Involuntary movements as a prognostic factor for acute encephalopathy with biphasic seizures and late reduced diffusion

Acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) is characterized by biphasic seizures and white matter lesions with reduced diffusion, which are often accompanied by involuntary movements. The neurological outcomes of AESD vary from normal to mild or severe sequelae, including intellectual disability, paralysis, and epilepsy. The present study aimed to clarify the prognostic factors of AESD, including involuntary movements. We enrolled 29 patients with AESD admitted to Tottori University Hospital from 1991 to 2020 and retrospectively analyzed their clinical data. Neurological outcomes were assessed by the Pediatric Cerebral Performance Category score and cerebral paralysis as neurological sequelae. Of the 29 patients, 12 had favorable outcomes and 17 had unfavorable outcomes. Univariate analysis revealed that the presence of underlying diseases, a decline in Glasgow Coma Scale (GCS) score 12–24 h after early seizures, and involuntary movements were associated with unfavorable outcomes. In multivariate analysis, a decline in GCS score and involuntary movements were associated with unfavorable outcomes. The sensitivities and specificities of underlying diseases, a decline of ≥ 3 points in GCS score 12–24 h after early seizures, and involuntary movements for unfavorable outcomes were 53% and 92%, 92% and 65%, and 59% and 92%, respectively. The appearance of involuntary movements may be associated with unfavorable outcomes of AESD. The prognostic factors identified herein are comparable with previously known prognostic factors of consciousness disturbances after early seizures.