Virchow-robin spaces in health and disease.

Virchow-Robin spaces are pial-lined, interstitial fluid-filled structures that do not directly communicate with the subarachnoid space, and accompany penetrating arteries and veins. They are common, incidental, "leave me alone" lesions that should not be mistaken for more ominous disease. They are frequently seen in the supratentorial white matter, basal ganglia region, around the anterior commissure, and surrounding penetrating lenticulostriate arteries, thalamus, midbrain, cerebellum, insular cortex, corpus callosum, cingulate gyrus, extreme capsule, along the optical tracts, and in the hippocampus. Most are small, well-defined fluid-filled cysts less than five mm in diameter, and are isointense to CSF on all pulse sequences. They are often mistaken for lacunar infarcts, cystic neoplasms or infectious cysts. We retrospectively analyzed various appearances of VRS as seen on magnetic resonance imaging of brain in 100 cases, in an attempt to provide a better understanding of these lesions and their significance in various physiological and pathological conditions.