Virchow-Robin spaces in idiopathic normal pressure hydrocephalus: a surrogate imaging marker for coexisting microvascular disease?

BACKGROUND

Virchow-Robin spaces (VRSs) surround perforating cerebral arteries and are reported to be found with increasing frequency with advancing age. In addition, some studies indicate an association between VRSs and vascular dementias. The present study examined the incidence of VRSs in patients with idiopathic normal pressure hydrocephalus (INPH) and considered their use as a potential surrogate imaging marker of coexisting microvascular disease in patients with this condition.

METHODS

The MRI incidence of VRS in the centrum semiovale (CS), basal ganglia (BG), mesencephalon (MES), and the subinsular (SI) region was measured in 12 patients with INPH and in 12 control subjects, using the scoring system proposed by Patankar et al. (Am J Neuroradiology 26:1512, 2005). Historical control data were also used for further comparison.

RESULTS

All 12 INPH patients had clearly visible VRSs, distributed in the CS (all 12), basal ganglia (11/12), SI region (9/12), and MES region (6/12). The mean Patankar scores of the INPH group were BG 2.25, CS 1.66, SI 0.91, and ME 0.5. The respective scores for our control group were 1.41, 1.5, 1.16, and 0.16, and for historical controls were 1.46, 0.51, 0.96, and 0.51. There were, however, no statistically significant differences between the INPH patients and either of the control groups. No correlation was found between age and the overall incidence of VRS.

CONCLUSION

This preliminary study suggests that there may be a higher incidence of VRSs in patients with INPH, when compared with normal patients of similar age, but our small numbers prevent us from demonstrating statistical significance, and larger studies are clearly required.