Changing Management Guidelines in Thyrotoxic Hypokalemic Periodic Paralysis

Thyrotoxic Periodic Paralysis: An Under-Recognized Cause of Paralysis in Young Hispanic Men

BACKGROUND

Patients presenting to the emergency department with paralysis can have a wide differential diagnosis. Thyrotoxic periodic paralysis (TPP) is a rare disorder causing transient flaccid paralysis in the setting of thyrotoxicosis and hypokalemia. It has been reported in Asian male populations predominantly, and the diagnosis is rarely considered in non-Asian populations. Recent research has identified cases in patients with diverse ethnic backgrounds, although epidemiologic data from the United States are very limited.

OBJECTIVE

Our aim was to report our experience with TPP at a tertiary care center in the United States.

METHODS

A retrospective chart review was conducted between January 2006 and February 2022 to identify cases of TPP and determine their demographic and clinical characteristics. Prevalence of TPP was estimated using the institutional hyperthyroidism registry.

RESULTS

Thirty-three patients with TPP were identified. All of the patients were male; median age was 28 years, and 85% were Hispanic. All patients had hypokalemia at presentation and 23% had rebound hyperkalemia after treatment. Prevalence of TPP in our population of patients with hyperthyroidism was approximately 0.5%.

CONCLUSIONS

Young Hispanic men presenting with paralysis should be evaluated for TPP, as the prevalence in this population may be higher than estimated previously. Management of TPP involves treatment of underlying hyperthyroidism and cautious potassium repletion, with an initial dose of no more than 60 mEq/L of potassium chloride to avoid rebound hyperkalemia.

Acute myocarditis presenting as accelerated junctional rhythm in Graves’ disease: A case report

BACKGROUND

Acute myocarditis is an acute myocardium injury that manifests as arrhythmia, dyspnea, and elevated cardiac enzymes. Acute myocarditis is usually caused by a viral infection but can sometimes be caused by autoimmunity. Graves’ disease is an autoimmune disease that is a rare etiology of acute myocarditis. Accelerated junctional rhythm is also a rare manifestation of acute myocarditis in adults.

CASE SUMMARY

A rare case of new-onset Graves’ disease combined with acute myocarditis and thyrotoxic periodic paralysis is reported. The patient was a 25-year-old young man who suddenly became paralyzed and felt palpitations and dyspnea. He was then sent to our emergency department (ED). Upon arrival, electrocardiography revealed an accelerated junctional rhythm and ST-segment depression in all leads, and laboratory findings showed extreme hypokalemia and elevated troponin I, with the troponin I level being 0.32 ng/mL (reference range, 0-0.06 ng/mL). Coronary computer tomography angiography was performed, and there were no abnormal findings in the coronary arteries. Subsequently, the patient was admitted to the ED ward, where further testing revealed Graves’ disease, along with continued elevated cardiac enzyme levels and B-type natriuretic peptide (BNP) levels. The troponin I level was 0.24 ng/mL after admission. All of the echocardiography results were normal: Left atrium 35 mm, left ventricle 48 mm, end-diastolic volume 102 mL, right atrium 39 mm × 47 mm, right ventricle 25 mm, and ejection fraction 60%. Cardiac magnetic resonance was performed on the fifth day of admission, revealing myocardial edema in the lateral wall and intramyocardial and subepicardial late gadolinium enhancement in the lateral apex, anterior lateral, and inferior lateral segments of the ventricle. The patient refused to undergo an endomyocardial biopsy. After 6 d, the patient’s cardiac enzymes, BNP, potassium, and electrocardiography returned to normal. After the patient’s symptoms were relieved, he was discharged from the hospital. During a 6-mo follow-up, the patient was asymptomatic and subjected to thyroid function, liver function, kidney function, troponin I, and electrocardiograph routine tests for medicine adjustments. The hyperthyroid state was controlled.

CONCLUSION

Acute myocarditis is a rare manifestation of Graves’ disease. Accelerated junctional rhythm is also a rare manifestation of acute myocarditis in adults. When the reason for hypokalemia and elevated cardiac enzymes in patients is unknown, cardiologists should consider Graves’ disease and also pay attention to accelerated junctional rhythm.

Thyrotoxic Periodic Paralysis in a Young Hispanic Male With Newly Diagnosed Grave's Disease

Thyrotoxic periodic paralysis (TPP) is a unique cause of hypokalemia from transcellular shift into muscle in the setting of active thyrotoxicosis. It is essential to recognize TPP, given the specific management considerations, which would otherwise easily go unaddressed. TPP can also be clinically indistinguishable from other causes of hypokalemia. In particular, familial periodic paralysis can present similar to TPP. This case illustrates a young Hispanic male who presented with paralysis and was found to be hypokalemic. Patient was also found to have thyromegaly with further testing consistent with Grave's disease, despite no hyperthyroid symptoms. Ultimately, identifying TPP early will allow for swift and appropriate treatment, avoid unnecessary interventions and testing, and reduce cost of care.

Noninvasive ventilator prevents intubation in thyrotoxic hypokalemic periodic paralysis-associated respiratory failure: A case report and literature review

Thyrotoxic periodic paralysis (TPP) is a rare complication of hyperthyroidism, often presents with limb muscle paralysis, hypokalemia with elevated-free T3, T4, and low thyroid-stimulating hormone (TSH). We herein reported an unusual presentation of TPP with acute hypercapnic respiratory failure. A 28-year-old female had complaints of nausea and vomiting. Laboratory investigations showed a serum potassium level of 1.2 mEq/L. Thyroid function test revealed the TSH level of 0.021 μlU/mL and free T4 at 2.01 ng/dL. She suddenly suffered from dyspnea and drowsiness. Acute hypercapnic respiratory failure with CO₂ retention was found. Noninvasive ventilation was used. Rapid correction of hypokalemia and administration of propylthiouracil, propranolol, and 5% Lugol's solution were performed. After the normalization of potassium levels, the patient's respiratory pattern stabilized and noninvasive ventilator (NIV) use was discontinued. Respiratory failure is an unusual but lethal complication of TPP. Rapid correction of hypokalemia and temporarily NIV can successfully avoid endotracheal intubation for respiratory failure.

Thyrotoxic periodic paralysis: A retrospective, observational study from India

Background & objectives:

Thyrotoxic periodic paralysis (TPP) is an endocrine emergency presenting with acute-onset flaccid paralysis in a patient having thyrotoxicosis accompanied by hypokalaemia. This study was conducted to evaluate the clinical profile of patients with TPP presenting to three centres in India.

Methods:

This retrospective, observational study was conducted at three tertiary care Armed Forces medical centres, located at Lucknow, Kolkata and Delhi. The history, clinical features, treatment details and outcomes were evaluated.

Results:

Of the 244 patients with thyrotoxicosis, 15 were diagnosed with TPP and included in the study. These 15 patients (14 male and 1 female) had 32 episodes of TPP which were analyzed. The mean age was 30.2±6.2 yr (range: 21-39), and overt thyrotoxicosis was seen in all patients except one who had subclinical hyperthyroidism. Graves’ disease was the most common cause of thyrotoxicosis (13/15) and the remaining two patients had subacute thyroiditis and gestational thyrotoxicosis. Hypokalaemia (serum potassium <3.5 mmol/l) was seen in 12 patients, and the mean serum potassium was 3.2±0.9 mmol/l (range: 2.1-4.9). All patients had flaccid weakness, predominantly involving the lower limb with no bulbar, respiratory or cranial nerve involvement. The average duration of paralysis was 10.6±5.7 h (range: 3-28 h).

Interpretation & conclusions:

Our study demonstrated an early age of presentation and presence of clinical and biochemical thyrotoxicosis in majority of patients with TPP. Hypokalaemia may not always be evident in patients with TPP.

Thyrotoxic Muscle Paralysis as a Rare Cause of Reversible Muscle Weakness: A Case Report

Thyrotoxic periodic paralysis is a clinical condition characterized by muscle weakness in patients with underlying hyperthyroidism. It is usually more commonly seen in patients of Asian origin and has a predisposition for the male population (unlike other thyroid disorders which commonly affect the female population). Findings are more overt in patients who have subclinical hyperthyroidism and there is a risk of them remaining untreated. The symptoms can range from mild muscle weakness to total paralysis. The muscles affected predominantly are the proximal and lower extremities group of muscles. Thyrotoxic muscle paralysis can be precipitated by hyperinsulinemic states such as after heavy meals, physical exertion, obesity, stress, and certain medications like high-dose steroids, antiretrovirals, and interferon therapy. The acute intervention usually revolves around the replenishment of patient's potassium stores followed by maintenance therapy with anti-thyroid medications. We present a case of a Chinese adolescent who presented to us with lower muscle weakness and underlying subclinical hyperthyroidism. It's important for clinicians to be familiar with this disease entity and include it in their differentials whenever a patient with muscle weakness presents. The treatment is simple and can result in rapid improvement of symptoms and should be initiated quickly.

Impact of first-line treatment choice on long-term outcomes of hyperthyroid Graves' disease patients with thyrotoxic periodic paralysis

Background

Thyrotoxic periodic paralysis (TPP) is a unique manifestation of Graves’ disease. While it is uncommon in Asian, it is extremely rare in Caucasian patients (0.1–0.2%). Previous studies suggested that TPP indicate more severity of Graves’ disease and definitive treatments should be used to prevent relapses.

Aim

To describe clinical features and impact of first-line treatment on long-term outcomes of TPP patients.

Method

A retrospective cohort study over 35 years (1985–2019) of TPP from Graves’ disease patients was conducted. All cases were analyzed and their clinical courses were compared between those who received anti-thyroid drugs (ATD) versus radioactive iodine (RAI) as a primary treatment. None of them underwent surgery.

Results

A total of 2964 hyperthyroid Graves’ disease patients were treated and followed-up at least 3 months over the study period. TPP was identified in 63 cases (2.1%) of all patients. There were 60 males and only 3 females with age at presentation of 35.0 ± 8.2 years. TPP was the first presentation of hyperthyroid Graves’ disease in 82.5% of them. During the acute attack of TPP, all patients presented with bilateral lower limb flaccid weaknesses with median serum potassium of 2.1 mmol/L. No fatal TPP cases were found. RAI was selected as primary treatment in 27 patients (42.9%). Nearly all RAI-treated patients rendered hypothyroidism with the median RAI dose at 15 mCi. No patients who were in remission after RAI treatment developed recurrent attack of TPP. In the remaining 36 ATD-treated patients with mean follow-up time at 9.1 years, relapse was found in 10 patients (27.8%) after the drug discontinuation and 6 patients suffered recurrent TPP. Only 8 ATD-treated TPP patients (22.2%) went into remission.

Conclusions

TPP is a rare complication of hyperthyroid Graves’ disease. Definitive treatment with RAI or thyroidectomy should be employed to prevent relapse and further attacks of TPP.

[Hormones and Mobility]

Hormones and Mobility Abstract. Endocrine disorders affect mobility in many and sometimes characteristic ways such as Cushing's syndrome or hyperparathyroidism, which have direct, hormone-mediated effects on skeletal and muscular tissues. On the other hand, the endocrine system plays an important role in the development of (osteo)sarcopenia, the meaning of which is increasingly recognized in the prognosis of various diseases. Conversely, lack of physical activity is crucial in the development of metabolic diseases, which are associated with serious individual and socio-economic consequences.