Idiopathic Intracranial Hypertension: Current Neuroophthalmologic Points

Abstract

Idiopathic intracranial hypertension (ICH) is a neuroophophthalmologic syndrome, the main ophthalmologic symptoms of which are vision loss and bilateral swelling of optic nerve disks (OD). The article provides a review covering various aspects of ICH. Epidemiology: ICH occurs mainly in women aged 20–45 years with body overweight. In this group of patients world incidence is 12–20 per 100 000 of population per year. In the total population it represents 0.5–2 cases per 100 000 of population per year. The eightfold gender predominance of women with ICH is observed. Etiology is not fully known until present time. The reliable connection between obesity in childbearing age women and menstrual cycle disorders as evidences of hormonal changes has been established. The probable mechanisms of increase of ICP are supposed: hyperproduction of and disturbances of its absorption, CSF mechanical pressure on the optic nerve sheath; restriction of venous outflow from the brain due to the pathology of venous sinuses; stimulating effect of abundant vitamin A in diet resulting in the fat tissue formation with the development of obesity; expression of the protein aquaporin, involved in the regulation of body mass and water metabolism in the subarachnoid space. Clinical manifestations. Ophthalmologic symptoms of ICH: transient visual impairment, sustained loss of visual acuity, photopsy, retrobulbar pain, diplopia. Non-ophthalmologic symptoms: headache, throbbing tinnitus, hearing loss, dizziness. Diagnostics. The valuable diagnostic data can be obtained by visual field investigation, ophthalmoscopic examination with revealing of bilateral OD-edema, OD and retinal optical coherent tomography, orbital ultrasound examination, brain MRI with venography. Treatment. Non-drug therapy: weight loss, lowcalorie diet with limited water and salt intake. Drug therapy: long-term oral use of carbonic anhydrase inhibitors (acetazolamide, topiramate). High doses of steroids (methylprednisone) are used for short-term treatment of patients with fulminant disease type before surgery. Surgery: bypass surgery, cerebral venous sinus stenting and fenestrations of the optic nerve sheath: bariatric surgery with reducing of stomach volume.