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.

Childbirth with epidural analgesia in a pregnant woman with hypokalemic periodic paralysis.

Familial hypokalaemic periodic paralysis (FHPP) is an uncommon genetic disease characterized by muscle weakness associated with hypokalaemia. Episodes are precipitated by drugs, stress, metabolic diseases, hypothermia or infection. We report the case of a 38-year-old pregnant women with FHPP who underwent epidural analgesia for labour. Pregnant women with FHPP require multidisciplinary management involving an anaesthesiologist, a gynaecologist and a paediatrician. It is important to maintain normothermia, prevent hyperventilation, monitor electrolytes, avoid glucose infusions and medications that cause hypokalaemia, and administer potassium supplements when required. Locoregional techniques should be preferred over general anaesthesia. Early epidural analgesia reduces the risk of pain that could trigger an episode of FHPP. In the case of general anaesthesia, drugs that can cause malignant hyperthermia should be avoided, and short-acting non-depolarizing neuromuscular blockers with blockade-depth monitoring should be used.

Thyrotoxic periodic paralysis complicated by life-threatening acute hypercapnic respiratory failure in a Chinese male with painless thyroiditis.

CONTEXT: Thyrotoxic periodic paralysis (TPP) is a relatively common complication seen in Asian hyperthyroid patients. However, it is a rare occurrence to find a TPP case comprised of acute hypercapnic respiratory failure in patients with painless thyroiditis. PATIENT: A 29-year-old Chinese man presented with flaccid paralysis of all four limbs and he was brought to emergency room. Severe hypokalemia was found on admission. Although treatment had been initiated with potassium chloride supplementation, he went on to develop acute hypercapnic respiratory failure likely due to muscle fatigue. The patient was intubated for mechanical ventilatory support. Once his serum potassium levels were normalized, he was able to be weaned off ventilator support. Thyroid function tests showed elevated free thyroxine concentration and low thyroid-stimulating hormone concentration. He underwent a thyroid uptake scan with 131I which revealed decreased uptake rate of thyroid area. Based on the patient's clinical presentation and associated findings, we diagnosed him with TPP due to painless thyroiditis. We have reviewed TPP cases caused by painless thyroiditis and TPP cases associated with acute hypercapnic respiratory failure. CONCLUSION: It is important to note that potentially fatal complications such as acute hypercapnic respiratory failure might occur in acute attacks of TPP even in cases of TPP due to painless thyroiditis.

Thyrotoxic periodic paralysis triggered by ß2-adrenergic bronchodilators.

Hypokalemic periodic paralysis is the most common form of periodic paralysis and is characterized by attacks of muscle paralysis associated with a low serum potassium (K+) level due to an acute intracellular shifting. Thyrotoxic periodic paralysis (TPP), characterized by the triad of muscle paralysis, acute hypokalemia, and hyperthyroidism, is one cause of hypokalemic periodic paralysis. The triggering of an attack of undiagnosed TPP by ß2-adrenergic bronchodilators has, to our knowledge, not been reported previously. We describe two young men who presented to the emergency department with the sudden onset of muscle paralysis after administration of inhaled ß2-adrenergic bronchodilators for asthma. In both cases, the physical examination revealed an enlarged thyroid gland and symmetrical flaccid paralysis with areflexia of lower extremities. Hypokalemia with low urine K+ excretion and normal blood acid-base status was found on laboratory testing, suggestive of an intracellular shift of K+, and the patients' muscle strength recovered at serum K+ concentrations of 3.0 and 3.3 mmol/L. One patient developed hyperkalemia after a total potassium chloride supplementation of 110 mmol. Thyroid function testing was diagnostic of primary hyperthyroidism due to Graves disease in both cases. These cases illustrate that ß2-adrenergic bronchodilators should be considered a potential precipitant of TPP.

Complete heart block during potassium therapy in thyrotoxic periodic paralysis.

BACKGROUND: Although cardiac dysrhythmia is common in patients with thyrotoxic periodic paralysis (TPP), high-degree atrioventricular (AV) block complicated by cardiogenic shock, even under KCl supplementation, is rarely described. OBJECTIVES: To present a case of TPP in a patient who developed complete AV block with severe consequences due to paradoxical hypokalemia during KCl therapy. In addition, the management of acute hypokalemia in TPP is reviewed. CASE REPORT: A 41-year-old Chinese man with TPP presented to the Emergency Department with a 2-day history of paralysis in the extremities. He developed complete AV block with cardiogenic shock and respiratory failure, necessitating ventilatory support when plasma K(+) level decreased from 1.7 mmol/L to 1.3 mmol/L during KCl replacement of 30 mmol in 2 h. The administration of another 60 mmol KCl over 3 h achieved a plasma K(+) level of 2.1 mmol/L, resulting in the resolution of AV block and successful weaning. However, rebound hyperkalemia (K(+) 5.6 mmol/L) upon recovery was evident and uneventfully corrected. CONCLUSION: A paradoxical fall in serum K(+) concentration with potentially life-threatening complication is still underappreciated in patients with TPP on KCl supplementation. Early recognition and prompt therapy prevent untoward consequences.

An unexpected cause of proximal myopathy.

A 25-year-old man presented with a short history of profound proximal muscle weakness such that he was unable to stand. Laboratory investigations demonstrated hypokalaemia and mildly elevated serum creatine kinase. He reported a history of 8-10 episodes of less severe weakness in the preceding 8 years and his mother reported similar symptoms. The combination of weakness and hypokalaemia with a probable family history suggested the diagnosis of hypokalaemic periodic paralysis. He was treated with intravenous and oral potassium supplementation, and regained full power within 24 h.

Severe respiratory phenotype caused by a de novo Arg528Gly mutation in the CACNA1S gene in a patient with hypokalemic periodic paralysis.

Hypokalemic periodic paralysis (HOKPP) is a rare disorder characterized by episodic muscle weakness with hypokalemia. Mutations in the CACNA1S gene, which encodes the alpha 1-subunit of the skeletal muscle L-type voltage-dependent calcium channel, have been reported to be mainly responsible for HOKPP. The paralytic attacks generally spare the respiratory muscles and the heart. Here, we report the case of a 16-year-old boy who presented with frequent respiratory insufficiency during the severe attacks. Mutational analysis revealed a heterozygous c.1582C>G substitution in the CACNA1S gene, leading to an Arg528Gly mutation in the protein sequence. The parents were clinically unaffected and did not show a mutation in the CACNA1S gene. A de novo Arg528Gly mutation has not previously been reported. The patient described here presents the unique clinical characteristics, including a severe respiratory phenotype and a reduced susceptibility to cold exposure. The patient did not respond to acetazolamide and showed a marked improvement of the paralytic symptoms on treatment with a combination of spironolactone, amiloride, and potassium supplements.

[Hypokaliemic periodic paralysis and pregnancy: perinatal management. A case report]. / Paralysie périodique hypokaliémique et grossesse: prise en charge périnatale à propos d'un cas.

Familial hypokalemic periodic paralysis (FHPP) is a rare inherited disease characterized by a dysfunction of the membrane ion channels. Clinical manifestations are attacks of hypokaliemia with flaccid muscle paralysis. Paralysis is sometimes severe but always reversible with symptomatic treatment. Pregnancy and delivery have been reported to exacerbate FHPP. Authors report a case of FHPP during pregnancy with a favourable outcome. Vaginal delivery is usually possible with monitoring and epidural analgesia, avoiding active maternal expulsive efforts (passive descent of the fetus and elective outlet forceps) and other stimulating factors (carbohydrate loads, maternal stress, betamimetics, epinephrine...). Administration of IV potassium supplementation is often necessary.

An unusual cause of hypokalemic paralysis: aristolochic acid nephropathy with Fanconi syndrome.

Aristolochic acid nephropathy (AAN) with Fanconi syndrome presenting as hypokalemic paralysis is extraordinarily rare and may be unrecognized. We describe a 41-year-old man who presented with the inability to ambulate upon awakening in the morning. Physical examination revealed symmetric paralysis of bilateral lower limbs. Laboratory studies showed profound hypokalemia with renal potassium (K) wasting, hyperchloremic metabolic acidosis, hypophosphatemia with hyperphosphaturia, hypouricemia with hyperuricosuria, and glycosuria, consistent with Fanconi syndrome. Mild renal insufficiency was also observed. A meticulous search for underlying causes of Fanconi syndrome was unrevealing. However, a significant amount of aristolochic acid (AA) was detected in the consumed Chinese herb mixture (AA-I, 7 microg/g) for the treatment of his leg edema for the past 2 months. His hypokalemia, renal insufficiency, and Fanconi syndrome completely resolved 2 months after the withdrawal of Chinese herb mixture and the supplementation of potassium citrate and active vitamin D3. AAN with Fanconi syndrome should be considered as a cause of hypokalemia in any patient administered undefined Chinese herbs.