Hypokalaemic Paralysis - A double trouble from concurrent Thyrotoxicosis and Gitelman syndrome: A report of two cases

Background
Hypokalaemic paralysis is a rare group of disorders with concomitant muscle weakness and hypokalaemia. Thyrotoxicosis is a recognized and a common cause for hypokalaemic paralysis among Asians, in which intracellular shift of potassium is enhanced. Gitelman syndrome, an autosomal recessive renal salt loosing condition is characterized by hypokalaemia, hypocalciuria and hypomagnesaemia. Concurrence of these two conditions is very rarely reported.

Case Presentation
We report two genetically unrelated Sri Lankan patients who presented with concurrent thyrotoxicosis and Gitelman syndrome. Both of them presented with symptomatic hypokalaemia and detected to have thyrotoxicosis. One had Grave’s disease, while the other patient had toxic multinodular goiter. They were initially managed symptomatically for thyrotoxic hypokalaemic paralysis. Despite rendering euthyroidism with medical management, they persisted to have symtomatic hypokalaemia. On evaluation for a second pathology, we detected them to have Gitelman syndrome, which is a rare concurrence.

Conclusion
Elevated thyroid hormone levels can precipitate a paralytic episode in a patient with subclinical chronic hypokalaemia due to an additional underlying disease. Gitelman syndrome is such a disease which should be considered and actively looked for in a patient with persistent hypokalaemia following rendering euthyroidism.