Thyrotoxic Periodic Paralysis: An Underdiagnosed and Under-recognized Condition.

Anuhya Kommalapati,Sri Harsha Tella

doi:10.7759/cureus.342

Abstract

Thyrotoxic hypokalemic periodic paralysis (TPP) is a condition characterized by the triad of acute hypokalemia without total body potassium deficit, episodic muscle paralysis, and thyrotoxicosis.We describe two cases of thyrotoxic periodic paralysis who presented to our hospital with potassium values of 1.3 MeQ/l and 1.2 MeQ/l, respectively. Surprisingly, the two patients had no documented past medical history. Based on the clinical features of high heart rate, palpitations (seen in both the patients), and exophthalmos (seen in one patient), thyrotoxic periodic paralysis was suspected. A thorough laboratory workup confirmed the diagnosis of thyrotoxicosis. Beta blockers were initiated promptly, along with intravenous potassium chloride, and the patients eventually improved symptomatically. These patients were eventually diagnosed with Graves’ disease and were placed on methimazole, which prevented further attacks.Thyroid periodic paralysis (TPP) is a rare clinical manifestation of hyperthyroidism. Patients present with sudden onset paralysis associated with severe hypokalemia. The presence of paralysis and hypokalemia in a patient who has a history of hyperthyroidism should prompt the physician about thyrotoxic periodic paralysis. A high index of suspicion, prompt diagnosis, and management of the condition can prevent severe complications, such as cardiac arrhythmias.

Highlights

Thyrotoxic hypokalemic periodic paralysis (TPP) is a condition characterized by the triad of acute hypokalemia without total body potassium deficit, episodic muscle paralysis, and thyrotoxicosis
Thyrotoxic periodic paralysis (TPP) is a rare life-threatening complication of untreated or unrecognized hyperthyroidism characterized by episodes of muscle weakness and hypokalemia
It is postulated that male hormones increase Na+/K+-ATPase activity, and that this explains why males are at a higher risk of TPP despite thyroid disease being more common in females [6]

Summary

Introduction

Thyrotoxic hypokalemic periodic paralysis (TPP) is a condition characterized by the triad of acute hypokalemia without total body potassium deficit, episodic muscle paralysis, and thyrotoxicosis. With the increased thyroid hormone levels in the setting of increased radioiodine uptake, the patient was eventually diagnosed with Graves' disease. He was discharged on methimazole and propranolol with a scheduled outpatient follow-up. His thyroid function tests were as follows: free T4 - 6.57 ng /ml (0.601.60), TSH - 0.05 IU/ml (0.34-5.60), and free T3 - 8.78 pg/ml (2.5-3.9). As the patient was started on methimazole, 10 mg thrice a day, we did not get a radioiodine scan He was followed as an outpatient regularly. The patient became euthyroid and no further episodes of paralysis were noted in the 18 months follow-up period

Discussion

Conclusions

Disclosures

Kung AW: Clinical review

Findings

Ober KP

12. Wong P