Cystic Encephalomalacia in a Young Woman After Cardiac Arrest Due to Diabetic Ketoacidosis and Thyroid Storm.

Cystic encephalomalacia is commonly reported in neonates with prenatal or perinatal hypoxic events. It is rarely observed in adults. A 25-year-old woman with a history of type 1 diabetes mellitus and hyperthyroidism presented to the emergency department with diabetic ketoacidosis (DKA) and a thyroid storm. She sustained cardiac arrest due to ventricular fibrillation and subsequently developed hypoxic encephalopathy. Initial brain computed tomography showed no significant findings; however, follow-up magnetic resonance imaging three months later revealed cystic encephalomalacia in the bilateral parieto-occipital lobes. A Tc-99m ethyl cysteinate dimer (ECD) brain perfusion scan revealed extensive hypoperfusion in the bilateral frontal and parieto-occipital lobes. She showed severe cognitive impairment and marked spasticity in all her limbs. Although cystic encephalomalacia is mostly reported in neonates with hypoxic injury, it can be seen in adults with hypoxic encephalopathy, leading to a significant neurological deficit.