Pseudotumor cerebri (PTC) is an entity characterized by elevated intracranial pressure with normal cerebrospinal fluid (CSF) and no structural abnormalities detected on brain MRI scans. The neurological symptoms and signs can be totally attributed to intracranial hypertension, and these include headaches, transient visual obscurations, visual loss and intracranial tinnitus, papilledema being the hallmark of PTC. This syndrome includes both idiopathic and secondary causes. Common secondary causes include endocrine pathologies. Thyroid disturbances have a unique correlation, since hypothyroidism, hyperthyroidism and thyreostimulin suppression hormone therapy have all been reported in association with this disorder. Hyperthyroidism is very rarely associated with the disorder and only three case reports [1–3] have been published to date, one of them [3] in association with hypovitaminosis A.

Considering that other causes were excluded and there was neurological improvement once hyperthyroidism treatment was started, a relationship between hyperthyroidism and PTC can be assumed. Although acetazolamide was also used during the symptomatic phase, and this could represent a confounder, we are convinced that the thyroid disease treatment was the major reason for improvement. This is a rare form of presentation of Graves' disease and a rare cause of PTC.

The pathophysiologic basis of PTC is still a matter of debate, but a relationship has been established [4, 5] with elevated intracranial venous pressure. The increase in resistance of CSF absorption is thought to be caused by an insufficiently high driving pressure gradient from the subarachnoidal space to the venous system. Thyroxine, being a major regulator of sodium transport, can contribute to altered CSF dynamics. The effect of thyroid hormone raising venous pressure may justify the association between those two entities. In fact, there is a previously reported association between thyrotoxicosis and cerebral vein thrombosis [6], with additional procoagulant influences probably required in such cases.

We would like to emphasize that hyperthyroidism should be considered among the causes of PTC and that this association should be given further attention. Optic fundus examination with screening for papilledema in patients with thyroid diseases could detect more patients with intracranial hypertension, helping to prevent visual sequelae.

Written informed consent was obtained from the patient for publication of this case report and any accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal.