Idiopathic Intracranial Hypertension

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Ezra Charles
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1 Idiopathic Intracranial Hypertension Idiopathic intracranial hypertension (IIH) Pseudotumour cerebri (PTC) Benign intracranial hypertension (BIH) Increased intracranial pressure (ICP) without clinical, laboratory or radiological evidence of intracranial pathology Original criterias were formulated in 1937 by Walter Dandy Increased ICP with normal cerebrospinal fluid (CSF) findings and no sign of a brain tumour on ventriculography

radiological evidence of intracranial pathology Original criterias were formulated in 1937 by Walter Dandy

2 International Headache Society s s classification of IIH 1. Alert patient with neurological examination that either is normal or demonstrates any of the following abnormalities: (a) Papilloedema (b) Enlarged blind spot (c) Visual field defect (d) Sixth nerve palsy 2. Increased CSF pressure (>200 mm H2O in the non-obese,>250 mm H2O in the obese) 3. Normal CSF chemistry (low CSF protein is acceptable) and cellularity. 4. Intracranial disease (including venous sinus thrombosis) ruled out. 5. No metabolic, toxic or hormonal cause of intracranial hypertension. A presenting headache is attributed to idiopathic intracranial hypertension when the headache develops in close temporal relation to the increased intracranial pressure and improves after withdrawal of CSF. The headache should be progressive with at least one of the following: (a) Daily occurrence (b) Diffuse and/or constant non-pulsating pain (c) Aggravated by coughing or straining

palsy 2. Increased CSF pressure (>200 mm H2O in the non-obese,>250 mm H2O in the obese) 3. Normal CSF chemistry (low CSF protein is acceptable) and cellularity. 4.

3 Epidemiology Incidence 1-2 / / year All ages More frequent in obese women in childbearing age, incidence up to 21 / 100 / year Approximately 70% of the females are obese, (BMI > 26) Female:male ratio: 4.3:1 to 15:1 Association with obesity has not been proven in men and prepubertal children In prepubertal children no female predominance exists

4 Parenchymal oedema Slit-like / normal sized ventricles Possible increased water content and difussion in subcortical white matter Increased cerebral blood volume (CBV) Increased CBV in anaesthetized patients / no differences in regional CBV IIH/controls Excessive CSF production Animal studies, no support human studies - normal CSF flow in the cerebral aqueduct Compromised CSF resorption? Pathogenesis unknown Venous outflow obstruction Association with venous sinus hypertension Unrecognized sinus thrombosis, extraluminal compression, AVM with venous hypertension Venous sinus hypertension > insufficiently high driving pressure gradient from the subarachnoidal space to the venous system > increase in resistance of CSF absorption > raised ICP

5 Examination Neuroimaging Brain imaging should be normal To exclude secondary causes of IIH CT CT venography MRI Emptysella Flattening of the posterior sclera Dilation or tortuosity of the optic nerve sheet Gadolinium enhancement of the optic disc MR venography

Flattening of the posterior sclera Dilation or tortuosity of the

6 Symptomatic Focusing on lowering the CSF pressure Preventing visual defect development and disabling headaches Weight loss Best treatment Often difficult Treatment Acetazolamide (Diamox ) Reduces the CSF production Initial dose of 250 mg twice a day gradually increasing to mg Side-effects dosedependent acroparaesthesias, nausea, anorexia, hypokaliaemia, nephrolithiasis Furosemide ( mg/day) combined with potassium Mechanism is unclear Less potent than acetazolamide

twice a day gradually increasing to 1000 1250 mg Side-effects dosedependent acroparaesthesias, nausea, anorexia,

7 Treatment Repeated lumbar punctures Pressurereducing effect is short CSF shunting Lumboperitoneal (LP) shunt Ventriculoperitoneal (VP) shunt CSF shunting effective Dysfunctions and infections Optic nerve sheet decompression Local reduction of the pressure around the nerve Intracranial hypertension persists Postoperative complication rate is high, up to 50% Up to 32% experience deterioration in visual function after an initial successful fenestration

decompression Local reduction of the pressure around the nerve Intracranial hypertension persists Postoperative

8 Spontaneous Intracranial Hypotension (SIH) Kvinna -58 Tid väs frisk Ett par veckor innan jul tilltagande huvudvärk, positionell Så småningom helt sängliggande, släpper då nästan helt Huvudvärk och kräkningar när hon är uppe Volleyboll smashad mot ansiktet ca 4 v innan VC Migrän Söker akut LP 7 cm H2O, 16 mono, 0 poly, 20 ery. MR fynd förenliga med SIH Försämras, 2 v senare ny LP 16 cm H2O, 10 mon, 1 poly, 0 ery Blood patch utan effekt Senare personlighetsförändring, förvirrad, glömsk, synhallucinationer, huvudvärk SDH Op Bättre sedan ånyo sämre - även balans påverkad Reop

9 Spontaneous Intracranial Hypotension (SIH) Bättre, men fluktuerande och periodvis handikappande besvär Isotopcisternografi läckage från näsan? Fluorescin intrathecalt ÖNH op MR med intrathecal gaduliniumkontrast Blood patch, 30 ml Ryggbesvär Cervikalgi 6 mån senare - behöver lägga sig 15 min någon gång ibland Kontroll MR

Fluorescin intrathecalt ÖNH op MR med intrathecal gaduliniumkontrast Blood

10 Epidemiology Incidence 2-5/ /year in our region/year years of age Women:male, 2:1

11 Etiology / Pathogenesis Spontaneous spinal CSF leak Precise cause unknown Structutal weaknesss of the spinal meninges? Trauma - mechanical factors Dural defects Dural holes Fragile meningeal diverticula Abscence of the dura Mainly cervico-thoracic location

Trauma - mechanical factors Dural defects Dural holes Fragile

12 Spontaneous Intracranial Hypotension (SIH) ICHD-II diagnostic criteria for spontaneous intracranial hypotension headache Diffuse and/or dull headache that worsens within 15 min after sitting or standing and with 1 or more of the following: Neck stiffness Tinnitus Hypoacusis Photophobia Nausea At least 1 of the following: Evidence of low CSF pressure on MRI (eg, pachymeningeal enhancement) Evidence of CSF leakage on conventional myelography, CT myelography, or cisternography CSF opening pressure < 60 mm water in sitting position No history of dural puncture or other cause of CSF fistula Headache resolves within 72 h after epidural blood patching

Evidence of low CSF pressure on MRI (eg, pachymeningeal enhancement) Evidence of CSF leakage on conventional myelography, CT myelography, or cisternography CSF

13 Investigation Imaging CT MRI Radionuclide myelography CT myelography MRI myelography Fluorescininjection Lumbar puncture Pressure CSF analyzes, o Primarily lymphocytic pleocytosis Up to 200 cells/mm3 o Elevated protein content Up to 1000 mg/dl o Xanthochromia Probably due to increased permeability of dilated meningeal blood vessels and a decrease of CSF flow in the lumbar subarachnoid space.

to 200 cells/mm3 o Elevated protein content Up to 1000 mg/dl o Xanthochromia Probably due to

14 Diagnostic criteria for spontaneous spinal CSF leak and intracranial hypotension Am J Neuroradiol 29: May 2008 Criterion A, demonstration of a spinal CSF leak (ie, presence of extrathecal CSF), or, if criterion A not met: Criterion B, cranial MR imaging changes of intracranial hypotension (ie, presence of subdural fluid collections, enhancement of the pachymeninges, or sagging of the brain), and the presence of at least one of the following: 1) low opening pressure (60 mm H2O); 2) spinal meningeal diverticulum; 3) improvement of symptoms after epidural blood patching; or, if criteria A and B not met: Criterion C, the presence of all of the following or at least 2 of the following if typical orthostatic headaches are present: 1) low opening pressure (<60 mm H2O), 2) spinal meningeal diverticulum, and 3) improvement of symptoms after epidural blood patching. Patients with onset of symptoms after dural puncture or other penetrating spinal trauma are excluded.

brain), and the presence of at least one of the following: 1) low opening pressure (60 mm H2O); 2) spinal meningeal diverticulum; 3) improvement of symptoms after epidural blood patching; or, if

15 Gadolinium-Enhanced MR Cisternography to Evaluate Dural Leaks in Intracranial Hypotension Syndrome Am J Neuroradiol 29: Jan 2008 Lumbar puncture with injection of 0.5 ml gadopentetate dimeglumine into the lumbar subarachnoid space MR images of the cervical, thoracic, and lumbar regions in axial, coronal, and sagittal planes with fat-saturated T1-weighted images CSF leakage in 17 (89%) of 19 patients In 14 of the patients, the site of the dural tear was demonstrated In 3, the contrast leakage was diffuse No complications during the first 24 hours or the 6- to 12-month follow-up

5 ml gadopentetate dimeglumine into the lumbar subarachnoid space MR images of the cervical, thoracic, and lumbar regions in axial, coronal, and

16 Treatment Some resolves spontanously Bed rest, somewhat less successful in SIH Hydration Adding caffeine, scientific proof of its efficacy is lacking Epidural blood patch Typically, 10 to 30 ml. The patient should remain lying flat A larger volume of blood, up to 100 ml, could be used The EBP can be repeated in 5 days if the SIH headache recurs or if headache relief is incomplete In some patients, additional trials of EBP may be needed % good outcome when repeated up to three times Surgery

The patient should remain lying flat A larger volume of blood, up to 100 ml, could be used The EBP can be repeated in 5 days

Idiopathic Intracranial Hypertension Investigation and Treatment

Idiopathic Intracranial Hypertension Investigation and Treatment Dr CP White Consultant Paediatric Neurologist Abertawe Bro Morgannwg UHB January 2011 Definition a condition of increased intracranial pressure