| Abstract: | Three cases with cavitary lesions on the cerebral convexities in twin gestation complicated by a single intrauterine fetal demise were investigated clinicopathologically. They all exhibited profound mental retardation and severe motor disturbance due to rigidospastic tetraplegia. The co-twins were macerated. Neuropathologically, malformed lesions and destructive lesions coexisted in varying degrees according to the time in fetal life, at which insults probably occurred. The cavitary lesions were located bilaterally and symmetrically on the central, parietal and occipital region of the cerebral hemispheres, in some cases, including the frontal region. Case 1 showed an incomplete gyral pattern and porencephaly with polymicrogyria bordering the defect, thus allowing us to date the insult before the 5th fetal month. In case 2, multicystic encephalomalacia was disclosed with cortical dysgenesis exhibiting status marmoratus of the cortex. Case 3 displayed sclerotic cavitary lesions with sclerosis of the insula and a few instances of cortical dysgenesis. Based on the clinical data and pathological findings, the cavitary lesions of case3 may be dated in the third trimester of gestation. Case 2 can be considered to have sustained injuries between the times estimated for cases 1 and 3. As the pathogenesis of the congenital cavitary lesions, several concepts have been proposed: intrauterine DIC (Moore et al. 1969;Romero et al. 1984), vascular disruption (Hoyme et al. 1981;Jung et al. 1984), intrauterine infection such as cytomegalic inclusion disease (Friede et al. 1976), and hypoxia due to CO intoxication of the mother (Bank1 et al. 1967) or other cause. Though the pathological observation of our cases revealed no evidence of intrauterine DIC, renal cortic necrosis, intrauterine infection or occlusion of the intracranial vessels, long-term exposure to the dead twin might have contributed to the lesions of the liveborn co-twin. |
