Thyrotoxic periodic paralysis: an unusual presentation of weakness

Abstract

Thyrotoxic periodic paralysis is a rare endocrine disorder seen predominantly in men of Asian origin. The case is reported of a patient who presented to the accident and emergency department with sudden onset of weakness of his lower limbs. Hypokalaemia was identified and treated with resolution of symptoms. Additional tests identified the patient as being thyrotoxic. He was treated with oral antithyroid drugs. It is important to consider the diagnosis of thyrotoxic periodic paralysis in patients presenting with acute onset of weakness. The report discusses the epidemiology, presentation, treatment, and complications of this condition.

Thyrotoxicosis presenting as hypokalaemic paralysis and hyperlactataemia in an oriental man

“…Hypophosphataemia may also occur due to a similar mechanism of transcellular shift. 2,3,5 Other interesting biochemical ¢ndings in our case were hyperlacatataemia (blood lactate 5.6 mmol/L) and a mixed respiratory alkalosis and a high anion gap metabolic acidosis (see Table 1). The respiratory alkalosis could be explained by hyperventilation as the patient was anxious and frightened from the sudden onset of paralysis.…”

Stroke Mimic: A Case of Unilateral Thyrotoxic Hypokalemic Periodic Paralysis

“…THPP has a 0.1-0.2% prevalence in the United States, typically presenting with transient symmetric skeletal muscle paralysis, which usually affects the lower extremities disproportionately to the upper extremities. 3,4,5 It occurs more frequently in Asian populations and typically presents in Asian men ages 20 to 40. 3 Males are more susceptible than females, with reported ratios ranging from 17:1 to 70:1.…”

“…Hyperthyroidism upregulates the Na + /K + pump expression on skeletal muscle in addition to increasing the pump activity. 1,2,4 As a result, the cell sequesters K + intracellularly, leading to the common pathway for many acquired paralysis syndromes: hypokalemia. 6 Thyrotoxicosis alone, however, does not result in episodic paralysis, nor do free T4 levels correlate to symptoms.…”

Thyrotoxic Hypokalemic Periodic Paralysis: A Case Series from Trinidad, West Indies

“…The treatment of TPP requires urgent correction of potassium levels. Paul et al demonstrated that potassium replacement should be tailored according to patients' symptoms and potassium levels upon presentation (32). For potassium concentrations above 2.5 mmol/L and patients presenting with mild weakness, treatment should be initiated with 80 mmol/ 24 hours of oral potassium.…”

“…The total potassium replacement required for the correction of hypokalaemia in TPP is relatively small compared to that seen in other causes of hypokalaemia where a potassium deficit exists. Continuous ECG monitoring to check for arrhythmias, peak flows and serial arterial blood gases to monitor respiratory function should be performed (32).…”