Opening pressure 39 the globes cm H20 Empty sella Normal CSF studies otherwise normal Headache improved after LP IDIOPATHIC INTRACRANIAL HYPERTENSION SYNDROME: Increased intracranial pressure without ventriculomegaly 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 Friedman and Jacobsen. Neurology 2002; 59: Symptoms and signs reflect only those of - increased ICP or papilledema 1495 Documented increased ICP during LP in lateral decubitus position Normal CSF composition No evidence of mass, hydrocephalus, 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 Diplopia HEADACHE Almost all patients with IIH Daily, retro-bulbar Neck pain can be prominent features Throbbing, nausea, vomiting, photophobia Often worse supine HEMORRHAGES TRANSIENT VISUAL OBSCURATIONS Brief episodes of monocular or binocular vision loss Partial or complete Likely due to disc edema leading to ischemia of the optic nerve head VISUAL LOSS Blurred vision 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 Ataxia 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 Neuroimaging- 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 retina, 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 OPTIC DISC 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 veins- 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 arteries. 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 optic neuritis 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 thrombosis 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 globe at the insertion of the optic nerve- 80% patients Empty sella- 70% Distension of the perioptic nerve sheath- 45% Chiari malformation- 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 Hassan et al. Teaching NeuroImages: Idiopathic intracranial hypertension. Neurology. v 74 (7) Feb 2010, p e 24 HYPERTENSION IDIOPATHIC INTRACRANIAL INTRACRANIAL IDIOPATHIC 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, meningitis 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 monitoring 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. Hyperventilation can artificially lower opening pressure Valsalva can artificially raise opening pressure as high as 47 cm H20! Frequency and amplitude of elevation of cerebrospinal fluid 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 encephalopathy 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 71 121: Acan: Neurol Acta hypertension. Idiopathic al. et intracranial Dhungana Fluoroquinolones OCPs Danaxol Progesterone Lithium 82 Vitamin A, isotretinoin - 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 82 Acta Neurol Scan: 2010: 121: 71 hypertension. Idiopathic al. et intracranial Dhungana reported to be associated with IIH. SLE OSA Behcet’s disease