Diagnosis and management of benign intracranial hypertension

Benign intracranial hypertension (BIH) is a headache syndrome characterised by (1) raised cerebrospinal fluid (CSF) pressure in the absence of an intracranial mass lesion or ventricular dilatation; (2) normal spinal fluid composition; (3) usually normal findings on neurological examination except for papilloedema and an occasional VI nerve palsy; and (4) normal level of consciousness. The appellation “benign” means not fatal. The syndrome can, however, disrupt normal life and cause significant visual failure. It is an uncommon condition in childhood presenting about once or twice a year in a large referral hospital. Early recognition is important as timely intervention may preserve vision and enables the doctor to start the appropriate treatment to control headaches. Children as young as 4 months can be affected; sex distribution is equal.1 2 Which intracranial compartment is primarily responsible for raising CSF pressure in the absence of ventricular dilatation is still unclear. Theories of BIH pathophysiology have been based on neuroradiological studies on patients with BIH (computed tomograms, magnetic resonance imaging (MRI), magnetic resonance diffusion scans, and radioisotope cisternography) and CSF hydrodynamic studies. These include increased venous sinus pressure, decreased spinal fluid absorption, increased spinal fluid secretion, increased blood volume, and brain oedema.3 4 Since the first large report on childhood BIH in 1967, reports subsequently show a changing clinical picture over time in terms of possible aetiology and clinical presentation.5 6Diagnosis is not always simply achieved. BIH can occur in the absence of papilloedema; a “normal resting” CSF pressure does not exclude the diagnosis in the presence of suggestive symptoms and signs.7 8 Review of our cases over the past 10 years confirms the wide clinical spectrum of this condition. Of the 22 cases seen, 15 presented with the classical picture of headaches, papilloedema, and a raised CSF pressure of …