Abstract
A 68 year old man travelling from the UK presented with 1 hour of confusion and horizontal diplopia. Symptoms had resolved by presentation. Background was remarkable for prior polio, and he had no history of migraines. His medications included semaglutide injections for weight loss. He had experienced 4 episodes of horizontal diplopia over the past 2 months, all sudden onset, short-lived, and spontaneously resolving, with no other other associated symptoms.
Examination on admission was unremarkable barring mild residual weakness from polio. CT and MRI were normal.
The patient had multiple asymptomatic episodes of hypoglycaemia (often with BSL ≤2). Bloods taken during hypoglycaemia revealed elevated insulin (25) and C-peptide levels (1.98), and CT abdomen revealed a small pancreatic tumour. An insulinoma was diagnosed.
Semaglutide was stopped, and the patient was instructed to eat frequent small meals, and carry sugary snacks to eat in case he developed symptoms of hypoglycaemia. He preferred to have ongoing work-up for insulinoma resection in the UK, and he was discharged.
Insulinomas typically manifests with neuroglycopaenic symptoms (confusion, visual blurring, unusual behaviour) and/or sympathoadrenal symptoms (including palpitations, diaphoresis, tremor). Recurrent hypoglycaemia can cause blunting of the sympathoadrenal response, leading to lack of hypoglycaemia awareness. Hypoglycaemia can also cause focal neurological deficits and can present as a stroke mimics. Up to 20% of insulinomas are initially misdiagnosed as other neurological or psychiatric conditions. Insulinomas are typically benign tumours. Surgical resection is the definitive treatment, which leads to resolution of hypoglycaemic episodes in approximately 90% of cases.
