Benign intracranial hypertension is a clinical syndrome consisting of raised intracranial pressure without any gross structural abnormality.
Features include:
- Headache – often worst in the morning
- blurred vision
- dizziness
- horizontal diplopia
- papilloedema
so essentially it presents like there should be a mass in the brain, but none can be found.
Note that despite it being called ‘benign’ up to 30% of patients have permanent significant vision loss - so its name of 'benign' is a little misleading! Optic nerve sheath fenestration can help prevent this.
Benign intracranial hypertension classically affects overweight young females.
Benign intracranial hypertension is also associated with:
- drugs
- antibiotics – tetracyclines, penicillin
- steroids
- danazol
- vitamin A
- lithium
- COC
- Pheytoin
- Obesity
- Systemic illness
- Anaemia
- hypertension
- MS
- SLE
- Renal disease
- Metabolic disturbance
- Thyroid disease
- diabetes
Management is:
- weight loss
- acetazolamide
- loop diuretics (some controversy)
- prednisolone
- therapeutic lumbar puncture
- shunt
Small print gem: normal CSF opening pressure is widely accepted as 10 to 20cm. However, some studies suggest levels up to 25cm should be seen as normal. It is also noted that in the general population BMI has a small but clinically insignificant effect on opening pressure.
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