Early onset cerebral oedema in adult diabetic ketoacidosis with complete resolution

Cerebral oedema is a rare and potentially lethal complication of diabetic ketoacidosis (DKA). While more commonly reported in the paediatric population, adult cerebral oedema in the setting of DKA remains poorly understood and under-recognised. We present the case of a woman in her late 20s who was brought to the emergency department with severe DKA and altered mental status. Her imaging demonstrated diffuse cerebral oedema with effacement of sulci and basal cisterns. Notably, the oedema was identified before significant metabolic correction had occurred, suggesting that cerebral oedema may have been a direct consequence of DKA rather than a complication of its treatment. The patient received fluid resuscitation, insulin infusion and hyperosmolar therapy, and recovered fully without neurosurgical intervention. This case highlights the importance of early recognition and intervention for cerebral oedema in adult DKA, especially in patients presenting with severe acidosis and neurologic changes.