Analysis of prognostic factors in acute encephalopathy with biphasic seizures and late reduced diffusion: a retrospective study on MRI findings and the treatments

BACKGROUND: Acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) is a subtype of acute encephalopathy diagnosed based on its characteristic clinical course and imaging findings. However, AESD presents with various symptoms and diverse neurological outcomes. We aimed to identify prognostic factors for AESD by analyzing clinical data. METHODS: This retrospective study included patients diagnosed with AESD at our institution between 1997 and 2015. 57 patients (29 male and 28 female) were included for analysis, with a median age at onset of 13 months (interquartile range: 11-22 months). Short-term outcome was defined as neurological status at 6 months post-onset, and long-term outcome as status at more than 2 years post-onset. Patients were categorized into favorable (Pediatric Cerebral Performance Category [PCPC] 1-2) and unfavorable (PCPC 3-6) outcome groups. We reviewed the clinical course, laboratory data (blood and cerebrospinal fluid during the early and late seizure phases), magnetic resonance imaging (MRI) findings, and treatment interventions. Univariate and multivariate logistic regression analyses were conducted to identify prognostic factors (p < 0.05 was considered statistically significant). RESULTS: In the multivariate analysis, extensive MRI lesions were significantly associated with poor short-term outcomes (p = 0.009, odds ratio [OR] 8.333), while edaravone use was significantly associated with favorable long-term outcomes (p = 0.007, OR 0.105). CONCLUSIONS: The extent of MRI lesions predicted short-term outcomes, while edaravone administration was associated with improved long-term outcomes in patients with AESD.