Cerebrovascular disorders in the prenatal period

Fetal stroke can occur between the 14th week of pregnancy and the beginning of labor. The incidence is approximately 17-35 of 100,000 live births. Risk factors are correlated to the mother, the pregnancy, or the factors associated with the fetus itself. Computerized tomography and magnetic resonance imaging are the most commonly used imaging techniques. The authors studied 3 cases with neurological symptoms by magnetic resonance imaging and magnetic resonance-angiography. In these cases, the authors found massive involvement of the left hemisphere that was presumptively correlated with the persistence of the oval foramen. Magnetic resonance-angiography showed a flow reduction in the left cerebral vessels, and in 1 case, there was also persistence of the fetal primitive trigeminal artery. The discrepancy between the extent of the cerebral lesions and the neurological symptoms is associated with cerebral plasticity, which is greater in damage occurring early in fetal life

Posterior reversible encephalopathy syndrome associated with methotrexate neurotoxicity: conventional magnetic resonance and diffusion-weighted imaging findings

The addition of intrathecal methotrexate to treatment protocols has increased survival rates in children with acute lymphoblastic leukemia but is also associated with varying degrees of neurotoxicity. We describe a 15-year-old female patient diagnosed with acute lymphoblastic leukemia presenting with status epilepticus after receiving intrathecal methotrexate. Magnetic resonance imaging showed reversible cortical and subcortical changes consisting of high-intensity lesions on T2-weighted and fluid-attenuated inversion recovery sequences with postgadolinium enhancement, low signal intensity on diffusion-weighted imaging and increased apparent diffusion coefficient. These findings were consistent with the posterior reversible encephalopathy syndrome. We report our conventional magnetic resonance and diffusion-weighted imaging findings and briefly discuss the pathophysiology of the syndrome