Idiopathic intracranial hypertension
From IDWiki
aka. pseudotumor cerebri
Definition
- Increase in intracranial pressure without an identifiable cause
- Defined as elevated opening pressure > 25cm H2O on lumbar puncture without identifiable intracranial structural pathology
Pathophysiology
- Most likely from elevated venous pressure causing decreased CSF resorption
Differential Diagnosis
- Severe iron deficiency anemia
- Sickle cell anemia
- Leukemia
- Addison disease
- Pregnancy, PCOS
- Hypothyroidism, thyrotoxicosis
- Hypocalcemia
- Renal failure
- COPD
- Right heart failure with lumpnary hypertension
- OSA
- SLE, sarcoid
- CSVT/IJV thrombus
- Meningitis
- Otitits media, lyme, HIV, varicella, sinusitis, viral disease, febrile illness, Strep B pharyngitis
- Medication
Risk Factors
- Obese female of child-bearing age
- Hypervitaminosis A
- Tetracycline antibiotics
- Isotretinoin
- Oral contraceptive pills
- Phenytoin
- Pregnancy
- Glucocorticoid use or withdrawal
Clinical Presentation
- History
- Diffuse, steady or throbbing headache that is worse in the morning
- Visual obscurations: bilateral dimming of vision lasting seconds
- Blurred vision, scotomas, and diplopia
- Pulsatile tinnitus, dizziness, and neck pain
- Signs & Symptoms
- Papilledema
- Strabismus from CN VI palsy
Investigations
- Labs
- Imaging
- MRI brain may show small ventricles, partially empty sella turcica, widening of the optic nerve sleeves, optic nerve buckling, or flattening of the optic globes, or may be normal
- Other
- [Lumbar puncture] with opening pressure for diagnosis
- [Visual field testing] is crucial
Criteria
- modified dandy's criteria
- s/s of increased ICP
- no neuro signs except CN VI palsy
- normal CSF
- no hydrocephalus/mass/etc on MRI
- no other cause of incranranial hypertension
- opening pressure >25cm
- clear clinical response to LP drainage
Management
- Acute
- Discontinue offending medication, if any
- Chronic
- Acetazolamide
- Topiramate
- LP for decompression, including repeated
- Medication
- Acetazolamide
- Topiramate
- Corticosteroids
- Repeat LPs, often every 1-3 months despite medications
- Remove causative factors, including counselling on weight loss
- Refer to Ophthalmology and Neurology
- May need surgical intervention if sight is threatened or treatment with medication fails
References
- ^ D. I. Friedman, G. T. Liu, K. B. Digre. Revised diagnostic criteria for the pseudotumor cerebri syndrome in adults and children. Neurology. 2013;81(13):1159-1165. doi:10.1212/wnl.0b013e3182a55f17.
