Acute necrotizing encephalopathy (ANEC) is a rare, severe, immune-mediated brain condition in children under 5 years of age . Delayed identification and treatment lead to poor outcomes, with mortality rates up to 30% and lasting disabilities, including epilepsy, movement disorders, or cognitive impairment in up to 83% of cases.

Case 1:

A 3-year-old girl presented with rapid decline in sensorium within 24 hours of onset of an acute febrile illness with 2 episodes of generalized tonic-clonic seizures lasting for 2-3 minutes. She was intubated due to rapid decline in sensorium (GCS 8/15). MRI revealed bilateral thalamic necrotizing lesions, leading to an ANEC diagnosis. Treatment included supportive care, tocilizumab (12mg/kg), and pulse methylprednisolone (30mg/kg) within 36 hours. She showed dramatic improvement, was extubated on Day 7, and recovered completely without neurological deficits.

Case 2: A 2-year-old boy presented with 13 days of fever, 10 days of cough, and one episode of left arm tonic-clonic seizure. He had altered consciousness (GCS 8/15). Brain MRI revealed bilateral deep gray matter and brainstem changes, suggesting early ANEC. Treatment included supportive therapy, tocilizumab 12mg/kg, and pulse methylprednisolone 30mg/kg for 3-5 days within 24 hours of onset of illness. No deficits noted on short term follow up.