Hypokalemic thyrotoxic periodic paralysis: clinical characteristics and predictors of recurrent paralytic attacks

Hyperandrogenism and Hypokalemic Thyrotoxic Periodic Paralysis in a North American Adolescent Girl

We present a unique case of hypokalemic thyrotoxic periodic paralysis (TPP) in an adolescent girl in North America. TPP is a rare but dangerous complication seen in thyrotoxic patients characterized by hypokalemia and acute proximal symmetric lower-extremity weakness. It is an especially rare phenomenon in pediatrics, with roughly 20 case reports described in adolescents worldwide; the majority are male. Our patient is a 14-year-old Asian girl with biochemical hyperandrogenism and known Graves disease who presented with an acute episode of lower-extremity weakness after eating a carbohydrate-rich meal. Laboratory workup revealed hypokalemia, hypomagnesemia, an undetectable thyrotropin, and hyperthyroxinemia. Electrolyte derangements responded well to supplementation, and the muscle weakness resolved with electrolyte normalization. Following improvement in thyroid function, the patient underwent thyroidectomy for definitive management of Graves disease. As TPP is potentially exacerbated by higher androgen and insulin levels, we suspect that with increasing rates of obesity and polycystic ovary syndrome, the incidence of TPP among adolescents may increase. It is therefore critically important that there is awareness and recognition of this serious diagnosis among all health care providers.

Thyrotoxic periodic paralysis presenting with quadriparesis and hyperreflexia

Thyrotoxic periodic paralysis (TPP) is a rare complication of hyperthyroidism that manifests as painless flaccid paralysis. An East Asian man in his late 20s presented to the emergency department with an acute onset of quadriparesis associated with hypertonia and hyperreflexia. His initial symptoms and signs suggested involvement of the brain and spinal cord; however, MRI of the neuroaxis was normal. His serum potassium concentration was low, and thyroid test results were consistent with hyperthyroidism. The patient was diagnosed with TPP associated with Graves' disease and was treated with potassium supplementation, propranolol and methimazole. Motor strength improved to his baseline level of power; bulk was normal, and tone was increased. Although flaccid paralysis is a typical presentation of TPP, brisk reflexes and muscle spasticity cannot rule out this condition. This case highlights the importance of considering TPP as a possible diagnosis in patients presenting with acute quadriparesis.

Thyrotoxic periodic paralysis as the first presentation of Graves' disease: A case report

Thyrotoxic periodic paralysis (TPP) is a rare disease seen predominantly in men of Asian origin. It should be considered in the differential diagnosis of patients with acute onset of weakness, and it is reversible after the correction of serum potassium. TPP can rarely be the initial presentation of Graves' disease.

An Interesting Case of Weakness and Atrial Tachycardia in the Emergency Department: Thinking Beyond Hearts and Minds

Thyrotoxic periodic paralysis is a rare but life-threatening presentation of hyperthyroidism that manifests with sudden, painless episodes of muscle weakness due to hypokalemia. We present the case of a middle-aged Middle Eastern female who attended our Emergency Department with sudden onset weakness to the lower limbs, resulting in her inability to walk. She had a power of 1/5 in the lower limbs, and subsequent investigations showed a low potassium level, and primary hyperthyroidism secondary to Grave's disease was diagnosed. A 12-lead electrocardiogram showed atrial flutter with a variable block, along with U waves. The patient reverted to sinus rhythm following administration of potassium replacement and was also treated with Propanalol and Carbimazole. The patient made a full neurological recovery.  Emergency physicians and all frontline healthcare workers should be aware that electrolyte problems can cause paralysis. Furthermore, hypokalemic periodic paralysis can be caused by an undiagnosed thyrotoxic state. Be aware that if left untreated, hypokalemia can cause serious atrial and ventricular arrhythmias. Achieving a euthyroid state and blunting hyperadrenergic stimulation, in addition to replacing potassium, all help to fully reverse muscle weakness.

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.

Case report: SCN4A p.R1135H gene variant in combination with thyrotoxicosis causing hypokalemic periodic paralysis

Hypokalemic periodic paralysis (HPP) is a heterogeneous group of diseases characterized by intermittent episodes of delayed paralysis of skeletal muscle with episodes of hypokalemia, caused by variants in CACNA1S or SCN4A genes, or secondary to thyrotoxicosis, Sjogren syndrome, primary aldosteronism, etc. HPP may be the only presentation in Andersen-Tawil syndrome in which the majority of cases are caused by pathogenic variants in the KCNJ2 gene. We present a case of a 29-year-old male with hypokalemic periodic paralysis. The patient began to experience recurrent weakness of the extremities at the age of 26, which was effectively treated with potassium supplementation. He had recently developed dry mouth, palpitations, weight loss, and even dyspnea, with a serum potassium level as low as 1.59 mmol/L. The results of auxiliary examinations showed Graves' disease, and genetic testing indicated a missense variant, NM_000334.4 (SCN4A):c.3404G>A (p.R1135H). He did not experience periodic paralysis during follow-up after lifestyle guidance and treatment of thyrotoxicosis with radioactive iodine. It is a rare case of SCN4A p.R1135H gene variant combined with hyperthyroidism resulting in HPP with respiratory muscle paralysis to raise awareness of the disease and avoid misdiagnosis and missed diagnosis.

Management of hypokalemia in patients with thyrotoxicosis periodic paralysis in Soetomo general hospital: A case report

Introduction

The prevalence of Graves' disease varies widely between 21 and 80% of all cases of hyperthyroidism. Research conducted in 2018 at the Dr. Soetomo Regional General Hospital Surabaya found Graves' disease in as many as 66.7% of all cases of hyperthyroidism. Thyrotoxicosis Periodic Paralysis (TPP) is a disorder characterized by reversible muscle weakness and paralysis, accompanied by hypokalemia, which usually accompanies hyperthyroidism, mostly caused by Graves' disease. Management of severe hypokalemia in TPP is challenging.

Case illustration

male, 29 years patient complained that both lower legs felt weak in the last 6 hours before coming to the hospital emergency department. The patient was diagnosed with hyperthyroidism in 2018. A fine tremor was found, and the patient was admitted to the hospital for 4 days and routinely controlled at the endocrine polyclinic.

Clinical discussion

The underlying disease or causative etiology of thyrotoxicosis must be determined before treatment is conducted. The main concern when performing potassium replacement therapy is the occurrence of rebound hyperkalemia because this hypokalemia condition is caused not by total potassium depletion.

Conclusion

The principles of management for thyrotoxicosis periodic paralysis are proper diagnosis, exclusion of other causes of paralysis, and other causes of hypokalemia, slow and gradual correction of hypokalemia, and close and careful clinical monitoring, ECG, and laboratory.

Case report: Hyperthyroid hypokalemic periodic paralysis

Introduction and importance

HHPP is a rare type of hypokalemic PP that can occur when there is hyperthyroidism.Thyrotoxic periodic paralysis is due to increased influx of potassium into skeletal muscle cells which leads to profound hypokalemia and paralysis. Insulin and Epinephrine are also responsible for stimulating the Na–K-ATPase pumps which are over expressed during hyperthyroid state. Laboratory hypokalemia in the background of hyperthyroidism with sudden symmetric paralysis point toward the diagnosis.

Case

We present a case of 25 year old male with limb weakness for 3hours following heavy dinner.He felt weakness after waking up in the morning where he could not move his both lower limbs. He also had difficulty moving upper limbs.

Clinical findings and investigations

Examination revealed proximal muscle weakness with power of 2/5, decreased muscle tone, diminished deep tendon reflexes in all four limbs and equivocal plantar reflex bilaterally. Investigation sent were Total Leukocyte count, Hemoglobin, Renal function test, Liver Function test,Thyroid function test, Vitamin B12, Serology, ACTH, Serum calcium, Serum phosphate, Serum magnesium, Urine R/ME and Stool R/ME.

Intervention and outcome

Patient is treated with 10mEq/L/hr infusion of potassium chloride, methimazole and beta-blockers. He is stable and is in regular followup in medicine OPD.

Relevance and impact

Early diagnosis of HHPP is very essential to prevent fatal complications (cardiac and respiratory).

It can be treated by timely potassium supplementation, methimazole and beta-blockers.

Clinicians must be concerned about Hyperkalemia while supplementing Potassium in bed side.

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HHPP is a rare life-threatening complication of hyperthyroidism which is characterized by episodes of acute muscle weakness due to hypokalemia.

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Periodic paralysis (PP) is a muscle disease, characterized by episodes of painless muscle weakness. These episodes can be triggered by strenuous exercise, fasting, or consuming high-carbohydrate foods.

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Treatment cand be done by potassium supplementation until normalized serum potassium level. Patient must be kept in cardiac monitoring and serum potassium monitoring.

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Hyperthyroidism can be treated with methimazole. Patient must be kept under regular follow up in endocrinology department.

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Relapses can be prevented by treatment with radioactive iodine or surgery. Beta-blocking drugs have also been proven to reduce the frequency and severity of episodes.

Recurrent thyrotoxic periodic paralysis with normokalemia in a 36-year-old man: A case report

Among patients with thyrotoxicosis and proximal muscle weakness, some patients with TPP may present with apparent normokalemia in whom a careful administration of potassium may lead to rapid reversal of muscle weakness.

Artificial Intelligence-Assisted Electrocardiography for Early Diagnosis of Thyrotoxic Periodic Paralysis

Context

Thyrotoxic periodic paralysis (TPP) characterized by acute weakness, hypokalemia, and hyperthyroidism is a medical emergency with a great challenge in early diagnosis since most TPP patients do not have overt symptoms.

Objective

This work aims to assess artificial intelligence (AI)-assisted electrocardiography (ECG) combined with routine laboratory data in the early diagnosis of TPP.

Methods

A deep learning model (DLM) based on ECG12Net, an 82-layer convolutional neural network, was constructed to detect hypokalemia and hyperthyroidism. The development cohort consisted of 39 ECGs from patients with TPP and 502 ECGs of hypokalemic controls; the validation cohort consisted of 11 ECGs of TPP patients and 36 ECGs of non-TPP individuals with weakness. The AI-ECG–based TPP diagnostic process was then consecutively evaluated in 22 male patients with TTP-like features.

Results

In the validation cohort, the DLM-based ECG system detected all cases of hypokalemia in TPP patients with a mean absolute error of 0.26 mEq/L and diagnosed TPP with an area under curve (AUC) of approximately 80%, surpassing the best standard ECG parameter (AUC = 0.7285 for the QR interval). Combining the AI predictions with the estimated glomerular filtration rate and serum chloride boosted the diagnostic accuracy of the algorithm to AUC 0.986. In the prospective study, the integrated AI and routine laboratory diagnostic system had a PPV of 100% and F-measure of 87.5%.

Conclusion

An AI-ECG system reliably identifies hypokalemia in patients with paralysis, and integration with routine blood chemistries provides valuable decision support for the early diagnosis of TPP.

Thyrotoxic Periodic Paralysis Causing Back Pain and Leg Weakness: An Unusual Presentation of Hyperthyroidism

Thyrotoxic periodic paralysis (TPP) is a rare muscular disorder, characterized by muscle weakness and hypokalemia triggered by thyrotoxicosis. In Asian populations, 2% of patients with thyrotoxicosis are affected, compared to only 0.1-0.2% of non-Asians. The vast majority of patients are male. Muscle weakness ranges in severity from very mild to life-threatening, due to respiratory compromise. We present a case of a previously healthy 39-year-old Hispanic male who presented with sudden quadriparesis and quickly recovered after being treated for hypokalemia and thyrotoxicosis. TPP, although unusual, is important to recognize as it is a potentially fatal condition that requires close monitoring and is readily reversible with appropriate therapy. Any cause of thyroid hormone excess can cause TPP, with Graves' disease being the most common etiology. Acute treatment includes potassium repletion, while long-term management focuses on determining and treating the cause of thyrotoxicosis, since maintaining a euthyroid state will prevent further episodes of TPP.

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.

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.

Thyrotoxic Periodic Paralysis and Complicated Thyrotoxicosis, Two Presentations of Hyperthyroidism with Notable Differences in their Clinical Manifestations: An Experience from a Tertiary Care Hospital in the United States

OBJECTIVE

Thyrotoxic periodic paralysis (TPP) is a muscular disorder characterized by sudden episodes of muscle weakness and hypokalemia in the setting of thyrotoxicosis. We aimed to report our experience with TPP in West Texas and compare its clinical presentation to that of patients admitted for complicated thyrotoxicosis.

METHODS

Retrospective review of records of adult patients with admission diagnosis of hyperthyroidism, thyrotoxicosis, and/or discharge diagnosis of periodic paralysis seen at our institution in a 6-year period.

RESULTS

Patients admitted for complicated thyrotoxicosis were more commonly females of a mean age of 44 years. Patients with TPP were more commonly Hispanic males of a mean age of 27 years. Despite no significantly different thyroid hormone levels, patients with TPP presented with less-severe signs and symptoms of hyperthyroidism, as reflected by lower Burch-Wartofsky score on admission (19 vs. 35; P<.001) and lower occurrence of atrial fibrillation in the TPP group (0% vs. 36%; P<.001). Finally, 89% of TPP patients presented with corrected QT (QTc) prolongation, whereas only 19% of thyrotoxic patient presented with a prolonged QTc.

CONCLUSION

Hispanic patients with TTP seems to have relative resistance to the actions of thyroid hormones and commonly present with QTc prolongation, a risk factor for cardiac arrhythmias.

ABBREVIATIONS

BWS = Burch-Wartofsky point scale; EKG = electrocardiogram; FT3 = free triiodothyronine; FT4 = free thyroxine; ICD = International Classification of Diseases; QTc = corrected QT; TPP = thyrotoxic periodic paralysis.

Thyrotoxic Periodic Paralysis-A Misleading Challenge in the Emergency Department

Despite its' life-threatening potential due to cardiac severe dysrhythmia in the context of severe hypokalemia, thyrotoxic periodic paralysis (TPP) often goes unrecognized. Although classically confined to young Asian men, it can occur irrespective of age, sex, and race. We report a short series of three cases of TPP as first presentation of Graves' disease in a young Caucasian male and in two Caucasian elderly and middle-aged women, respectively. The first patient developed malignant ventricular arrhythmias due to severe hypokalemia and was defibrillated, with recovery after prompt potassium correction and administration of antithyroid agents and propranolol. The other two cases developed persistent hypokalemia despite adequate potassium chloride (KCl) repletion, with slow recovery of motor deficit and serum potassium normalization up to day 5. In the first case, long-term euthyroid state was achieved via total thyroidectomy due to the presence of a suspicious nodule that proved to be malignant. In the other two cases, medical treatment was the choice of therapy for thyrotoxicosis. None experienced recurrent TPP. Thyroid hormone evaluation is mandatory in the presence of hypokalemic paralysis, even in the absence of clinical signs of thyrotoxicosis. If TPP is confirmed, initial therapy should comprise antithyroid drugs and propranolol, besides hypokalemia correction.

Thyrotoxic periodic paralysis: case report and review of the literature

Introduction

Thyrotoxic periodic paralysis (TPP) is a rare and potentially lethal complication of hyperthyroidism. It is characterized by sudden onset paralysis associated with hypokalemia. Management includes prompt normalization of potassium, which results in resolution of the paralysis. Definitive treatment of hyperthyroidism resolves TPP completely.

Case presentation

A 23-year-old African American male patient presented to the emergency room at the University of Mississippi Medical Center, USA in November 2016 with sudden onset quadriplegia. He also endorsed a history of weight loss, palpitations, heat intolerance and tremors. The patient reported similar episodes of quadriplegia in the past, which were associated with hypokalemia and resolved with normalization of potassium levels. Physical examination was significant for exophthalmos, smooth goiter with bruit consistent with the diagnosis of Graves’ disease. Laboratory assessment showed severe hypokalemia, hypomagnesemia, suppressed thyroid stimulating hormone (TSH) and high free thyroxine (T4). Urine potassium creatinine ratio was less than one, indicating transcellular shift as the cause of hypokalemia. After normalization of potassium and magnesium, the paralysis resolved in 12 hours. He was started on methimazole. On follow up, the patient was clinically and biochemically euthyroid with no further episodes of paralysis.

Take-away lesson

TPP is a rare and reversible cause of paralysis. Physicians need to be aware of the diagnostic and treatment modalities as delayed recognition in treatment could result in potential harm or unnecessary interventions.

Changing Management Guidelines in Thyrotoxic Hypokalemic Periodic Paralysis

BACKGROUND

Periodic paralysis is a rare complication of hyperthyroidism. Patients of East Asian descent are most commonly affected. Presentation is characterized by recurrent episodes of painless, abrupt-onset weakness, with laboratory evaluation characterized by profound hypokalemia. Underlying hyperthyroidism may not be clinically evident, but differentiation from the familial variant is critical due to differing treatment pathways.

CASE REPORT

We describe the presentation of a 22-year-old man with recurrent relapsing-remitting weakness with undiagnosed hyperthyroidism. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: In patients with acute-onset paralysis with significant hypokalemia, or relapsing-remitting symptoms, hyperthyroidism should be suspected. Obese patients are at an especially increased risk due to underlying insulin resistance, which enhances basal sodium-potassium ATPase function. Hypokalemia is functional in nature. Nonselective β-blockers (such as propranolol) should be considered first line, as they simultaneously decrease ATPase activity, limit insulin secretion, and address the underlying disorder. Administration of > 50 mEq of exogenous potassium places patients at risk of dysrhythmias from rebound hyperkalemia.

Periodic Paralysis and Encephalopathy as Initial Manifestations of Graves' Disease: Case Report and Review of the Literature

BACKGROUND

Thyrotoxic periodic paralysis (TPP) is an uncommon complication of Graves' disease, characterized by the triad of acute hypokalemia without total body potassium deficit, episodic muscle paralysis, and thyrotoxicosis. Graves' encephalopathy is an extremely rare form of encephalopathy associated with autoimmune thyroid disease (EAATD), characterized by neuropsychiatric symptoms, increased antithyroid antibodies and cerebrospinal fluid protein concentration, nonspecific electroencephalogram abnormalities, and cortico-responsiveness. Coexistence of both these complications in the same patient has not been reported before.

CASE REPORT

We herein present a 48-year-old white male patient with TPP and encephalopathy as initial presentations of Graves' disease. Flaccid tetraparesis was reversed a few hours after potassium level correction and the patient did not suffer any relapse with the successful pharmaceutical management of the thyroid function. One month later, the patient presented with dizziness and behavioral symptoms, such as inappropriate laughter and anger. Brain magnetic resonance imaging revealed meningeal enhancement and cerebrospinal fluid analysis showed a mild protein increase, with a blood-brain barrier disruption. With the suspicion of EAATD, the patient was treated with high doses of corticosteroids and improved dramatically.

CONCLUSIONS

To our knowledge this is the first reported coexistence of potentially treatable TPP and EAATD as initial neurological manifestations of Graves' disease, thereby underscoring the necessity of suspicion of possible underlying Graves' disease in patients with acute paralysis and encephalopathy of unclear origin.

Thyrotoxic periodic paralysis: a case study and review of the literature

Acute hypokalemic paralysis is a rare cause of acute weakness. Morbidity and mortality associated with unrecognized disease can occur and include respiratory failure and possibly death. Common causes of hypokalemic paralysis include thyrotoxic periodic paralysis (TPP) which is a disorder most frequently seen in Asian males. TPP is characterized by sudden onset of hypokalemia and paralysis that primarily affects the lower extremities. Treatment of TPP includes replacing potassium rapidly, using nonselective beta-blockade and correcting the underlying hyperthyroidism as soon as possible. TPP is curable once euthyroid state is achieved. It is vital for physicians to be able to differentiate TPP from familial hypokalemic periodic paralysis, a more common cause of periodic paralysis in Caucasians and western countries. We describe a 19-year-old Caucasian man who presented with acute onset lower extremity paralysis secondary to acute hypokalemia and was found to have new onset Graves’ disease.

Abbreviations: TPP: Thyrotoxic periodic paralysis

Thyrotoxic Periodic Paralysis: An Underdiagnosed and Under-recognized Condition

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.

A case report of sudden-onset upper and lower extremity weakness

Thyrotoxic hypokalemic periodic paralysis is characterized by acute attacks of muscle paralysis, hypokalemia, and thyrotoxicosis. It is a medical emergency, as fatal and life-threatening ventricular arrhythmia associated with hypokalemia has been reported. A 24-year-old man presented with severe lower extremity weakness, which progressed to his trunk and arms. He denied any associated symptoms and had no history of a similar episode or predisposing condition. The physical examination was significant for bilateral extremity weakness, more severe in the lower as compared to the upper extremities. The rest of the neurologic exam was normal. A small, smooth, nontender goiter was palpated. Laboratory data was significant for a potassium level of 2.0 mEq/L. Final lab data revealed a thyroid panel consistent with hyperthyroidism. Once the patient's potassium level normalized after repletion, he recovered his strength and was able to walk again. He was diagnosed with thyrotoxic hypokalemic periodic paralysis, a potentially lethal complication of hyperthyroidism. Because it is reversible with treatment of hyperthyroidism, it is imperative that this condition be considered, recognized and managed appropriately.

Severe exacerbation of Andersen-Tawil syndrome secondary to thyrotoxicosis

Thyrotoxic periodic paralysis (TPP) is a rare complication of hyperthyroidism characterized by episodes of weakness. Although TPP has been described in patients all over the world, it is especially frequent in Asiatic patients. Recently, two genomewide association studies have found a susceptibility locus on chromosome 17q24.3 near the KCNJ2 gene, which is responsible for another cause of periodic paralysis, the Andersen-Tawil syndrome (ATS). We report the first patient diagnosed with ATS with a de novo c.G899C mutation in the KCNJ2 gene in 2010 who developed an autoimmune hyperthyroidism and TPP in 2013. At the time of the ATS diagnosis other causes of periodic paralysis, including thyroid dysfunction, were ruled out. The condition of the patient, who had mild episodes of proximal weakness at follow-up, deteriorated dramatically in 2013, presenting continuous episodes of severe generalized weakness associated with low levels of potassium requiring frequent admissions to the hospital. After a few months, he also presented signs of hyperthyroidism, and a diagnosis of Grave's disease was made. In our opinion, this case clearly demonstrates that a dysfunction of the Kir2.1 potassium channel encoded by the KCNJ2 gene is a risk factor to develop TPP, and can be a useful tool to identify patients at risk in daily clinics.

Thyrotoxic periodic paralysis: clinical challenges

Thyrotoxic periodic paralysis (TPP), a disorder most commonly seen in Asian men, is characterized by abrupt onset of hypokalemia and paralysis. The condition primarily affects the lower extremities and is secondary to thyrotoxicosis. The underlying hyperthyroidism is often subtle causing difficulty in early diagnosis. Factors like high-carbohydrate meal exercise, steroid, and stress can precipitate an attack of TPP. Evidence is building up showing role of genetic mutations in Kir2.6 channel in the pathogenesis of TPP. Loss of function of Kir2.6 together with increased activity of Na(+)/K(+) ATPase may trigger a positive feed-forward cycle of hypokalemia. Biochemical hyperthyroidism with normal urinary potassium excretion and ECG changes are characteristic of TPP. Treatment with low-dose potassium supplements and nonselective beta-blockers should be initiated upon diagnosis, and the serum potassium level should be frequently monitored to prevent rebound hyperkalemia.

Thyroid disease and the nervous system

Thyroid disorders are common in the general population and in hospitalized patients. Thyroid disease may present first with neurological complications or else may occur concurrently in patients suffering other neurological disorders, particularly those with an autoimmune etiology. For this reason neurologists will commonly encounter patients with thyroid disease. This chapter provides an overview of the neurological complications and associations of disorders of the thyroid gland. Particular emphasis is placed on conditions such as thyrotoxic periodic paralysis and myxedema coma in which the underlying thyroid disorder may be occult leading to a first, often emergency, presentation to a neurologist. Information about clinical features, diagnosis, pathogenesis, therapy, and prognosis is provided. Emphasis is placed on those aspects most likely to be relevant to the practicing neurologist and the interested reader is directed to references to good, recent review articles for further information.

Thyrotoxic periodic paralysis: diversity in America

BACKGROUND

Thyrotoxic periodic paralysis (TPP) is a potentially life-threatening complication of thyrotoxicosis, characterized by hypokalemia and muscle paralysis.

OBJECTIVE

TPP, although becoming more prevalent in western countries, is still often not recognized due to lack of familiarity and the subtlety of the thyrotoxic symptoms. Early recognition by emergency physicians can prevent potential mortality.

CASE REPORT

A 23-year-old Vietnamese male presented with a 2-h history of complete flaccid quadriplegia and chest tightness. Electrolyte studies revealed a critical potassium level of 1.4 mmol/L. The patient was admitted to the intensive care unit where further workup revealed thyrotoxicosis and the patient was subsequently diagnosed with TPP.

CONCLUSIONS

TPP should always be considered as a differential in patients, especially in young males of Asian descent with lower-limb paralysis or weakness. We present this case, followed by a review of the literature.

A 10-year analysis of thyrotoxic periodic paralysis in 135 patients: focus on symptomatology and precipitants

BACKGROUND

A comprehensive analysis has not been performed on patients with thyrotoxic periodic paralysis (TPP) characterized by acute hypokalemia and paralysis in the setting of thyrotoxicosis.

PURPOSE

The aim of this study was to analyze the detailed symptomatology of thyrotoxicosis and precipitating factors for the attack in a large cohort of TPP patients.

PATIENTS AND METHODS

A prospective observational study enrolled patients with TPP consecutively over 10 years at an academic medical center. Clinical features, including signs/symptoms of thyrotoxicosis and precipitating factors, were analyzed. The Wayne's index was used to assess the severity of thyrotoxicosis at presentation. Patients who agreed to receive an oral glucose-loading test after recovery were evaluated.

RESULTS

Among the 135 TPP patients (male:female, 130:5), 70% of paralytic attacks occurred in the morning, especially during the seasons of summer and fall. Two-thirds of patients did not have a known family or personal history of hyperthyroidism. Only 17% of TPP patients manifested overt signs/symptoms of thyrotoxicosis (Wayne's index >19). A clear precipitating factor, such as high carbohydrate load, acute upper respiratory tract infection, strenuous exercise, high-salt diet, or the use of steroids or bronchodilators, was identified in only 34% of TPP patients. A glucose load to stimulate insulin secretion induced acute hypokalemia (K(+)2.47±0.6 mmol/l) with reparalysis in only 18% (10/55) of TPP patients.

CONCLUSIONS

Most TPP patients have only subtle clinical signs/symptoms of thyrotoxicosis and only a small fraction has clear precipitating factors. In addition to the effects of hyperinsulinemia, other insulin-independent mechanisms may participate in the pathogenesis of TPP.

Thyrotoxic periodic paralysis in Chinese patients: milder thyrotoxicosis yet lower dose of (131)I should be avoided

PURPOSE

Thyrotoxic periodic paralysis (TPP) is a complication of thyrotoxicosis mainly observed in male Asian patients. It was proposed that patients with TPP tend to have lower thyroid hormone levels. We aimed to prove this observation and to assess whether a lower I dose is feasible for prompt control of TPP.

METHODS

A total of 123 male TPP patients were enrolled in this study in a 7-year period. Baseline characteristics were compared with 70 thyrotoxic patients without periodic paralysis (nTPP). Different I doses were given to 90 TPP patients with a median follow-up of 11 months, and the outcome was evaluated.

RESULTS

The serum thyroid hormone levels, including total T3 and T4, and free T3 and T4, in TPP patients were slightly less elevated compared with those in nTPP patients. Patients who received lower radioactivity of I had an unsatisfactory overall remission rate of 28.6%. Longer time to remission (P = 0.004; hazard ratio, 1.846; 95% confidence interval, 1.216-2.798) was also observed in patients with lower dose.

CONCLUSIONS

The serum thyroid hormone levels of TPP patients are lower than those of nTPP patients. Median/high dose of I is necessary to achieve rapid control of thyrotoxicosis.

Thyrotoxic periodic paralysis: clinical and molecular aspects

Thyrotoxic periodic paralysis (TPP) is a rare complication of hyperthyroidism that most often affects young East Asian males but increasingly also in other ethnic groups. The typical presentation is acute attacks varying from mild weakness to total paralysis starting at night or in the early morning a few hours after a heavy meal, alcohol abuse or strenuous exercise with complete recovery within 72 h. Signs and symptoms of hyperthyroidism may not be obvious. The hallmark is hypokalemia from increased cellular sodium/potassium-ATPase pump activity with transport of potassium from the extracellular to the intracellular space in combination with reduced potassium output. Recently, KCNJ18 gene mutations which alter the function of an inwardly rectifying potassium channel named Kir2.6 have been detected in 0-33 % of cases. Hence, the pathophysiology in TPP includes a genetic predisposition, thyrotoxicosis and environmental influences and the relative impact from each of these factors may vary. The initial treatment, which is potassium supplementation, should be given with caution due to a high risk of hyperkalemia. Propranolol is an alternative first-line therapeutic option based on the assumption that hyperadrenergic activity is involved in the pathogenesis. If thyroid function tests are unobtainable in the acute situation the diagnosis is supported by the findings of hypokalemia, low spot urine potassium excretion, hypophosphatemia with hypophosphaturia, high spot urine calcium/phosphate ratio, and electrocardiographic abnormalities as tachycardia, atrial fibrillation, high QRS voltage, and atrioventricular block. Definitive treatment is cure of the hyperthyroidism. The underlying mechanisms of TPP remain, however, incompletely understood awaiting further studies.

Parálisis periódica hipokalémica tirotóxica: reporte de un caso y revisión del tema

Se expone el caso de un hombre de 20 años, que consultó a urgencias por cuadro de 2 horas de parestesias y pérdida de la fuerza muscular en miembros inferiores, hasta incapacidad completa para incorporarse desde una silla.  Cinco episodios similares, matutinos, leves, de corta duración, con resolución espontánea, durante los últimos dos meses.  Cuatro meses antes había estado presentando palpitaciones, pérdida de 12 kilos de peso con polifagia, sensibilidad al calor, hiperdefecación y temblor fino en manos.  Se documentó y corrigió hipokalemia.  Se confirmó enfermedad de Graves dando tratamiento con propanolol y 20mCi de I131.  La parálisis periódica hipokalémica tirotóxica (PPHT) es una emergencia y puede presentarse desde debilidad muscular de predominio proximal hasta una parálisis completa con riesgo de muerte secundario a hipokalemia severa.   El diagnóstico se confirma con la presencia de signos clínicos y/ó bioquímicos de tirotoxicosis asociados a hipokalemia.  En la PPHT, hay un incremento de actividad de la bomba Na K – ATPasa dado por un aumento en la estimulación beta adrenérgica asociado a un exceso de hormona tiroidea.   Los factores precipitantes de crisis de PPHT mas frecuentes son la alta ingesta de carbohidratos y el ejercicio extenuante, aunque existen muchos otros más.  Es importante la pesquisa de hipertiroidismo en individuos con parálisis ó debilidad muscular e hipokalemia.  Ésta condición se ha descrito principalmente en hombres asiáticos, pero debe ser considerada también en nuestro medio. 

Hypokalemic periodic paralysis as first sign of thyrotoxicosis

Background: periodic paralysis related to hypokalemia is seldom reported in thyrotoxicosis, and it usually occurs in Asian males.

Patients and methods: Two Romanian (Caucasian) young patients presented with hypokalemic paralysis. TSH, FT4, TT3 was measured by immunochemiluminescence.

Case report 1. Patient O.R, aged 19, presented marked asthenia and lower limbs paralysis, following high carbohydrate meal. He declared 10 kg weight loss on hypocaloric diet and mild sweating. Biochemical data revealed moderate hypokalemia (K+=2.6 mmol/L) and thyrotoxicosis (TSH<0.03 mIU/L, FT4=30 pmol/L, TT3=315 ng/dL).

Case report 2. Patient T.A., aged 18, presented 2 episodes of weakness and flaccid paralysis, with hypokalemia, precipitated by effort, without any sign of thyrotoxicosis. Biochemical data revealed severe hypokalemia (K+=1.8 mmol/L) and thyrotoxicosis (TSH<0.03 mIU/L, FT4=24 pmol/L, TT3=190 ng/dL). Treatment with intravenous potassium, thereafter methimazole and propranolol were administered in both cases, with the maintenance of normal kalemia and thyrotoxicosis’ control.

Conclusion: these 2 cases of hypokalemic periodic paralysis occurring in young Caucasian teenagers with mild thyrotoxicosis underlined the importance of thyroid screening in patients with symptomatic hypokalemia, even in the absence of symptoms and signs of thyrotoxicosis.

Abbreviations: THPP=Thyrotoxic periodic paralysis, BMI=body mass index, TRAb=TSH receptor antibody, ECG=electrocardiogram.

Surgical treatment for thyrotoxic hypokalemic periodic paralysis: case report

Thyrotoxic hypokalemic periodic paralysis (THPP) is a rare, potentially life-threatening endocrine emergency. It is characterized by recurrent muscle weakness and hypokalemia. Because many THPP patients do not have obvious symptoms and signs of hyperthyroidism, misdiagnosis may occur. The published studies revealed that definitive therapy for THPP is control of hyperthyroidism by medical therapy, radioactive iodine or surgery, but the long-term post-operative follow-up result was not observed. We reported two cases of medically refractory THPP with recurrent paralysis of extremities and hypokalemia, and both were combined with thyroid nodules. Both patients were treated with total thyroidectomy; the pathology revealed that one is Graves' disease with thyroid papillary carcinoma, and the other is adenomatous goiter with papillary hyperplasia. No episode of periodic paralysis was noted and laboratory evaluation revealed normal potassium level during the post-operative follow up. Our experience suggests that total thyroidectomy by experienced surgeon is an appropriate and definite treatment for medically refractory THPP, especially in cases combined with thyroid nodules.

Novel etiopathophysiological aspects of thyrotoxic periodic paralysis

Thyrotoxicosis can lead to thyrotoxic periodic paralysis (TPP), an endocrine channelopathy, and is the most common cause of acquired periodic paralysis. Typically, paralytic attacks cease when hyperthyroidism is abolished, and recur if hyperthyroidism returns. TPP is often underdiagnosed, as it has diverse periodicity, duration and intensity. The age at which patients develop TPP closely follows the age at which thyrotoxicosis occurs. All ethnicities can be affected, but TPP is most prevalent in people of Asian and, secondly, Latin American descent. TPP is characterized by hypokalemia, suppressed TSH levels and increased levels of thyroid hormones. Nonselective β adrenergic blockers, such as propranolol, are an efficient adjuvant to antithyroid drugs to prevent paralysis; however, an early and definitive treatment should always be pursued. Evidence indicates that TPP results from the combination of genetic susceptibility, thyrotoxicosis and environmental factors (such as a high-carbohydrate diet). We believe that excess T(3) modifies the insulin sensitivity of skeletal muscle and pancreatic β cells and thus alters potassium homeostasis, but only leads to a depolarization-induced acute loss of muscle excitability in patients with inherited ion channel mutations. An integrated etiopathophysiological model is proposed based on molecular findings and knowledge gained from long-term follow-up of patients with TPP.

Thyrotoxic Periodic Paralysis: Case Reports and an Up-to-Date Review of the Literature

Objectives. To describe 2 cases of thyrotoxic periodic paralysis. Methods. We report of 2 cases of thyrotoxic periodic paralysis in 2 individuals from 2 different backgrounds with emphasis on their presentation and treatment. We also conducted a literature search to put together an update review of thyrotoxic periodic paralysis. Results. A 47-year-old Chinese and 28-year-old Caucasian male presented with profound yet reversible weakness associated with hypokalemia on admission bloods and thyrotoxicosis. Both were given definitive therapy to prevent recurrence of attacks with any future relapse of thyrotoxicosis. Conclusion. Thyrotoxic periodic paralysis (TPP) is a rare but potentially serious complication of thyrotoxicosis resulting in temporary but severe muscle weakness. Recent discovery of a novel mutation in the KCNJ18 gene which codes for an inwardly rectifying potassium channel and is controlled by thyroid hormones may provide greater insight into the pathogenesis of TPP.

Analytic review: thyrotoxic periodic paralysis: a review

Thyrotoxic periodic paralysis (TPP) is an unusual complication of hyperthyroidism that frequently presents in a dramatic fashion, necessitating treatment in an emergency department or admission to an intensive care unit. Thyrotoxic periodic paralysis is characterized by transient, recurrent episodes of flaccid muscle paralysis affecting proximal more severely than distal muscles. Thyrotoxic periodic paralysis is most commonly a complication of Graves' disease in Asian males, although in recent decades, an increasing number of patients from all racial and ethnic backgrounds have been reported. Thyrotoxic periodic paralysis has a higher predilection for men than women despite the fact that thyroid disease is more frequently diagnosed in women. The presence of both hypokalemia and elevated levels of triiodothyronine (T3) and thyroxine (T4) are important diagnostic features during the acute episode. Treatment of TPP involves 2 steps, immediate action to reverse the paralysis followed by measures to prevent future attacks by restoration of a euthyroid state. Although the mainstay of treating an acute attack of TPP is correction of hypokalemia to avoid fatal cardiac arrhythmias and reverse muscle weakness, it must be appreciated by treating physicians that patients with TPP do not have a total body deficiency of potassium. Close attention must be given to potassium replacement as overly aggressive treatment can result in hyperkalemia. Correction of hypokalemia and the underlying thyrotoxic state usually results in amelioration of the acute attack. This review summarizes the epidemiology, clinical manifestations, pathogenesis, diagnosis, and treatment of TPP.