Disease activity in idiopathic intracranial hypertension: a 3-month follow-up study

Idiopathic intracranial hypertension (IIH) is a disorder of raised intracranial pressure (ICP) in the absence of identifiable pathology. The purpose of this study was to evaluate the clinical presentation and monitor a 3-month course using frequent optical coherence tomography (OCT) evaluations, visual field testings and lumbar opening pressure measurements. A longitudinal study of 17 patients with newly diagnosed IIH and 20 healthy overweight controls were included in the study. Peripapillary retinal nerve fiber layer thickness (RNFLT) and retinal thickness (RT) measurements (Stratus OCT-3, fast RNFL 3.4 protocol), and Humphrey visual field testing were evaluated at regular intervals. Repeat lumbar puncture was performed at final visit (n = 13). The diagnostic delay was 3 months and initial symptoms were headache (94%), visual blurring (82%) and pulsatile tinnitus (65%). Complete clinical remission was achieved in 65%, partial in 29% and unchanged symptoms in 6%. Total average RNFLT and RT decreased significantly during the follow-up period (p < 0.0001 and p < 0.0001, respectively). Changes in RNFLT and RT correlated with improvements in visual field mean deviation (MD) (RNFLT: p = 0.006; RT: p = 0.03) and pattern standard deviation (PSD) (RNFLT: p = 0.002; RT: p = 0.003). In patients with weight-loss > 3.5% of BMI, ICP decreased significantly (p = 0.0003). In patients with weight-loss < 3.5% of BMI, changes in ICP were insignificant (p = 0.6). OCT combined with visual field testing may be a valuable objective tool to monitor IIH patients and the short term IIH outcome is positive. Weight-loss is the main predictor of a favorable outcome with respect to CSF pressure.