Influence of hemodynamics on enlarged perivascular spaces in atherosclerotic large vessel disease.

Objectives: Enlarged perivascular spaces (EPVS) are often observed in small vessel disease on T2-weighted images. However, their role in ischemic conditions caused by cerebral large vessel disease remains unclear. We evaluated EPVS in patients with hemodynamic compromise associated with atherosclerotic large vessel disease and aimed to identify the pathophysiology of EPVS.
Methods: We examined 28 adults with atherosclerotic large vessel disease. EPVS numbers in the basal ganglia and the centrum semiovale were assessed. For each affected hemisphere, the total numbers of EPVS were compared with those on the unaffected side. EPVS in the impaired hemodynamics group were compared with those in the unimpaired hemodynamics group. Moreover, EPVS were compared in the presence/absence of large stroke.
Results: The number of EPVS was significantly increased on the affected side in the centrum semiovale (p = 0.023), particularly in the impaired hemodynamics group (p = 0.006). Moreover, in the small stroke subgroup of the impaired hemodynamics group, the number of EPVS was significantly increased on the affected side (p = 0.002), although this number was insignificant in the large ischemic stroke subgroup.
Conclusions: The number of EPVS was increased in patients with atherosclerotic large vessel disease with hemodynamic compromise and decreased in the presence of a large stroke. EPVS might act as fluid absorbers in a hemodynamically compromised state until the occurrence of an ischemic stroke.