Early diffusion-weighted magnetic resonance imaging findings in neonatal herpes encephalitis.

Neonatal herpes encephalitis is usually caused by herpes simplex virus type 2 and results in significant morbidity and mortality. Imaging diagnosis with ultrasound, computed tomography scan and conventional magnetic resonance imaging may be normal in the early course of the disease. In this case diffusion-weighted magnetic resonance imaging detected the disease process earlier and better than the conventional T2-weighted or fluid-attenuated inversion recovery imaging sequences. The use of diffusion-weighted magnetic resonance imaging in neonatal herpes encephalitis proved to be a useful tool in the early stage of the disease.