Many reversible brain MRI abnormalities have been described, among these the mostfrequently reported are cortical hyperintensities on FLAIR/T2 occurring during seizures.Much less attention has been given to those situations where White Matter goes Dark. In the most recent review of the literature about seizure-induced brain MRI abnormalities, the “Dark White Matter” sign, or Diffuse Subcortical White Matter Low Intensity on T2/FLAIR, has been reported only once so far. The largest case series on Dark White Matter included 29 patients, the majority of which (75.9%) reported seizures and almost half of them had associated extrinsic compressive lesions, such as subdural hematoma (SDH), which was the most frequent concomitant pathology, reported in 41.8% patients. Our aim is to identify the medicalcondition “Dark White Matter” (DWM) is more frequently associated with. This is the first systematic review on DWM.