Unfortunate Case of Hypoglycemia Induced Seizures Resulting in Anoxic Encephalopathy

Background: Severe hypoglycemia in patient with diabetes mellitus can manifest as seizures and coma, most commonly occurring after excessive insulin administration. Clinical Case: A 35-year-old woman with uncontrolled type 1 diabetes mellitus on basal-bolus insulin, complicated by gastroparesis, hypoglycemia unawareness, and frequent hypoglycemic episodes due to a tendency to give more than the recommended amount of insulin, who presented with seizures and diffuse brain edema as severe manifestations of profound hypoglycemia. Hemoglobin A1c was 7.3% but patient had wide variation in blood glucose (40- 300 mmol/L) on her glucometer. Patient had initially self-treated overnight hypoglycemic symptoms by drinking soda and then fell asleep without re-checking her blood sugar. She was then unresponsive in the morning. Patient’s husband reported that there was no glucagon at home since he used the last one and did not refill. On EMS arrival, patient had a blood glucose of 25, for which she received dextrose and glucagon with improvement of blood glucose but no change in mentation. En route to the hospital, patient developed tonic-clonic seizures and decerebrate posturing. She received Ativan and was intubated for airway protection. On exam, she had bilateral dilated sluggishly reactive pupils, eyes opened spontaneously but did not track, and limbs moved spontaneously but there was no purposeful movement. Initial CT head without contrast showed significant diffuse brain edema. Repeat MRI brain with and without contrast showed bilateral basal ganglia diffusion restriction with associated T2 and FLAIR hyperintense signal, suggestive of toxic-metabolic etiology including hypoglycemia. Video EEG showed findings consistent with anoxic encephalopathy. Patient received IV mannitol and IV dexamethasone for cerebral edema and Keppra for seizure prophylaxis, but was unable to be weaned from the ventilator and had to undergo tracheostomy and PEG tube placement, and was eventually discharged to inpatient rehabilitation. Conclusion: This case highlights the dangers of accidental overcorrection of high blood sugar with short-acting insulin and not appropriately treating hypoglycemia, which can lead to irreversible brain injury due to prolonged hypoglycemia. This unfortunate case highlights the importance of educating patients with diabetes mellitus on insulin how to appropriately manage low sugars to avoid such outcomes.