Thyrotoxic periodic paralysis in a caucasian man
E-L Lim, IM Ibrahim & R Quinton
Clinical case: A 37 year-old Caucasian man was admitted with sudden onset lower limb weakness following a carbohydrate-heavy meal the night before. Pulse was 110/min, sinus rhythm, BP 167/92 mmHg. There was generalised muscle weakness, particularly in his legs, with hyporeflexia and hypotonia. There was no sensory deficit and plantar responses were downgoing. Serum K+ was 2.4 mmol/L, associated with typical ECG anomalies, and was corrected with 40 mmol intravenous KCl followed by oral supplements. He gave a 2-year history of intermittent palpitations, heat intolerance, tremors and increased bowel frequency, but no weight loss or increased appetite. Diffuse thyroid enlargement was noted and thyrotoxicosis was confirmed biochemically (t-T4 198 pmol/L, TSH <0.05 mU/L, TPO antibodies elevated at 489 U/L).