Nihal Yıldız, Ezgi Genç Köroğlu
Journal of Emergency Medicine Case Reports - 2025;16(4):150-153
Acute encephalopathy is a rapidly progressive neurological condition characterized by seizures, altered mental status, and other neurologic abnormalities. One rare etiology of this presentation is Acute Leukoencephalopathy with Restricted Diffusion (ALERD), which typically occurs in early childhood. However, in rare instances, it may also present in older individuals. We present the case of a 17-year-9-month-old female admitted to the emergency department (ED) with acute-onset confusion, fixed gaze, and altered consciousness following a week of diarrhea, three days of insomnia and hearing loss, and one day of dis - orientation. On examination, she was lethargic, with a Glasgow Coma Scale (GCS) score of 12, absent pupillary light reflexes, and extensor plantar responses. Initial CT and MRI scans were normal. Cerebrospinal fluid (CSF) analyses were unremarkable, and a comprehensive toxicology panel was negative. Despite empirical antimicrobial and antiepileptic treatment, her condition did not improve. She was treated with pulse-dose methylprednisolone, followed by intravenous immunoglobulin (IVIG). On day four, diffusion-weighted MRI revealed significant periventricular diffusion restriction. Genetic analysis showed several mitochondrial DNA variants of uncertain significance (VUS). Immunomodulatory and metabolic treatments were administered, leading to a gradual neurological recovery over the following weeks and months. Although ALERD is typically observed in younger children, clinicians should be aware that it may rarely occur in adolescents. Emergency physicians should maintain a high index of suspicion for ALERD in patients with unexplained encephalopathy, especially when initial imaging is normal but symptoms progress. Prompt diagnosis and immunotherapy may prevent long-term neurological sequelae.
