DWI scoring system for prognosis of acute encephalopathy with biphasic seizures and late reduced diffusion.

Purpose: The aim of this study was to predict neurological outcomes for acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) using diffusion-weighted imaging (DWI), and assess relationships between anatomical sites of lesions and their outcomes.
Materials and Methods: We assessed DWI abnormalities and neurological outcomes in 30 patients with AESD, and classified patients into severe and non-severe groups according to their neurological outcomes. We also established a DWI scoring system as follows: zero for normal, and one for lesion at each location. Differences between the severe and non-severe groups were examined, and receiver operating characteristic (ROC) curve analysis was performed.
Results: Nine (30%) patients were classified into the severe group. On DWI, patients in the severe group were more likely to have temporal lobe (P = 0.014), perirolandic (P = 0.008), and corpus callosum (P = 0.0008) lesions than those in the non-severe group. The total DWI scores were significantly higher in the severe group than those in the non-severe group (P = 0.0002). ROC curve showed an area under the curve of 0.929, with a cutoff value of five, sensitivity of 88.9%, and specificity of 81.0%.
Conclusion: Patients with severe AESD had more extensive DWI abnormalities than those with non-severe AESD. Our DWI scoring system may be useful for the prediction of outcomes of AESD. Widespread lesions seemed to have stronger influence on outcomes than each lesion location.