UNILATERAL PAPILLEDEMA DUE TO IDIOPATHIC INTRACRANIAL HYPERTENSION: A CASE REPORT

Introduction: Papilledema is highly predicted and common to encounter in all causes of raised intracranial pressure including idiopathic intracranial hypertension; it is usually bilateral and symmetrical. Unilateral and asymmetrical papilledema is considered highly atypical and a rarity of presentation, posing significant diagnostic challenge to the poorly understood pathological phenomenon of IIH. Case: We report a 40-year-old African female with idiopathic intracranial hypertension who fully fulfills the Modified Danddy Criteria; presenting with unilateral papilledema, with Left eye fundoscopic examination showing extensively hyperemic and swollen optic disc with an associated tortuously engorged retinal vein. Brain imaging via MRI revealed partial empty sella, bilateral prominent fluid signal projection that is more evident in the left optic nerve sheath and a prominent meckel's cave on the left side measuring (6.1 mm) in the transverse diameter. MRA concluded an attenuated most lateral side of the left transverse sinus. Lumbar puncture was attempted and revealed an opening pressure of (45 cmH2O), and otherwise normal CSF cytology and chemical composition. Significant symptomatic relief was depicted upon lumbar puncture. Discussion: papilledema is universally encountered as a bilateral and symmetrical phenomenon; thus, presentation of IIH with unilateral papilledema has been under extensive research recently in attempts to contemplate the exact pathophysiology. Amongst many other proposed theories, we endorse the variation of the optic canal diameter as a potential mechanism for asymmetry of papilledema in IIH. As larger optic canal diameter is postulated to be associated with higher CSF pressure force transduction with subsequent optic nerve damage. Conclusion: Unilateral and asymmetrical papilledema is considered substantially unique and anecdotal rarities of presentation of IIH; posing a significant diagnostic troublesome and dilemma. Physicians should be aware and highly vigilant of such deviations of usual presentations to avoid consequential diagnostic and management adverse outcomes and unwanted complications.