Clinical History
Chronic daily headache and visual disorders (Right Eye(RE):3/10, Left Eye(LE):6/10). MRI diagnosis: pseudotumour cerebri. CSF opening pressure >40 cm of water, without cytological abnormalities. Treatment with acetazolamide and oral steroid: headache improvement, visual problems worsening. Lumbar catheter placement. An MRI was performed to assess the surgical treatment's outcome.
Imaging Findings
Preoperative MRI findings: posterior flattening of the globes, resulting in
shortening of the eyes. Dilation and tortuosity of the optic nerve sheath. Empty sella.
Postoperative MRI findings: resolution of the globe flattening. Normal appearance of the optic nerve bilaterally. Successful treatment resulted in resolution of the empty sella, with the pituitary reexpansion to normal size.
Discussion
Idiopathic intracranial hypertension (IIH) is a well known but under-investigated clinical entity with an unsolved pathophysiologic background. Hence its diagnosis and optimal management usually creates problems for clinicians. The terms "pseudotumour cerebri" and "benign intracranial hypertension" were originally applied to patients with increased intracranial pressure (ICP) in whom no tumour was found and whose course was believed to be benign [1].
However, this clinical picture is neither always benign nor related to a false tumour and therefore its terminology was changed to "idiopathic intracranial hypertension" [2]. On the other hand, Friedman et al. have recently proposed that the umbrella term "pseudotumour cerebri" should be used for the patients having ICP with unclear aetiology or secondary causes such as medications and other medical conditions [3].
The diagnostic characteristics of this syndrome were first defined by Dandy in 1937 [4] and were later formulated as "Modified Dandy Criteria" by Smith in 1985 [5]. These criteria were revised owing to the developments in neuro-imaging. Magnetic resonance imaging (MRI) or contrast-enhanced computerized tomography (CT) were recommended for IIH patients [6]. Friedman et al., who preferred to call the syndrome pseudotumour cerebri, proposed recently updated criteria for the diagnosis which required: papilledema, normal neurologic examination except for intracranial nerve abnormalities, neuroimaging findings including normal brain parenchyma and no abnormal meningeal enhancement on MRI, normal CSF composition and elevated lumbar puncture opening pressure (≥25 cm of water in adults) [3]. They also proposed that in the absence of papilledema, the diagnosis would be suggested if at least 3 of the following neuroimaging features were present additionally: 1) empty sella, 2) flattening of the posterior aspect of the globe, 3) distention of the perioptic subarachnoid space with or without a tortuous optic nerve, 4) transverse venous sinus stenosis [3].
The primary goal of treatment is decreasing ICP to preserve visual function and to eliminate headache. Our observation emphasises the importance of the initial lumbar puncture as a therapeutic procedure in addition to its diagnostic importance. Because of the visual disorders worsening, a lumbar catheter was placed. The patient improved immediatelly and the efficacious visual recovery was observed (RE: 9/10, LE: 9/10).
Differential Diagnosis List
Pseudotumor cerebri
hydrocephalus
all the causes of intracranial hypertension should be sought
