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.

A novel CACNA1S gene variant in a child with hypokalemic periodic paralysis: a case report and literature review.

BACKGROUND: The CACNA1S gene encodes the alpha 1 S-subunit of the voltage-gated calcium channel, which is primarily expressed in the skeletal muscle cells. Pathogenic variants of CACNA1S can cause hypokalemic periodic paralysis (HypoPP), malignant hyperthermia susceptibility, and congenital myopathy. We aimed to study the clinical and molecular features of a male child with a CACNA1S variant and depict the molecular sub-regional characteristics of different phenotypes associated with CACNA1S variants. CASE PRESENTATION: We presented a case of HypoPP with recurrent muscle weakness and hypokalemia. Genetic analyses of the family members revealed that the proband had a novel c.497 C > A (p.Ala166Asp) variant of CACNA1S, which was inherited from his father. The diagnosis of HypoPP was established in the proband as he met the consensus diagnostic criteria. The patient and his parents were informed to avoid the classical triggers of HypoPP. The attacks of the patient are prevented by lifestyle changes and nutritional counseling. We also showed the molecular sub-regional location of the variants of CACNA1S which was associated with different phenotypes. CONCLUSIONS: Our results identified a new variant of CACNA1S and expanded the spectrum of variants associated with HypoPP. Early genetic diagnosis can help avoid diagnostic delays, perform genetic counseling, provide proper treatment, and reduce morbidity and mortality.

Hypokalemic paralysis due to renal tubular acidosis: uncommon initial manifestation of primary Sjögren´s syndrome.

Primary Sjögren´s Syndrome is an immune-mediated disease characterized by exocrine glands dysfunction due to lymphoplasmacytic infiltration with sicca symptoms being one of its main features. The disease may, however, present as distal renal tubular acidosis due to renal involvement, which can range from asymptomatic to life-threatening. We describe the case of a 33-year-old woman with hypokalemic paralysis and metabolic acidosis secondary to distal renal tubular acidosis, leading to the diagnosis of primary Sjögren´s Syndrome. Although rare, recognizing primary Sjögren´s Syndrome as a possible cause of distal renal tubular acidosis may elicit an earlier diagnosis and treatment, improving the patient´s prognosis.

Sinus arrest in familial hypokalemic periodic paralysis caused by SCN4A mutation: a case report.

BACKGROUND: Primary hypokalemic periodic paralysis (HypoPP), a rare skeletal muscle channelopathy resulting in episodic muscle weakness or paralysis under hypokalemic conditions, is caused by autosomal-dominant genetic mutations. HypoPP limits physical activity, and cardiac arrhythmias during paralytic attacks have been reported. We describe a rare familial HypoPP case complicated by sinus arrest and syncope requiring urgent temporary pacemaker implantation. CASE REPORT: A 27-year-old Vietnamese man with a family history of periodic paralysis presented with his third attack of muscle weakness triggered by intense football training the previous day. Clinical and laboratory features justified a HypoPP diagnosis. During intravenous potassium replacement, the patient experienced syncopal sinus arrest requiring urgent temporary pacemaker implantation. The patient gradually improved, responding favorably to oral potassium supplements. Genetic testing revealed an Arg1132Gln mutation in the sodium ion channel (SCN4A, chromosome 17: 63947091). At discharge, the patient received expert consultation regarding nonpharmacological preventive strategies, including avoidance of vigorous exercise and carbohydrate-rich diet. CONCLUSIONS: No evidence has established a relationship between hypokalemia and sinus arrest, and no specific treatment exists for familial HypoPP due to SCN4A mutation. Clinician awareness of this rare condition will promote appropriate diagnostic approaches and management strategies for acute paralytic attacks. Treatment should be tailored according to HypoPP phenotypes and genotypes.

Steroid-induced hypokalemic periodic paralysis: a case report and literature review.

BACKGROUND: Hypokalemic periodic paralysis (HPP) is a rare channelopathy characterized by episodic attacks of acute muscle weakness concomitant with hypokalemia. The etiology of hypokalemia is the shift of potassium into the cells, and the clinical symptoms resolve when potassium starts to leak back to the serum. Most of the time, the underlying ion channel defects are well compensated, and an additional trigger is often required to initiate an attack. Well-known trigger factors include carbohydrate-rich meals, exercise followed by rest, stress, cold weather, and alcohol consumption. CASE PRESENTATION: Here, we present the case of a 26-year-old Asian man who suffered from an acute onset of bilateral lower limb weakness with hypokalemia following dexamethasone injection. He was diagnosed with HPP. CONCLUSIONS: We would like to remind physicians to think of steroids as an unusual precipitating factor while managing patients with HPP, per results of this case study.

Recurrent hypokalemic paralysis in hypothyroidism.

Hypothyroidism, a commonly encountered thyroid disorder, usually manifests with readily recognizable typical features. However, an unusual presentation of a classic thyroid disorder may hinder accurate diagnosis in certain instances. One such rare initial presentation of hypothyroidism is recurrent hypokalemic paralysis, and existing reports in the literature are sparse. It has been more commonly reported in thyrotoxicosis. We report the case details and clinical outcomes of two middle-aged individuals (a 34-year-old male and a 37-year-old female) with recurrent episodes of hypokalemic paralysis. Their clinical examination revealed pure motor hyporeflexia quadriparesis with hypotonia and diminished deep tendon reflexes without any autonomic dysfunction. They had no significant previous medical history. Biochemical findings revealed hypokalemia in both cases (1.4 and 1.9 mEq/L, respectively) with elevated levels of thyroid­stimulating hormone and thyroid­related antibodies in both individuals, thus, confirming the diagnosis of autoimmune hypothyroidism. Immediate treatment with intravenous and oral potassium correction helped in the recovery. Thyroxine supplementation was considered a follow-up treatment, and for a one-year follow-up period there were no complaints of limb weakness reported in both individual.

Thyrotoxic periodic paralysis associated with lactic metabolic acidosis: Case report of an African man and review of literature.

BACKGROUND: Thyrotoxic periodic paralysis (TPP) is a rare and most often acquired subtype of hypokalemic periodic paralysis. The association of varying degrees of muscle weakness, hyperthyroidism and hypokalemia characterizes it. The treatment requires potassium supplementation, control of hyperthyroidism and prevention measures. It is a frequent disease in Asian men, but much rare in Caucasian or African populations. This is the first report of TPP associated with lactic metabolic acidosis in an African man. CASE PRESENTATION: A 23 year-old African man, native from Morocco, with recurrent episodes of tetraparesis for eleven months, and abdominal pain, was referred for evaluation. Biochemical investigations showed severe hypokalemia associated with hyperthyroidism and lactic metabolic acidosis. His EKG showed signs of hypokalemia such as sinus tachycardia and U waves. After potassium supplementation, neurological recuperation was quick and complete. Thyroid ultrasound identified a hypoechogenic and hypervascularized goiter, associated with high levels of thyroid antibodies, in favor of Grave's disease. With antithyroid drugs and life-style changes, the patient did not have any other attack. REVIEW OF LITERATURE: In addition to the case report, this article presents an extended review of literature, from the first large study reporting the diagnosis and incidence of TPP in 1957 to nowadays. Are reported here the latest information concerning epidemiology, clinical manifestations, complementary examinations, management and genetic finding. The lactic acidosis observed initially is exceptional, never described in TPP. TPP is a diagnostic and therapeutic emergency, requiring careful potassium supplementation, in order to avoid the risk of the onset of rebound hyperkalemia, to be maintained until the etiological treatment is effective. Paraclinical assessment with emergency EKG and electromyogram are essential to assess the impact. DISCUSSION: It is essential in the face of any hypokalaemic periodic paralysis, including in non-Asian subjects, to search hyperthyroidism. CONCLUSIONS: This report demonstrates the importance of thyroid testing in case of acute muscle weakness, even in non-Asian patients in order to diagnose TPP. This is a rare but possible etiology, to be distinguished from the familial form of hypokalemic periodic paralysis. It also questions on the impact of TPP on energetic metabolism, in particular on lactic metabolism.

Arterial blood gas analysis aids early differential diagnosis and treatment of primary and secondary hypokalaemic periodic paralysis.

This study aimed to examine changes in electrolytes and acid-base status in primary and secondary hypokalaemic periodic paralysis (HypoPP), which will help early differential diagnosis of HypoPP. A total of 64 HypoPP patients were enrolled and relevant data from clinical records was collected. Overall, 64 patients (mean age 28.2±7.3 years) of which 58(91%) were males, with 39, 11 and 14 patients, respectively, diagnosed as primary HypoPP, thyrotoxic HypoPP, and other secondary HypoPPs at discharge, were assessed. Those with HypoPP secondary to conditions other than hyperthyroidism were more likely to develop acid-base imbalance (p<0.001); they had higher pH (p=0.046) and HCO3 levels (p=0.014) at baseline, and needed a higher dose of potassium supplement before the serum potassium level returned to normal (p=0.007) and a longer time to regain full muscle strength (p=0.004), compared with those with primary or thyrotoxic HypoPP. Emergent arterial blood gas analysis may aid early differential diagnosis of patients with primary and secondary HypoPP.

[Muscle weakness in the extremities in a man with Graves' disease].

A 42-year-old man of Chinese descent, known to have Graves' disease, presented with muscle weakness. Neurological examination showed paralysis of the arms and legs, with intact sensory function, while blood-test revealed hypokalaemia and thyrotoxicosis. The neurological symptoms resolved quickly after correction of the serum potassium level. Thyrotoxic periodic paralysis is a rare, reversible complication of hyperthyroidism is characterised by hypokalaemia, hyperthyroidism and paralysis.

Stroke-mimicking unilateral hypokalemic paralysis and literature review.

Unilateral paralysis is an alarming symptom with broad differential diagnoses, including stroke, Todd's paralysis, myelopathy, and peripheral neuropathy. Hypokalemic paralysis (HP), a neuromuscular disorder associated with muscle dysfunction, is caused by hypokalemia and manifests as symmetric proximal extremity muscle weakness. Unilateral paralysis has rarely been reported in the literature. Once hypokalemia is corrected, HP is usually reversible. Delayed diagnosis and treatment may result in fatal consequences. Here, we report an atypical case of unilateral weakness along with a review of the literature on unilateral HP.

Refractory familial hypokalaemic periodic paralysis leading to cardiovascular compromise.

Familial hypokalaemic periodic paralysis (FHPP) is a rare neuromuscular disorder that is classified under periodic paralysis (PP), which is characterised by episodes of muscle weakness. Common triggers include intense exercise, fasting or consumption of carbohydrate-rich meals. Hypokalaemic PP has an incidence of 1 in 100 000; despite the temporal association, cardiac manifestations are exceedingly rare. We present a case of FHPP, a channelopathy presenting with severe refractory hypokalaemia. The challenges with our patient were maintaining potassium levels within normal ranges and initiating a close follow-up plan. Due to the lack of clinical guidance in our case, many aspects of care, including surveillance, medications and genetic testing, remain unaddressed. Medical management includes aggressive correction with supplements, potassium-sparing diuretics and carbonic anhydrase inhibitors. Severe cases of dysrhythmias, especially ventricular fibrillation, require electrophysiology evaluation and possible implantation of a defibrillator to prevent sudden cardiac death.

The role of nephrologists in management of hypokalemic periodic paralysis: a case report.

BACKGROUND: Hypokalemic periodic paralysis is a chronic condition characterized by sporadic attacks of weakness associated with acute hypokalemia. Attacks are typically associated with specific triggers, such as prolonged rest following exercise or consumption of a high-carbohydrate meal. Most commonly, this condition is caused by an autosomal dominant calcium channel mutation, and patients typically have an established family medical history of hypokalemic periodic paralysis. Long-term complications include the development of progressive proximal myopathy. Oral potassium chloride may be considered for the treatment of an acute attack, with administration of acetazolamide or dichlorphenamide as long-term prophylaxis. Nephrologists can play an important role in the recognition and treatment of previously undiagnosed hypokalemic periodic paralysis. CASE PRESENTATION: We summarize the case of a 19-year-old white man who presented to the emergency department with undiagnosed attacks of hypokalemic periodic paralysis, and who reported, at follow-up, improvement in the severity and frequency of attacks with dichlorphenamide. CONCLUSIONS: This case demonstrates the crucial role nephrologists can play, not only in the diagnosis of hypokalemic periodic paralysis, but also in the ongoing management of this condition. Patients should be advised to regularly follow up with their nephrology team for evaluation due to the risk of developing myopathy.

Thyrotoxic periodic paralysis (TPP): assessment in the emergency department.

A male patient aged in his early twenties presented to the emergency department (ED) with quadriparesis. He was ordinarily fit and well and had exercised and eaten a carbohydrate rich meal the evening before. His point-of-care venous blood sample on arrival to the ED showed hypokalaemia of 1.6 mmol/L. (normal range=3.5-5.0 mmol/L). He was put on a cardiac monitor and started on an intravenous infusion of potassium chloride. With the benefit of hindsight, his male sex, particular features in his history and his initial ECG all pointed to a differential diagnosis of thyrotoxic periodic paralysis (TPP), although a differential diagnosis of a first attack of familial hypokalaemic paralysis was considered. As urgent thyroid function tests were sent promptly, there was minimal delay in reaching a diagnosis of TPP and promptly starting propranolol as a safe and more effective means of reversing TPP, followed by definitive treatment with carbimazole.

Novel CACNA1S mutation in hypokalaemic periodic paralysis.

A 15-year-old girl was admitted to emergency department with an acute flaccid tetraparesis with no other symptoms. A history of recurrent similar episodes with spontaneous recovery was reported and no family history was known. Laboratory tests revealed severe hypokalaemia and hypokaluria. Symptoms resolution occurred after potassium replacement. The diagnosis of hypokalaemic periodic paralysis (HPP) was confirmed by genetic testing, which revealed a not previously described mutation in CACNA1S gene (c.3715C>G p.Arg1239Gly). HPP is a rare neuromuscular disorder that causes episodic attacks of flaccid paralysis with concomitant hypokalaemia. Primary forms of the disease are skeletal muscle ion channelopathies. HPP occurs due to a problem in potassium distribution rather than a total body potassium deficiency. Therefore potassium replacement should be carefully performed because of the risk of rebound hyperkalaemia. Knowing this rare entity is important in order to avoid diagnostic delays and so that proper treatment can be initiated to reduce morbidity and mortality.

The long exercise test as a functional marker of periodic paralysis.

AIMS: The aim of this study was to evaluate the sensitivity of the long exercise test (LET) in the diagnosis of periodic paralysis (PP) and assess correlations with clinical phenotypes and genotypes. METHODS: From an unselected cohort of 335 patients who had an LET we analyzed 67 patients with genetic confirmation of PP and/or a positive LET. RESULTS: 32/45 patients with genetically confirmed PP had a significant decrement after exercise (sensitivity of 71%). Performing the short exercise test before the LET in the same hand confounded results in four patients. Sensitivity was highest in patients with frequent (daily or weekly) attacks (8/8, 100%), intermediate with up to monthly attacks (15/21, 71%) and lowest in those with rare attacks (9/16, 56%) (p = .035, Mann-Whitney U-test). Patients with a positive LET without confirmed PP mutation comprised those with typical PP phenotype and a group with atypical features. DISCUSSION: In our cohort, the LET is strongly correlated with the frequency of paralytic attacks suggesting a role as a functional marker. A negative test in the context of frequent attacks makes a diagnosis of PP unlikely but it does not rule out the condition in less severely affected patients.

Thyrotoxic periodic paralysis in two sexagenarian men: A case report.

RATIONALE: Thyrotoxic periodic paralysis (TPP) characterized by the triad of muscle paralysis, acute hypokalemia, and the presence of hyperthyroidism is often reported in young adults but rarely reported in age >60 year-old. PATIENT CONCERNS: Two sexagenarian males (age 61 and 62) presenting to the emergency department with progressive muscle paralysis for hours. There was symmetrical flaccid paralysis with areflexia of lower extremities. Both of them did not have the obvious precipitating factors and take any drugs. DIAGNOSIS: Their Wayne scores, as an objective index of symptoms and signs associated with thyrotoxicosis, were <19 (7 and 14, respectively). Their blood pressure stood 162/78 and 170/82 mm Hg, respectively. Their thyroid glands were slightly enlarged. Both of them had severe hypokalemia (1.8 and 2.0 mmol/L). Their presumptive diagnosis of mineralocorticoid excess disorders with severe potassium (K+) deficit were made. However, low urine K+ excretion and relatively normal blood acid-base status were suggestive of an intracellular shift of K+ rather than K+ deficit. Hormone studies confirmed hyperthyroidism due to Graves disease. INTERVENTIONS: A smaller dose of K+ supplementation (only a total of 50 and 70 mmol K+, respectively) were prescribed for the patient. OUTCOMES: After treatment, their serum K+ levels became normal with a full recovery of muscle strength. LESSONS: Our 2 cases highlight the fact that thyrotoxic periodic paralysis must be still kept in mind as the underlying cause of hypokalemia with paralysis and hypertension in elderly patients to avoid missing curable disorders.