[Clinical relevance of normal and enlarged Virchow-Robin spaces]

Virchow-Robin spaces ensheathe the penetrating vessels of the brain. They communicate with the subpial space, are filled with interstitial fluid and contain a specific population of macrophages.Virchow-Robin spaces are a common finding in both CT and MR imaging. Recent radiologic studies have led to a concise definition of Virchow-Robin spaces.Virchow-Robin spaces appear isointense to cerebrospinal fluid on all imaging sequences. They are typically localised in the basal ganglia, subcortically or in the midbrain and pons. Enlarged Virchow-Robin spaces may appear as a single or multiple lesion(s). They may cause hydrocephalus in rare cases. Some studies indicate that enlarged Virchow-Robin spaces occur more frequently in elderly patients, in patients with arterial hypertension or CADASIL.In this review we illustrate the diagnostic criteria of normal and enlarged Virchow-Robin spaces and discuss their clinical relevance. Furthermore, we present an overview of the current knowledge on the anatomy, physiology and pathology of Virchow-Robin spaces.