Asymmetric Papilledema in Idiopathic Intracranial Hypertension

Abstract

Background Very asymmetric papilledema in idiopathic intracranial hypertension (IIH) is rare, and few studies have dealt with this atypical presentation of IIH. Our aim was to describe the clinical and radiologic features of patients with IIH and very asymmetric papilledema. Methods We identified all adult patients from our IIH database with very asymmetric papilledema defined as a ≥2 modified Frisén grade difference between the two eyes. Demographic data and initial symptoms were collected, and all brain imaging studies performed at our institution were reviewed. Results Of the 559 adult patients with definite IIH, 20 (3.6%; 95%CI: 2.3-5.6%) had very asymmetric papilledema at initial evaluation. They were older (39 versus 30 years; p<0.001), had lower cerebrospinal opening pressure (35.5 versus 36 cm of water; p=0.03), and were more likely to be asymptomatic compared to patients with symmetric papilledema (27% versus 3%; p<0.001). Visual fields were worse on the side of the highest-grade papilledema (p=0.02). The bony optic canal was smaller on the side of the lowest-grade edema in all 8 patients (100%) in whom the imaging was sufficient for reliable measurements (p=0.008). Conclusion IIH with very asymmetric papilledema is uncommon. Very asymmetric papilledema may result from differences in size of the bony optic canals, supporting the concept of compartmentation of the peri-optic subarachnoid space.

Detection of Papilloedema Study (DOPS): rates of false positive papilloedema in the community

“…In our study, the detection of papilloedema by fundus photography was extremely sensitive, even among EM physicians, consistent with previous reports [16,[23][24][25]. That three raters missed the same case of unilateral papilloedema suggests a need to highlight that papilloedema may be asymmetric [26]. The exponential reduction in FPE rates with a requirement for increasing agreement, suggests that second and third opinions from ophthalmology or neurology colleagues may help differentiate papilloedema from FPE.…”

Spaceflight associated neuro-ocular syndrome (SANS) and the neuro-ophthalmologic effects of microgravity: a review and an update

“…Second, most cases of terrestrial IIH present with bilateral and symmetric disc edema with highly asymmetric or unilateral disc edema documented in only 3-10% of IIH patients. 15,16 In contrast, of five astronauts with ODE following LDSF in our 2011 report, one displayed highly asymmetric ODE, two had strictly unilateral ODE and only two displayed symmetric ODE. Third, if venous stasis from microgravity induced cephalad fluid shifts was solely responsible for astronaut disc edema we would expect this edema to quickly resolve following a return to the 1 G environment.…”

Flow dynamics of cerebrospinal fluid between the intracranial cavity and the subarachnoid space of the optic nerve measured with a diffusion magnetic resonance imaging sequence in patients with normal tension glaucoma

“…Narrowing of the subarachnoid space (SAS) and obstruction of the CSF pathway results in reduction of CSF flow, supporting the optic nerve (ON) compartmentation process . This influences the CSF flow between the SAS of the ON and the intracranial cisterns, affecting the CSF dynamics along the ON …”