Increased interstitial fluid in periventricular and deep white matter hyperintensities in patients with suspected idiopathic normal pressure hydrocephalus

• Published in: Scientific reports Vol. 11; no. 1; p. 19552
• Main Authors: Rau, Alexander, Reisert, Marco, Kellner, Elias, Hosp, Jonas A., Urbach, Horst, Demerath, Theo
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.10.2021; Nature Publishing Group; Nature Portfolio
• Subjects: 631/378/1689; 631/378/1689/364; 692/617/375/599; Aged; Aged, 80 and over; Biomarkers; Diffusion; Disease Susceptibility; Extracellular Fluid - metabolism; Female; Humanities and Social Sciences; Humans; Hydrocephalus; Hydrocephalus, Normal Pressure - diagnostic imaging; Hydrocephalus, Normal Pressure - etiology; Hydrocephalus, Normal Pressure - metabolism; Hydrocephalus, Normal Pressure - pathology; Image Processing, Computer-Assisted; Magnetic Resonance Imaging - methods; Male; multidisciplinary; Neurodegeneration; Neuroimaging; Organ Size; ROC Curve; Science; Science (multidisciplinary); Substantia alba; Water content; White Matter - diagnostic imaging; White Matter - metabolism; White Matter - pathology; White Matter - ultrastructure
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-021-98054-0

Periventricular white matter changes are common in patients with idiopathic normal pressure hydrocephalus (iNPH) and considered to represent focally elevated interstitial fluid. We compared diffusion measures in periventricular hyperintensities in patients with imaging features of iNPH to patients without. The hypothesis is that periventricular hyperintensities in patients with presumed iNPH show higher water content than in patients without imaging features of iNPH. 21 patients with iNPH Radscale 7–12 (“high probability of iNPH”) and 10 patients with iNPH Radscale 2–4 (“low probability of iNPH”) were examined with a neurodegeneration imaging protocol including a diffusion microstructure imaging sequence. Periventricular hyperintensities and deep white matter hyperintensities were segmented and diffusion measures were compared. In patients with imaging features of iNPH, the free water content in periventricular hyperintensities was significantly higher compared to the control group ( p  = 0.005). This effect was also detectable in deep white matter hyperintensities ( p  = 0.024). Total brain volumes and total gray or white matter volumes did not differ between the groups. Periventricular cap free water fraction was highly discriminative regarding patients with presumed iNPH and controls with an ROC AUC of 0.933. Quantitative diffusion microstructure imaging shows elevated water content in periventricular hyperintensities in patients with imaging features of iNPH, which could be the imaging correlate for pathologic fluid accumulation and may be used as an imaging biomarker in the future.