19th February 2025

A 58-year-old gentleman presents to the emergency department after a witnessed tonic clonic seizure

A 58-year-old gentleman presents to the emergency department after a witnessed tonic clonic seizure. On questioning his spouse, you learn that he has a past history of type 2 diabetes mellitus, hypertension and small cell lung cancer. His wife tells you that he started treatment for his cancer one week earlier.

On assessment, he is confused but awake, with an otherwise normal neurological examination.

Investigations are as follows: random glucose 9.8 mmol/L, pH 7.35 (7.35 – 7.45), ketones 0.1 mmol/L (<0.6 mmol/L), Na 146 mmol/L (133-146 mmol/L), K 6.2 mmol/L (3.5-5.3 mmol/L), Creatinine 130 µmol/L (45-104 µmol/L), Urea 5.6 mmol (2.5-7.8 mmol/L), PO4 1.9 mmol/L (0.80-1.50 mmol/L), Ca 1.45 mmol/L (2.20-2.60 mmol/L).

What is the most likely diagnosis?

Select the SINGLE most appropriate option from the list below. Select ONE option only.