Brain versus orbital MRI in evaluating idiopathic intracranial hypertension

OBJECTIVE: To evaluate the usefulness of brain MRI as compared to orbital MRI in the assessment of idiopathic intracranial hypertension (IIH).

METHODS: The study was carried out at King Abdul-Aziz University Hospital, Jeddah, Kingdom of Saudi Arabia between January 2002 and December 2003. An MRI of the head and orbits was performed for 42 patients with the clinical diagnosis of IIH, and 15 normal volunteers. All cases of secondary increased intracranial pressure were eliminated. The images were evaluated for the presence of empty sella, parenchymal abnormalities, ventricular and sulcal size changes, optic disc elevation, and optic nerve sheath distention.

RESULTS: The MRI of the head revealed empty sella in 29 patients and in one normal volunteer. Brain MRI did not reveal any parenchymal, ventricular or cisternal abnormalities in either group. Orbital MRI revealed optic nerve sheath distension and optic disc elevation in 36 patients, and were normal in all volunteers.

CONCLUSION: Brain MRI has limited value in the evaluation of IIH. Orbital MRI is the recommended imaging modality for this entity.