CBC and CMP were noted to be within normal limits, with a glucose of 69. Hemoglobin A1c was noted to be 4.8. The patient was diagnosed with seizures, and started on levetiracetam.
The patient discontinued his antiepileptic and had no additional episodes until 11 months later. At this time he had a second episode of altered mental status which resolved after drinking Gatorade. Given his history of resolution with food, workup was undertaken for hypoglycemia including a prolonged fast followed by insulin, C-peptide and proinsulin levels all of which were inappropriately high coupled with a serum glucose of 38. He was diagnosed with an insulinoma.
Discussion: Altered mental status is a common presenting complaint in the emergency department which often results in admission to the hospital. The etiology for altered mental status is broad, and serious conditions must be ruled out prior to discharge. Often times, there are clues in the patient’s history and physical exam that can help guide the workup to reduce length of hospital stay and the number of consultants needed.
Given this patient’s young age, he was thought to be postictal so neurology was consulted. They agreed that this represented a postictal state, hence the patient’s rapid resolution in triage at the emergency department. He was started on an antiepileptic medication and was discharged from the hospital after a normal EEG was obtained.
After the patient had a second episode almost a year later, a thorough history was obtained. It was noted that in both cases, there was resolution of his altered mental status after he had oral intake. It was at this time that a broader differential diagnosis was considered, and an evaluation for hypoglycemia ensued. The patient underwent prolonged fast followed by measurement of his serum insulin, C-peptide and proinsulin levels. All 3 of these values were elevated, despite a serum glucose of 38. The patient was diagnosed with a biochemically confirmed insulinoma and was subsequently referred to the Mayo Clinic for endoscopic ultrasound and definitive intervention.
Conclusions: Patients are often admitted to the hospital for altered mental status, and the underlying etiology can be difficult to elucidate given the broad differential diagnosis. A thorough history and will often lend clues to the diagnosis, and avoid prolonged hospital stays to perform a thorough workup into the numerous potential underlying etiologies.