Article Text
Abstract
Background Idiopathic intracranial hypertension (IIH) is a complex neurological disease characterized by symptoms of raised intracranial pressure of unclear etiology. Although the cause is generally considered multifactorial, an exact understanding of IIH pathophysiology remains elusive. The purpose of this study was to investigate how IIH clinical severity is related to MRI brain volume and CSF dynamics.
Methods IIH patients were identified from 2016–2023 from our tertiary care healthcare system. Brain MRIs were computationally segmented using FreeSurfer software. Measures of CSF homeostasis (total ventricle, choroid plexus (CP), and extraventricular CSF volumes) and total normalized brain volume (TBV), including gray matter (GM) and white matter (WM), were calculated and normalized to account for head size. Associations between clinical severity of Frisen papilledema grade and lumbar puncture opening pressure (OP) with brain volume and measures of CSF homeostasis were assessed.
Results In total, 89 IIH patients (88% female; mean age: 29.7 years, SD:8.3) met full inclusion criteria.In this population, decreased total brain volume was associated with increased grey matter (P<0.0001, R=0.42) and decreased white matter (P<0.0001, R=0.63). Decreased TBV was also associated with increases in all CSF related compartments: choroid plexus (P<0.0001, R=0.44), extraventricular CSF (P<0.0001, R=0.97), and total intraventricular volume (P<0.0001, R=0.40).Brain volumes were also associated with clinical severity in IIH; declining TBV (P=0.013, R=0.28), increasing GM (P=0.026, R=0.26), and increasing extraventricular CSF (P=0.016, R=0.28) were associated with worsening papilledema. Increasing GM was also associated with increased opening pressure (P=0.038, R=0.22), although other factors associated with papilledema were not.
Conclusion Overall, these findings suggest that changes in brain volume, particularly in GM, and alterations in CSF homeostasis may play important roles in the pathophysiology and clinical presentation of IIH.
Disclosures A. Finkelstein: None. D. Schartz: None. S. Akkipeddi: None. D. George: None. T. Furst: None. V. Dhar: None. N. Ellens: None. C. Houk: None. P. Valdes Barrera: None. Z. Williams: None. E. Vates: None. J. Zhong: None. M. Bender: None.