Widening spectrum of a reversible splenial lesion with transiently reduced diffusion

Abstract

Four patients with encephalitis/encephalopathy and parenchymal lesions accompanying reversible splenial lesions were retrospectively evaluated. In 3 patients, reversible lesions with transiently reduced diffusion were seen in the splenium and symmetrically in the peripheral frontoparietal white matter, clinical signs and symptoms were mild, and recovery was complete. These and previous observations suggest a less severe course and outcome for patients with reversible lesions isolated to the splenium or to the splenium and peripheral frontoparietal white matter.

Fig 1.

Diffusion-weighted and T2-weighted images of patient 2 on day 5 showed high-signal-intensity lesions in the central portion of the splenium of the corpus callosum (SCC) and symmetric frontoparietal peripheral white matter (A–C, arrows). Follow-up study on day 12 showed no lesions on any sequences (T2-weighted image, D).

Fig 2.

Diffusion-weighted image (DWI) of patient 4 on day 2 showed an oval shaped splenial lesion (A). DWI on day 7 showed no splenial lesion, but frontal cortical lesions with reduced diffusion (B, arrows), followed by cortical T2 prolongation and atrophy on day 70 (fluid-attenuated inversion recovery, C).