History

Fact Explanation
Severe daily pulsatile headaches, may awaken the patient in the morning and usually last hours. Retro-ocular pain and nausea can accompany this headache. Increased intracranial pressure causes headache and nausea.[1][3]
Episodes of transient blurred vision that usually last less than 30 seconds. This occur due to transient ischemia of the optic nerve head related to increased tissue pressure.[1]
Pulsatile intracranial noises or pulse synchronous tinnitus The sound is thought to be due to transmission of intensified vascular pulsations by means of CSF under high pressure and turbulence through smooth walled venous stenoses related to transverse sinus collapse from high CSF pressure.[1]
Diplopia Due to cranial nerve palsies ex: sixth nerve, diplopia is seen.[1]
Visual loss Visual loss occurs only when papilledema is long-standing and severe or if there is a serous retinal detachment present and optic disc edema extends to the macula.[1][2]
Use of vitamin A, tetracyclines, nalidixic acid ,nitrofurotoin,steroids,danazol,lithium,oral contraceptives,tamoxifen These may be the causative factors for benign intracranial hypertension.[1]
References
  1. WALL MICHAEL. Idiopathic Intracranial Hypertension. Neurologic Clinics [online] 2010 August, 28(3):593-617 [viewed 19 September 2014] Available from: doi:10.1016/j.ncl.2010.03.003
  2. THURTELL MATTHEW J., WALL MICHAEL. Idiopathic Intracranial Hypertension (Pseudotumor Cerebri): Recognition, Treatment, and Ongoing Management. Curr Treat Options Neurol [online] December, 15(1):1-12 [viewed 22 September 2014] Available from: doi:10.1007/s11940-012-0207-4
  3. DEGNAN A. J., LEVY L. M.. Pseudotumor Cerebri: Brief Review of Clinical Syndrome and Imaging Findings. American Journal of Neuroradiology [online] December, 32(11):1986-1993 [viewed 22 September 2014] Available from: doi:10.3174/ajnr.A2404

Examination

Fact Explanation
Papilloedema Bilateral optic disc oedema is seen when optic nerve is compressed by the high CSF pressure when encased in an optic sheath.[1][2]
Sixth nerve paresis Due to increased intra cranial pressure 6th nerve palsy can occur as a false localizing sign.[1][2]
Bell's type palsies of CN VII rarely occur and are usually transient. long nerve track and the bends can cause this palsy when elevated ICP directly compress this nerve.[1]
Visual field defects and Reduced visual acuity Optic nerve compression can result in these signs.[1]
High blood pressure Malignant hypertension may also cause bilateral optic nerve edema and is easily ruled out by taking the blood pressure.[1]
GCS is normal. In benign intra -cranial hypertension consciousness and alertness is preserved.[1]
No other neurological localizing signs except 6th and 7th LMN palsy. Since there is a generalised elevation of ICP[1][2]
References
  1. DEGNAN A. J., LEVY L. M.. Pseudotumor Cerebri: Brief Review of Clinical Syndrome and Imaging Findings. American Journal of Neuroradiology [online] December, 32(11):1986-1993 [viewed 22 September 2014] Available from: doi:10.3174/ajnr.A2404
  2. DIGRE K. B.. Idiopathic intracranial hypertension. BMJ [online] December, 341(jul07 2):c2836-c2836 [viewed 23 September 2014] Available from: doi:10.1136/bmj.c2836

Differential Diagnoses

Fact Explanation
Primary or metastatic CNS tumors. History of previous cancers and neuroimaging can exclude CNS tumors.[1][2]
Haemorrhage (Intra cerebral,sub arachnoid,subdural,extradural,intraventricular) Sudden onset and neuroimaging can diagnose CNS haemorrhage.[1][2]
Venous sinus thrombosis MRV(magnetic resonance venography) can diagnose this condition.[1][2]
Meningoencephalitis,brain abscess History, CSF examination and neuroimaging can diagnose CNS infections. [1]
Hydrocephalus Neuro imaging can exclude this condition.[1]
Status epilepticus Consiousness is preserved and seizures are unlikely in benign intracranial hypertension.[1]
References
  1. THURTELL MATTHEW J., WALL MICHAEL. Idiopathic Intracranial Hypertension (Pseudotumor Cerebri): Recognition, Treatment, and Ongoing Management. Curr Treat Options Neurol [online] December, 15(1):1-12 [viewed 22 September 2014] Available from: doi:10.1007/s11940-012-0207-4
  2. KARAHALIOS D. G., REKATE H. L., KHAYATA M. H., APOSTOLIDES P. J.. Elevated intracranial venous pressure as a universal mechanism in pseudotumor cerebri of varying etiologies. Neurology [online] 1996 January, 46(1):198-202 [viewed 23 September 2014] Available from: doi:10.1212/WNL.46.1.198

Investigations - for Diagnosis

Fact Explanation
CSF opening pressure Normal limits are less than 200 mm water in non-obese subjects.Values between 200 and 250 may be considered borderline with values over 250 mm water definitely elevated.[1][2][4]
CSF(White blood cell and differential counts,red blood cell count,total protein,glucose) In benign intracranial hypertension CSF composition is normal where as in CNS infections there will be anomalies.[1][2][4]
MRI brain (contrast) and MRV (magnetic resonance venography) Patients should undergo urgent neuroimaging studies to rule out intracerebral masses, , hydrocephalus,meningeal inflammatory or infiltrative disease, and dural venous sinus thrombosis. In benign intracranial hypertension, the findings on neuroimaging studies consist of normal or small slit like ventricles, flattening of the posterior pole of the eyes, dilation and tortuosity of the optic nerve sheaths,empty sella turcica,stenosis of one or both transverse cerebral venous sinuses. [1][2][3]
Blood Tests(Complete blood count,Erythrocyte sedimentation rate,Serum iron and iron-binding capacity, Antinuclear antigen profile ) These are useful for ruling out collagen-vascular diseases (Systemic lupus erythematosus etc.) These have been reported as underlying conditions in some those who present with idiopathic intracranial hypertension.[1][2]
References
  1. THURTELL MATTHEW J., WALL MICHAEL. Idiopathic Intracranial Hypertension (Pseudotumor Cerebri): Recognition, Treatment, and Ongoing Management. Curr Treat Options Neurol [online] December, 15(1):1-12 [viewed 22 September 2014] Available from: doi:10.1007/s11940-012-0207-4
  2. DEGNAN A. J., LEVY L. M.. Pseudotumor Cerebri: Brief Review of Clinical Syndrome and Imaging Findings. American Journal of Neuroradiology [online] December, 32(11):1986-1993 [viewed 22 September 2014] Available from: doi:10.3174/ajnr.A2404
  3. BIOUSSE V., BRUCE B. B., NEWMAN N. J.. Update on the pathophysiology and management of idiopathic intracranial hypertension. Journal of Neurology, Neurosurgery & Psychiatry [online] December, 83(5):488-494 [viewed 23 September 2014] Available from: doi:10.1136/jnnp-2011-302029
  4. WALL M., CORBETT J. J., FRIEDMAN D. I., LIU G., DIGRE K.. Revised diagnostic criteria for the pseudotumor cerebri syndrome in adults and children. Neurology [online] December, 83(2):198-200 [viewed 23 September 2014] Available from: doi:10.1212/01.wnl.0000452039.32455.3e

Investigations - Followup

Fact Explanation
Perimetry Visual loss can be accurately assessed by perimetry.Therefore to see whether if there is any improvement or deterioration of the vision it's done.[1]
MRI brain To look for a secondary cause when symptoms are not relieved inspite of treatment.[1]
References
  1. DEGNAN A. J., LEVY L. M.. Pseudotumor Cerebri: Brief Review of Clinical Syndrome and Imaging Findings. American Journal of Neuroradiology [online] December, 32(11):1986-1993 [viewed 22 September 2014] Available from: doi:10.3174/ajnr.A2404

Management - General Measures

Fact Explanation
Low sodium weight reduction diet. The patients' intake should reduced to 400-1000 calories per day by fruits, rice, vegetables and occasionally 1-2 oz of meat. Fluids should be limited to 750-1250 ml/day and sodium to less than 100 mg/day .Only modest degrees of weight loss in the range of 5-10% total body weight are needed for reversal of symptoms and signs.[1][2][4]
Withdraw of the offending agent. If the patient is using a drug which has the potential to cause increased intracranial pressure these should be withdrawn.[1][2][3]
Management of headache Lumbar puncture, amitriptyline 10 - 25 mg at bedtime. Non steroidal anti-inflammatory agents are used as an adjunct but their use is limited to two days per week to prevent the development of rebound headaches. Topiramate may be useful both for its migraine prophylaxis, side effect of weight loss and for carbonic anhydrase inhibition.Uncommonly, a CSF shunting procedure is needed for persistent headache; but it can produce the “hindbrain herniation” headache in return.[1][2]
References
  1. WALL MICHAEL. Idiopathic Intracranial Hypertension. Neurologic Clinics [online] 2010 August, 28(3):593-617 [viewed 19 September 2014] Available from: doi:10.1016/j.ncl.2010.03.003
  2. THURTELL MATTHEW J., WALL MICHAEL. Idiopathic Intracranial Hypertension (Pseudotumor Cerebri): Recognition, Treatment, and Ongoing Management. Curr Treat Options Neurol [online] December, 15(1):1-12 [viewed 22 September 2014] Available from: doi:10.1007/s11940-012-0207-4
  3. DANDY WE. INTRACRANIAL PRESSURE WITHOUT BRAIN TUMOR: DIAGNOSIS AND TREATMENT Ann Surg [online] 1937 Oct, 106(4):492-513 [viewed 23 September 2014] Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1390605
  4. SINCLAIR A. J., BURDON M. A., NIGHTINGALE P. G., BALL A. K., GOOD P., MATTHEWS T. D., JACKS A., LAWDEN M., CLARKE C. E., STEWART P. M., WALKER E. A., TOMLINSON J. W., RAUZ S.. Low energy diet and intracranial pressure in women with idiopathic intracranial hypertension: prospective cohort study. BMJ [online] December, 341(jul07 2):c2701-c2701 [viewed 23 September 2014] Available from: doi:10.1136/bmj.c2701

Management - Specific Treatments

Fact Explanation
Lumbar Puncture Lumbar puncture has only a short-lived effect on CSF pressure.Transverse sinus collapse (smooth walled venous stenoses) can resolve immediately with lowering pressure. CSF circulatory dynamics may be restored with this procedure and may give temporary relief until the sinus recollapses, usually within weeks. It is not uncommon to observe a lasting clinical remission following a single lumbar puncture in some IIH patients,obviating the need for further medical or surgical treatment. [1][3][4]
Corticosteroids Patients treated with steroids often respond well, but usually there is a recurrence of papilloedema with rapid tapering of the dose. This may be accompanied by marked deterioration of visual function. A prolonged tapering may prevent return of symptoms and signs in some patients.It's mainly used for short-term treatment of patients with a fulminant presentation while awaiting surgical intervention.[1][2]
Acetazolamide When 99.5% of choroid plexus carbonic anhydrase is inhibited it result in reduced CSF production; also, it changes the taste of foods and sometimes causes anorexia aiding in weight loss. [1][4]
Furosemide Intracranial pressure is lowered by both diuresis and reducing sodium transport into the brain. We initiate furosemide at a dose of 20 mg p.o. b.i.d. and gradually increase the dose, if necessary, to a maximum of 40 mg p.o. t.i.d. Potassium supplementation is given as needed.[1]
Optic nerve sheath fenestration Optic nerve sheath fenestration consists of either creating a window or making a series of slits in the optic nerve sheath just behind the globe. This treatment is preferred for the patient with progressive visual loss with mild or easily controlled headaches, although over 50% of patients with the procedure gain adequate headache control (especially if the headache is frontal)[1][2][4]
CSF Shunting Procedures Lumbar subarachnoid-peritoneal shunts, ventriculoatrial, ventriculojugular or ventriculoperitoneal shunts is generally, indicated when failed medical therapy or intractable headache.[1][4]
Venous sinus stenting Patients with increased ICP develop the stenoses due to external compression of the venous sinus.Stenting of these stenoses might reduce cerebral venous pressure, leading to increased CSF absorption, reduced ICP, and improved symptoms and signs.[1] [2]
References
  1. WALL MICHAEL. Idiopathic Intracranial Hypertension. Neurologic Clinics [online] 2010 August, 28(3):593-617 [viewed 19 September 2014] Available from: doi:10.1016/j.ncl.2010.03.003
  2. THURTELL MATTHEW J., WALL MICHAEL. Idiopathic Intracranial Hypertension (Pseudotumor Cerebri): Recognition, Treatment, and Ongoing Management. Curr Treat Options Neurol [online] December, 15(1):1-12 [viewed 22 September 2014] Available from: doi:10.1007/s11940-012-0207-4
  3. BIOUSSE V., BRUCE B. B., NEWMAN N. J.. Update on the pathophysiology and management of idiopathic intracranial hypertension. Journal of Neurology, Neurosurgery & Psychiatry [online] December, 83(5):488-494 [viewed 23 September 2014] Available from: doi:10.1136/jnnp-2011-302029
  4. MOLLAN S. P., MARKEY K. A., BENZIMRA J. D., JACKS A., MATTHEWS T. D., BURDON M. A., SINCLAIR A. J.. A practical approach to, diagnosis, assessment and management of idiopathic intracranial hypertension. Practical Neurology [online] 2014 May [viewed 23 September 2014] Available from: doi:10.1136/practneurol-2014-000821