Idiopathic Intracranial Hypertension
This site does not accept referrals or provide clinical advice in response to questions. If you are a New Zealand health professional seeking clinical advice, please use your local clinical pathway. If you are a New Zealand child patient, parent or caregiver seeking clinical advice, please contact your usual doctor. You can read the full site disclaimer here.
Within This Document
Idiopathic intracranial hypertension (IIH), formally known as pseudo tumour cerebri and benign intracranial hypertension, is a disorder of raised intracranial pressure of unknown cause. It commonly presents with headache and clinical findings of papilloedema and elevated cerebrospinal fluid opening pressure (CSF-OP).
This guideline is intended to assist in the appropriate diagnosis and management of children and adolescents with IIH and to help clinicians distinguish those children with secondary causes of intracranial hypertension or other causes of headache, such as migraine.
Idiopathic intracranial hypertension is rare with an incidence of 0.5-1.5/100 000 in the paediatric population. Obese pubertal teenage girls have the greatest risk, however younger patients and those with a normal BMI can also be affected.
The history in any child with suspected IIH should include:
|Headache (91%)||o Daily, diffuse, non-pulsatile
o Severe in the morning
o Exacerbated by lying flat, valsalva and cough
Note: Headache is often less prominent in prepubertal children and may be of any type
|Visual symptoms||o Diplopia, blurred vision
o Transient visual obscurations, particularly if precipitated by change in position
o Retro-orbital pain and pain with eye movement
o Reduced visual acuity and visual field loss are late signs requiring URGENT intervention
|Learning/cognitive difficulties, irritability|
|Recent rapid weight gain|
|Check for symptoms of obstructive sleep apnoea|
o Rhinorrhea, otorrhea
|Height, weight, BMI|
|Detailed neurological examination including||o Visual acuity
o Eye movements for a unilateral or bilateral lateral rectus (CN VI) palsy
o Visual fields
o Direct fundoscopy
A formal ophthalmology review is recommended in all patients suspected of having IIH.
Ophthalmology review should include assessment of visual acuity, formal visual field testing, colour vision, fundoscopic examination and optic disc photos when possible. Visual field defects are present in up to 90% of children at presentation, while up to 30% will have reduced visual acuity.
Papilloedema is difficult to diagnose with 100% certainty using direct fundoscopy alone as optic nerve drusen, optic neuritis and other pathology can have a very similar appearance.
B-scan ultrasonography can be used to detect drusen (although with less sensitivity in the paediatric population) and measure the diameter of the optic nerve sheath. Optical coherence tomography (OCT) and fundus autofluoresence can also detect drusen. These additional modalities should be considered in a child with bilateral papilloedema and few other features to support a diagnosis of IIH.
Imaging is required prior to undertaking a lumbar puncture to rule out other causes of increased intracranial pressure and support the diagnosis of IIH.
MRI with MRV is the preferred modality, as cerebral venous sinus thrombosis can present in a similar manner.
MRI findings seen in IIH include:
- Optic nerve abnormalities:
Tortuosity of the optic nerves
Enhancement of optic nerve head
Dilation of optic nerve sheath
- Flattening of the posterior globe
- Venous sinus stenosis. NB once pressure is lowered, venous sinuses may normalise on repeat MRI.
- Partially empty sella turcica
- Enlarged arachnoid outpouchings
Lumbar puncture with opening pressure
Involve Play Specialist to prepare patient where possible. Consider analgesia and sedation requirements well ahead of time.
Location should be low stimulus. Ensure access to a digital disposable manometer where possible
Suggested process of care is:
1. Ametop - 45 min prior - clinician to select likely puncture location ahead of time
2. Infiltrate with generous amount of lignocaine, at least to depth of spinous process. Infiltration of lignocaine can be painful - see Starship guideline on local anaesthesia for minor procedures for a range of techniques to reduce this pain
3. If lignocaine infiltration is not tolerated, then the use of Entonox during infiltration is suggested
- Lumbar puncture
The child should be in the lateral decubitus position with legs extended if possible. If Entonox has been required for lignocaine infiltration then wait 15 min before performing LP.
Sedation, including nitrous oxide, general anaesthesia and ketamine may increase opening pressure. Crying and hyperventilation will also increase opening pressure.
Preferred sedation options include clonidine and midazolam.
Reference values (90th centile CSF opening pressure)
Opening Pressure Obese child ≥ 28cm H2O Sedated child ≥ 28cm H2O Non-obese, non-sedated child ≥ 25cm H2O
A single lumbar puncture with opening pressure should be interpreted with caution as CSF opening pressure values vary minute to minute. There is some evidence that a sub-group of children with opening pressures of 20-28cm H2O AND other clinical features strongly supportive of idiopathic intracranial hypertension (papilloedema, classic headaches, visual symptoms, VIth nerve palsy and/or MRI features) also benefit from treatment. A repeat lumbar puncture, intracranial pressure monitoring, or trial of medication should be considered in these children.
If the opening pressure is elevated CSF should be removed until it reaches 20-25cm H2O. CSF should be routinely sent for cell count, protein and microscopy +/- cytology.
Causes of secondary intracranial hypertension
- Traumatic brain injury
- Hydrocephalus, obstructive or communicating
- Intracranial mass or bleed
- CNS infection
- Cerebral venous sinus thrombosis
- Chiari malformation.
Other causes of intracranial hypertension or conditions associated with IIH include:
- Malignant systemic hypertension
- Obstructive sleep apnoea
- Post malnutrition syndrome
- Adrenal insufficiency
- Pregnancy/ Eclampsia
- Polycystic ovarian syndrome
- Vitamin D deficiency
- Iron deficiency
Medications associated with raised intracranial pressure:
- Doxycycline/ Tetracycline/ Minocycline
- Growth hormone
- Corticosteroids ( withdrawal )
- Cyclosporine A
- Oral contraceptives
- Retinoic acid
- Vitamin A ( excess or deficiency)
Recommended blood tests (to exclude secondary causes)
- Urea, electrolytes, creatinine, parathyroid hormone, calcium, magnesium, phosphate
- Full blood count
- Coagulation screen
- Thyroid function
- Coeliac antibodies
- Lupus anticoagulant, anticardiolipin antibodies, ENA screen thrombophilia screen
- Iron studies
- Consider (if at risk of exposure or deficiency):
- Blood lead level
- Vitamin A
- Vitamin B12, folate
- Weight loss with referral to a dietician is recommended in all obese patients. Loss of 6% of body mass is associated with resolution of papilloedema
- Vitamin D and iron supplementation should be considered
- Treat obstructive sleep apnoea if present as per local guideline
- Treat hypertension if present
Dose Side effects Other Acetazolamide 25mg/kg/day up to a maximum of 100mg/kg/day
Can be divided TDS
(Max: 1-2g daily)
Anorexia, malaise, metallic taste, GI upset, fatigue, parasthesia, dyspnoea, metabolic acidosis Associated with most improvement in visual field loss and CSF pressure.
May aid weight loss.
Topiramate Commence 25mg nocte increase up to 100-150mg Anorexia, fatigue, parasethesias, renal stones, metabolic acidosis Can be used for migraine prophylaxis.
May aid weight loss.
Metabolic alkalosis, electrolyte imbalance, hyperglycemia, hypotension Synergistic effect when given with acetazolamide
Corticosteroids: Intravenous or oral corticosteroids can be used in cases of fulminant idiopathic intracranial hypertension. Discussion with the on-call neurologist is advised.
- Serial lumbar puncture. CSF reforms within 6 hours, unless there is a leak, therefore lumbar puncture with removal of CSF is only useful as a temporising measure.
Indications for referral:
- Fulminant onset disease (symptoms over <4 weeks with visual loss at presentation)
- Progressive visual loss despite maximal medical therapy
- Medication non-compliance and progressive visual loss
- Anticipated hypotension, e.g. renal dialysis, that could precipitate optic neuropathy
Surgical options include:
- Lumboperitoneal shunt
- Ventriculoperitoneal shunt
- Transverse sinus stenting
- Optic nerve sheath fenestration
- Bariatric surgery
- Ophthalmological and
neurological follow up is guided by the severity of the IIH at
- Initial ophthalmological follow-up should occur at 2 weeks
- Follow up should then stretch to 6 weekly then 3 monthly and 6 monthly depending on eye findings
- Children with visual loss at onset will requiring weekly follow-up initially
- Children on acetazolamide and other pressure lowering treatments requiring regular assessment for low pressure headaches and side effects (including renal calculi). Whilst on acetazolamide monitoring of FBC, U+E's, bicarbonate and LFTs to be completed at 2 weeks, then 3 months post commencement.
- Visual field loss will persist in ~17% of patients. 10% will have on-going loss of visual acuity.
- Avery et al. (2010). Reference range for cerebrospinal fluid opening pressure in children. N Engl J Med. 363: 891-893.
- Awlward A. & Reem R. (2017). Paediatric Intracranial Hypertension. Pediatric Neurology. 66: 32-45.
- Eds. (2017). How his is a "high" CSF opening pressure in paediatric pseudo tumour cerebri?. European Journal of Paediatric Neurology. 248-249.
- Gee A. & Wall M. (2017). Idiopathic intracranial hypertension (pseudotumour cerebri): Epidemiology and pathogenesis. Uptodate. Retrieved from: www.uptodate.com
- Gee A. & Wall M. (2017). Idiopathic intracranial hypertension (pseudotumour cerebri): Prognosis and treatment. Uptodate. Retrieved from: www.uptodate.com
- Gee A. & Wall M. (2017). Idiopathic intracranial hypertension (pseudotumour cerebri): Clinical features and diagnosis. Retrieved from: www.uptodate.com
- Krishnakumar et al. (2014). Idiopathic intracranial hypertension in childhood: pitfalls in diagnosis. Developmental medicine & child neurology. 56: 749-755.
- Skau et al. (2013). Diagnostic value of optical coherence tomography for intracranial pressure in idiopathic intracranial hypertension. J Headache Pain. 14: 166.
- Tibussek D., et al. (2016). Probable pseudotumour cerebri complex in 25 children. Further support of a concept. European Journal of Paediatric Neurology. Article in press.
Document last reviewed: June 2018
More From Starship
Information about the Paediatric Society of New Zealand