Dilatation of the Virchow-Robin space is a sensitive indicator of cerebral microvascular disease: study in elderly patients with dementia

Abstract

Background and purpose: Virchow-Robin spaces (VRSs) are CSF spaces that accompany blood vessels as they perforate the brain substance. Dilatation of VRS is associated with microangiopathy. Microvascular disease has a major etiologic and pathogenetic role in dementias. To our knowledge, no investigators have looked at the relationship between dilated VRS on MR imaging and cerebral microvascular disease. The aim of our study was to test the hypothesis that dilatation of VRS is associated with subcortical vascular dementia.

Methods: We recruited 75 patients with Alzheimer's disease (n = 35), ischemic vascular dementia (n = 24), or frontotemporal dementia (n = 16) and 35 healthy volunteers. We assessed deep white matter and periventricular hyperintensities and the severity of VRS dilatation, as scored on MR images. Statistical group comparisons and multiple regression analyses were performed to quantify the relationship between imaging features and diagnoses.

Results: White matter lesions were more common in patients with ischemic vascular dementia than in those with Alzheimer's disease or healthy volunteers (P < .01). VRS scores were significantly higher in patients with vascular dementia than in patients with AD (P < .001), patients with FTD (P < .01), or healthy volunteers (P < .001). VRS scores accounted for 29% of the variance in the regression model, and scores for periventricular hyperintensity accounted for 2%.

Conclusion: VRS dilatation is common in diseases associated with microvascular abnormality and can be used as a diagnostic tool to differentiate vascular dementias from degenerative dementias.

Fig 1.

Matching axial MR images show severe (grade 5) dilatation of the VRS (matrix = 256 × 256, FOV = 230 × 230 mm): A, T2-weighted variable echo (TR/TE1/TE2 = 5500/20/90); B, T1-weighted high-spatial-resolution T1-weighted 3D gradient echo (TR/TE = 24/18, section thickness = 0.89 mm, flip angle = 30°); and C, inversion recovery (TR/TE/TE = 6850/18/300). Calculated CNRs for VRS versus WM are 64.1 for inversion recovery, 24.8 for fast field-echo, 19.1 for the variable-echo second-echo imaging.

Fig 2.

Axial inversion recovery MR images (TR/TE/TI = 6850/18/300, matrix = 256 × 256, FOV = 230 × 230 mm) show grade 3 VRS dilatation (arrows).

Fig 3.

Axial inversion recovery MR images (TR/TE/TI = 6850/18/300, matrix = 256 × 256, FOV = 230 × 230 mm) show extensive VRS dilatation (arrows) throughout the BG (grade 5).

Fig 4.

Axial Inversion recovery MR images (TR/TE/TI = 6850/18/300, matrix = 256 × 256, FOV = 230 × 230 mm) show the VRS (arrows) as linear structure passing through several sections (A–C) in the imaging volume.