Abstract
Pathogenesis of periventricular lucency was investigated. Periventricular lucency noted in acute hydrocephalus may represent periventricular edema and disappears in a short time after a shunting operation. Periventricular lucency in chronic and normal pressure hydrocephalus is presumed to be a consequence of water retention combined with a disturbance of the blood circulation in the white matter. Periventricular lucency in hydrocephalus is considered to be a reversible phenomenon and may be regarded as a sign of present or preceding intraventricular hypertension. It may provide a useful criterion for a shunting operation. Periventricular lucency encountered in diseases other than hydrocephalus is supposed to be leukoencephalopathy in the arterial borderzone which is vulnerable to hypoxic-ischemic events. These two different periventricular lucencies should be differentiated.
