Objective: To describe a case series of adult patients in the intensive care unit in super-refractory status epilepticus (SRSE; refractory status lasting 24 hours or more despite appropriate anesthetic treatment) who received treatment with the ketogenic diet (KD). Methods:We performed a retrospective case review at 4 medical centers of adult patients with SRSE treated with the KD. Data collected included demographic features, clinical presentation, diagnosis, EEG data, anticonvulsant treatment, and timing and duration of the KD. Primary outcome measures were resolution of status epilepticus (SE) after initiation of KD and ability to wean from anesthetic agents.Results: Ten adult patients at 4 medical centers were started on the KD for SRSE. The median age was 33 years (interquartile range [IQR] 21), 4 patients (40%) were male, and 7 (70%) had encephalitis. The median duration of SE before initiation of KD was 21.5 days (IQR 28) and the median number of antiepileptic medications used before initiation of KD was 7 (IQR 7). Ninety percent of patients achieved ketosis, and SE ceased in all patients achieving ketosis in a median of 3 days (IQR 8). Three patients had minor complications of the KD including transient acidosis and hypertriglyceridemia and 2 patients ultimately died of causes unrelated to the KD. Conclusion:We describe treatment of critically ill adult patients with SRSE with the KD, with 90% of patients achieving resolution of SE. Prospective trials are warranted to examine the efficacy of the KD in adults with refractory SE. Classification of evidence:This study provides Class IV evidence that for intensive care unit patients with refractory SE, a KD leads to resolution of the SE. Neurology ® 2014;82:665-670 GLOSSARY AED 5 antiepileptic drug; GCS 5 Glasgow Coma Scale; ICU 5 intensive care unit; IQR 5 interquartile range; KD 5 ketogenic diet; LOS 5 length of stay; MAD 5 modified Atkins diet; RSE 5 refractory status epilepticus; SE 5 status epilepticus; SRSE 5 super-refractory status epilepticus.Super-refractory status epilepticus (SRSE) is defined as status epilepticus (SE) that continues for at least 24 hours after initiation of general anesthetic medications, including cases in which the SE recurs with reduction or withdrawal of anesthesia.1 SRSE holds a high risk of morbidity and mortality and has been associated with conditions such as encephalitis, anoxic brain injury, and intracranial hemorrhage. The ketogenic diet (KD) and modified Atkins diet (MAD) are high fat, low carbohydrate, adequate protein diets designed to mimic the fasting state that have been proven as effective dietary therapies for some children with epilepsy. 3,4 Small open-label studies suggest efficacy in adults as well. 5 Despite their established success in children with refractory epilepsy, only a few case series from single centers describe the use of KD and MAD in adults with refractory SE (RSE) and SRSE. [6][7][8][9][10][11] Given the severity of illness in patients with SRSE, there is a critical need