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Noso S, Babaya N, Hiromine Y, Ito H, Taketomo Y, Yoshida S, Niwano F, Monobe K, Minohara T, Okada T, Tsugawa M, Kawabata Y, Ikegami H. Contribution of Asian Haplotype of KCNJ18 to Susceptibility to and Ethnic Differences in Thyrotoxic Periodic Paralysis. J Clin Endocrinol Metab 2019; 104:6338-6344. [PMID: 31361309 DOI: 10.1210/jc.2019-00672] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Accepted: 07/24/2019] [Indexed: 11/19/2022]
Abstract
CONTEXT AND OBJECTIVES Thyrotoxic periodic paralysis (TPP) is an acute complication of thyrotoxicosis that can be lethal. TPP is rare in Caucasians but often affects young men in East Asian populations. This study aimed to clarify the contribution of KCNJ18 to susceptibility to TPP in East Asian populations. PARTICIPANTS AND METHODS The study comprised 635 participants including 13 Japanese patients with TPP, 208 Japanese patients with Graves disease without TPP, and 414 healthy control subjects from the Japanese (n = 208), Korean (n = 111), and Caucasian populations (n = 95). DNA samples from 29 participants (13 with TPP, 8 with Graves disease, and 8 controls) were sequenced for KCNJ18, and all participants (n = 635) were genotyped for six variants of KCNJ18 and a polymorphism of KCNJ2 (rs312691). RESULTS Six single-nucleotide variants (SNVs) with amino acid substitutions were identified by direct sequencing of KCNJ18. Among these, four SNVs comprised three haplotypes under strong linkage disequilibrium. Haplotype 1 (AAAG) of KCNJ18 was significantly associated with susceptibility to TPP in the Japanese population (OR = 19.6; 95% CI, 1.5 to 256.9; P = 0.013). Haplotype frequencies in the general East Asian (Japanese and Korean) and Caucasian populations differed significantly (haplotype 1: 80.8% vs 48.4%, P = 1.1×10-27). CONCLUSION A major haplotype of KCNJ18 in East Asian populations is significantly associated with susceptibility to TPP. The haplotype is much more common in East Asian than Caucasian populations, suggesting its contribution to the high prevalence of TPP in East Asian populations.
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Affiliation(s)
- Shinsuke Noso
- Department of Endocrinology, Metabolism and Diabetes, Kindai University Faculty of Medicine, Osaka-sayama, Osaka, Japan
| | - Naru Babaya
- Department of Endocrinology, Metabolism and Diabetes, Kindai University Faculty of Medicine, Osaka-sayama, Osaka, Japan
| | - Yoshihisa Hiromine
- Department of Endocrinology, Metabolism and Diabetes, Kindai University Faculty of Medicine, Osaka-sayama, Osaka, Japan
| | - Hiroyuki Ito
- Department of Endocrinology, Metabolism and Diabetes, Kindai University Faculty of Medicine, Osaka-sayama, Osaka, Japan
| | - Yasunori Taketomo
- Department of Endocrinology, Metabolism and Diabetes, Kindai University Faculty of Medicine, Osaka-sayama, Osaka, Japan
| | - Sawa Yoshida
- Department of Endocrinology, Metabolism and Diabetes, Kindai University Faculty of Medicine, Osaka-sayama, Osaka, Japan
| | - Fumimaru Niwano
- Department of Endocrinology, Metabolism and Diabetes, Kindai University Faculty of Medicine, Osaka-sayama, Osaka, Japan
| | - Keisuke Monobe
- Department of Endocrinology, Metabolism and Diabetes, Kindai University Faculty of Medicine, Osaka-sayama, Osaka, Japan
| | - Tatsuro Minohara
- Department of Endocrinology, Metabolism and Diabetes, Kindai University Faculty of Medicine, Osaka-sayama, Osaka, Japan
| | - Takuya Okada
- Department of Endocrinology and Metabolism, Ikeda City Hospital, Osaka, Japan
| | - Mamiko Tsugawa
- Department of Endocrinology and Metabolism, Ikeda City Hospital, Osaka, Japan
| | - Yumiko Kawabata
- Department of Endocrinology, Metabolism and Diabetes, Kindai University Faculty of Medicine, Osaka-sayama, Osaka, Japan
| | - Hiroshi Ikegami
- Department of Endocrinology, Metabolism and Diabetes, Kindai University Faculty of Medicine, Osaka-sayama, Osaka, Japan
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Abstract
RATIONALE Thyrotoxic periodic paralysis is characterized by a sudden onset of hypokalemia and paralysis. This condition mainly affects the lower extremities and is secondary to thyrotoxicosis. The underlying hyperthyroidism is often subtle without typical symptoms such as palpitations, tremors, anxiety, and weight loss; this causes a difficulty in early diagnosis. Here, we reported a case of periodic paralysis in a patient with hyperthyroidism whose potassium level was within the normal range. PATIENT CONCERNS A 33-year-old Taiwanese man presented to the emergency department with bilateral limb weakness (more severe in the lower limbs than in the upper limbs). On arrival, the patient's vital status was stable with clear consciousness. He denied experiencing recent trauma, back pain, chest pain, abdominal pain, headache or dizziness, or a fever episode. Physical examination showed no specific findings. Neurological examination showed weakness in the muscles of the bilateral upper and lower limbs. Muscle weakness was more severe in the proximal site than in the distal site. DIAGNOSIS Blood examination showed normal complete blood count, normal renal and liver function, and normal potassium (3.5 mmol/L, normal range 3.5-5.1 mmol/L), sodium, and calcium levels; however, the examination showed impaired thyroid function (thyroid stimulating hormone: 0.04 uIU/mL, normal range 0.34-5.60 uIU/mL; free T4: 1.96 ng/dL, normal range 0.61-1.12 ng/dL). Brain computed tomography without contrast showed no obvious intra-cranial lesion. INTERVENTIONS Intravenous potassium infusion (20 mEq/L) with normal saline was prescribed for the patient. OUTCOMES After treatment, the patient felt a decrease in limb weakness. He was discharged from our emergency department with a scheduled follow-up in the endocrine outpatient department. LESSONS TPP should be considered as a differential diagnosis in young Asian men presenting with limb paralysis that is more severe in the proximal site and in the lower limbs than in the distal site and in the upper limbs, respectively. It is important for emergency department physicians to consider TPP as a differential diagnosis as it can occur even if the patient's potassium level is within the normal range.
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Affiliation(s)
- Pin-Han Wang
- Department of Emergency Medicine, Kaohsiung Medical University Hospital
| | - Kuan-Ting Liu
- Department of Emergency Medicine, Kaohsiung Medical University Hospital
- School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Yen-Hung Wu
- Department of Emergency Medicine, Kaohsiung Medical University Hospital
| | - I-Jeng Yeh
- Department of Emergency Medicine, Kaohsiung Medical University Hospital
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Shiga K, Mizuta I, Noto YI, Nakagawa M, Sasaki R, Yamawaki M. [Normokalemic periodic paralysis lasting for two weeks: a severe form of sodium channelopathy with M1592V mutation]. Rinsho Shinkeigaku 2014; 54:434-439. [PMID: 24943082 DOI: 10.5692/clinicalneurol.54.434] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
A 73-year-old man with recurrent periodic paralytic episodes lasting for two weeks each admitted to our hospital because of the leg weakness and the elevated value of serum creatine kinase. On admission, weakness in the proximal legs and mild eye lid myotonia were noted. Needle electromyography revealed abundant myotonic discharges. The prolonged exercise test showed a continuous reduction of compound muscle action potentials in the abductor digiti minimi muscle. Direct sequencing of SCN4A in the proband showed a G-to-A alteration at position 4774 that results in a change of 1592(nd) methionine to valine (M1592V). Cosegregation regarding the M1592V mutation and paralytic phenotype in this family was confirmed. Two cardinal features in this family were longer paralytic episodes compared to classical hyperkalemic/normokalemic periodic paralysis and the normal potassium value during the paralytic episodes. This study together with antecedent reports indicates that M1592V mutation shares a much greater clinical diversity ranging from congenital paramyotonia to periodic paralysis with a longer duration.
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Affiliation(s)
- Kensuke Shiga
- Department of Medical Education, Kyoto Prefectural University of Medicine
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Yao Y, Fan L, Zhang X, Xiao Z, Long Y, Tian H. Episodes of paralysis in Chinese men with thyrotoxic periodic paralysis are associated with elevated serum testosterone. Thyroid 2013; 23:420-7. [PMID: 23405854 DOI: 10.1089/thy.2011.0493] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND The strong predilection for thyrotoxic periodic paralysis (TPP) to occur in males suggests androgen may contribute to its pathogenesis. We therefore sought to determine if serum total and free testosterone (TT and FT) concentrations differed among patients with TPP during episodes of paralysis, patients with TPP between episodes of paralysis, and patients with Graves' disease (GD) not having TPP. METHODS A total of 105 Chinese men were included in the study, and were divided into three groups. Group 1 consisted of men with TPP who were studied during episodes of paralysis; group 2 consisted of men with TPP who were studied between episodes of paralysis; group 3 consisted of men with GD not having TPP. Patients in each were different persons. Serum electrolytes, free triiodothyronine (FT3), free thyroxine (FT4), TT, and FT were measured. Multiple regression analyses and analysis of covariance were performed to analyze the relationship of serum parameters, group status, and age. RESULTS One multiple regression analysis was used to determine if serum TT concentrations were associated with age, FT3, FT4, or group status. This analysis indicated that age, FT4 level, and group status were significantly and independently associated with serum TT concentrations. With regard to group status, patients in group 1 had serum TT concentrations 0.92 ng/mL higher than patients in group 3 (p=0.033). As to FT4 level, TT concentrations increased by 0.016 ng/mL for each additional pmol/L of FT4 (p=0.002). Another multiple regression analysis was used to determine if serum FT concentrations were associated with age, FT3, FT4, group status, or serum TT concentrations. This analysis revealed that serum TT concentrations and group status were significantly and independently associated with serum FT concentrations. In terms of group status, patients in group 1 had serum FT concentrations of 2.11 pg/mL greater on average than patients in group 3 (p=0.006). CONCLUSIONS We infer that episodes of paralysis in Chinese men with TPP are associated with elevated serum testosterone. We also found serum TT and FT concentrations of men with GD are both affected by group status; serum TT rather than FT concentrations are associated with thyroid function.
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Affiliation(s)
- Yu Yao
- Department of Endocrinology and Metabolism, West China Hospital, Sichuan University, Chengdu, China
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Abstract
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.
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Affiliation(s)
- Henrik Falhammar
- Department of Endocrinology, Metabolism and Diabetes, D2:04, Karolinska University Hospital, 171 76, Stockholm, Sweden.
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Lee JI, Sohn TS, Son HS, Oh SJ, Kwon HS, Chang SA, Cha BY, Son HY, Lee KW. Thyrotoxic periodic paralysis presenting as polymorphic ventricular tachycardia induced by painless thyroiditis. Thyroid 2009; 19:1433-4. [PMID: 20001723 DOI: 10.1089/thy.2009.0253] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Affiliation(s)
- Jadranka Morović-Vergles
- Division of Clinical Immunology and Rheumatology, Department of Internal Medicine, Dubrava University Hospital, Zagreb, Croatia.
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Rao N, John M, Thomas N, Rajaratnam S, Seshadri MS. Aetiological, clinical and metabolic profile of hypokalaemic periodic paralysis in adults: a single-centre experience. Natl Med J India 2006; 19:246-9. [PMID: 17203677] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
BACKGROUND Hypokalaemic periodic paralysis constitutes a heterogeneous group of disorders that present with acute muscular weakness. In this analysis, we discuss the aetiological factors that appear to be more common in the Indian population. METHODS From 1995 to 2001, 31 patients presented with periodic paralysis (mean age 34.5 years, range 11-68 years). Of the 31 patients, 19 were men. The clinical and laboratory data of these patients were analysed. Patients were investigated for possible secondary causes of hypokalaemla. RESULTS There were 13 patients (42%) with renal tubular acidosis, 13 with primary hyperaldosteronism (42%), 2 each with thyrotoxic periodic paralysis and sporadic periodic paralysis, and I with Gitelman syndrome. Of the 13 patients with renal tubular acidosis, 10 had proximal and 3 distal renal tubular acidosis. Three of these patients with renal tubular acidosis had Sjogren syndrome. The patients diagnosed to have renal tubular acidosis had significantly lower serum bicarbonate (18.7 [14.6] v. 29.6 [5.0] mEq/L; p < 0.05) and higher levels of chloride (107.5 [6.0] v. 99.5 [3.4] mEq/L; p < 0.05) compared with those who had primary hyperaldosteronism, although the potassium values were similar (2.4 [0.65] v. 2.26 [0.48] mEq/L; p = 0.43). All patients with primary hyperaldosteronism had hypertension at presentation and were proven to have adrenal adenomas. CONCLUSION A significant number of patients in this study had secondary and potentially reversible causes of hypokalaemic periodic paralysis. The common causes were renal tubular acidosis and primary hyperaldosteronism. A detailed work-up for secondary causes should be undertaken in Indian patients with hypokalaemic periodic paralysis.
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Affiliation(s)
- Narsing Rao
- Department of Endocrinology, Diabetes and Metabolism, Christian Medical College, Ida Scudder Road, Vellore 632004, Tamil Nadu, India
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Wild E. Thyrotoxic periodic paralysis in a Maori patient. N Z Med J 2004; 117:U1204. [PMID: 15608800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
Abstract
A case of thyrotoxic periodic paralysis (TPP) in a patient of Maori heritage is described. The epidemiology, aetiology and pathogenesis of TPP are discussed. The case demonstrates that neurological examination and biochemical findings may be normal between episodes of paralysis. Given that there is much racial variation in the prevalence of TPP, and the suggestion that non-thyrotoxic periodic paralysis may be more prevalent in Maori, the case highlights the need for more research into the prevalence and pathogenesis of TPP in Maori patients.
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Affiliation(s)
- Edward Wild
- Department of Neurology, Wellington Hospital, Wellington, New Zealand.
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Abstract
Andersen's Syndrome is a rare disease, hereditary with autosomal dominant transmission, of the ion channels of the sarcolemmal membranes of the cardiac and skeletal muscles (channelopathy), which affects chromosome 17 of the KCNJ2 gene, responsible for encoding the outward potassium delayed rectifier current KIR2.1, resulting in a loss or suppression of the function of this channel.
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Abstract
Hypokalemic paralysis associated with hyperthyroidism (TPP) is a well-known acute electrolyte and muscle function disorder. Lesser known is normokalemic periodic paralysis associated with hyperthyroidism. We describe two cases of young men with acute muscular paralysis and bilateral impairment of sensation over the lower legs who had normal plasma potassium concentrations. They were initially misdiagnosed as having Guillain-Barré syndrome or hysterical paralysis. However, thyroid function tests showed elevated serum T(3) and T(4) and markedly depressed thyroid-stimulating hormone findings consistent with hyperthyroidism. Control of the hyperthyroidism completely abolished their periodic paralysis. Thyrotoxic normokalemic periodic paralysis (TNPP) should be kept in mind as a cause of acute muscle weakness to avoid missing a treatable and curable condition.
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Affiliation(s)
- Chia-Chao Wu
- Division of Nephrology, Department of Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
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Abstract
A 24 year old white woman presented with sudden onset of flaccid quadriparesis and hypokalaemia. She was later found to be thyrotoxic. Paralysis resolved with potassium supplements, and after initiation of antithyroid medication she had no further episodes of hypokalaemic paralysis. To the best of the authors' knowledge, and after a Medline search, thyrotoxic periodic paralysis has not been described previously in a white woman.
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Affiliation(s)
- A N Dixon
- Department of Medicine, Princess Royal Hospital NHS Trust, Apley Castle, Telford, Shropshire TF6 6TF, UK.
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Abstract
PURPOSE The aim of the study was to describe the sonographic appearances of the thyroid in patients with thyrotoxic periodic paralysis (TPP). METHODS Of the 25 patients diagnosed with TPP between January 1, 1998, and December 31, 2001, as identified by a search of our patient database, 13 had undergone sonography of the thyroid. We retrospectively reviewed the clinical records and thyroid sonograms of these 13 patients. The sonograms were assessed subjectively for thyroid size, echogenicity, vascularity, and the presence of solid nodules and cysts. RESULTS Sonography showed abnormality of the thyroid in all 13 patients. In 11 patients (85%), sonography showed widespread hypoechogenicity (compared with the muscle) whose distribution was diffuse (6 patients) or patchy (5 patients) and diffusely distributed areas of hypervascularity (type 1 pattern). All 11 of these patients had a clinical diagnosis of Graves' disease. One patient (8%) had multinodular goiter and enlargement of the thyroid with multiple heterogeneous solid nodules and cysts (type 2 pattern); the clinical diagnosis was toxic multinodal goiter. One patient (8%) had a combination of type 1 and type 2 patterns and a clinical diagnosis of Graves' disease. CONCLUSIONS The sonographic abnormalities of the thyroid in patients with TPP reflect the common underlying causes of thyrotoxicosis in the general population. The sonographic appearances associated with Graves' disease (type 1 pattern) were the most common abnormality detected. No sonographic features specific to TPP were identified.
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Affiliation(s)
- Ann D King
- Department of Diagnostic Radiology and Organ Imaging, Faculty of Medicine, The Chinese University of Hong Kong, Prince of Wales Hospital, 30-33 Ngan Shing Street, Shatin, New Territories, Hong Kong
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Kurihara T. [Normokalemic periodic paralysis]. Ryoikibetsu Shokogun Shirizu 2002:134-6. [PMID: 11555890] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Affiliation(s)
- T Kurihara
- Fourth Department of Internal Medicine, Toho University School of Medicine
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Abstract
OBJECTIVES This study was done to describe the features of thyrotoxic periodic paralysis in young Asian men. METHODS Seven male patients were enlisted who presented to the emergency department over a period of three years with weakness and paralysis in the morning. RESULTS Initial electrolyte studies revealed hypokalaemia in these patients, and later thyroid function tests confirmed thyrotoxicosis for all. Only two of these patients had clinical symptoms and signs of thyrotoxicosis, the others being asymptomatic. CONCLUSIONS Early morning paralysis can be the first manifestation of hyperthyroidism in Asian men, without the other more typical symptoms of weight loss, increased appetite, excitability, sweaty palms or goitre. Treatment to a euthyroid state will ameliorate the syndrome.
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Messina G, Savina A. [A rare case of hypokalemic thyrotoxic periodic paralysis in a Caucasian patient with Basedow's disease]. Recenti Prog Med 1999; 90:392-3. [PMID: 10429519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
Thyrotoxicosis periodic paralysis is a very rare complication of thyrotoxicosis in whites, but is more frequently reported in oriental and latin american populations and associates the clinical picture of hyperthyroidism with bouts of paralysis due to hypokalemia. The hypokalemia is due to a massive shift of potassium from the extra- to the intracellular compartment. In this paper the authors report a case of 34-years old white male with an history of hypokalemic periodic paralysis and hyperthyroidism, studied with potassium, thyroid hormone, TSH and thyroid antibodies sampling and thyroid ultrasonography with color-Doppler. The restoration of a euthyroid state with methimazole and propranolol was effective in preventing further episodes of paralysis. It is suggested that the mechanism for the development of the hypokalemic periodic paralysis is the intracellular blockade of potassium by the surplus of thyroid hormones.
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Affiliation(s)
- G Messina
- Servizio di Osservazione Medica e Pronto Soccorso, Ospedale Madre G. Vannini, Roma
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Abstract
BACKGROUND Hypokalemia is a well-known, consistent finding in thyrotoxic periodic paralysis (TPP). It is less well known that hypophosphatemia and mild hypomagnesemia are often present in TPP and that rebound hyperkalemia can occur as a result of potassium therapy. OBJECTIVE To report the prevalence of these electrolyte abnormalities in 24 episodes of TPP in 19 patients admitted to a single university-affiliated public hospital during a 15-year period. METHODS The medical records of all patients admitted to the Santa Clara Valley Medical Center in San Jose, Calif, between August 1, 1982, and June 1, 1997, with any type of hypokalemic periodic paralysis were reviewed. In patients with TPP, serum potassium, phosphorus, and magnesium levels were evaluated during and after episodes of paralysis. The administered dose of potassium chloride, recovery time from hypokalemia, and prevalence of rebound hyperkalemia after recovery were also ascertained. Data are presented as mean +/- SD. RESULTS Hypokalemia was present in all 24 initial episodes of TPP, with serum potassium levels ranging from 1.1 to 3.4 mmol/L (mean, 1.9+/-0.5 mmol/L). After recovery from hypokalemia, the maximum serum potassium level significantly increased, ranging from 4.0 to 6.6 mmol/L (mean, 4.9+/-0.5 mmol/L; P<.001). In 10 (42%) of 24 episodes, rebound hyperkalemia (serum potassium level >5.0 mmol/L) was present. Recovery time did not correlate with the potassium chloride dose administered (r = 0.17). Initial serum phosphorus levels ranged from 0.36 to 0.97 mmol/L (mean, 0.61+/-0.23 mmol/L) (1.1-3.0 mg/dL [mean, 1.9+/-0.7 mg/dL]), with hypophosphatemia present in 12 (80%) of 15 episodes. Serum phosphorus levels significantly increased (P<.01), to 1.26 to 1.74 mmol/L (mean, 1.48+/-0.16 mmol/L) (3.9-5.4 mg/dL [mean, 4.6+/-0.5 mg/dL]), with or without phosphorus replacement therapy. A slight increase in serum magnesium levels after paralysis resolved was observed in all patients (P<.07). No further episodes of paralysis occurred in any patients after they became euthyroid. CONCLUSIONS Hypokalemia, hypophosphatemia, and mild hypomagnesemia are characteristic features of TPP. Hypokalemia occurred in 100% and hypophosphatemia in 80% of the episodes in our study. Rebound hyperkalemia is a potential hazard of potassium administration and occurred in 42% of 24 episodes.
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Affiliation(s)
- M A Manoukian
- Department of Medicine, Santa Clara Valley Medical Center, San Jose, Calif 95128, USA
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Sloet van Oldruitenborgh-Oosterbaan MM. [HYPP: hyperkalemic periodic paralysis in the horse]. Tijdschr Diergeneeskd 1999; 124:176-81. [PMID: 10188180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
Hyperkalaemic periodic paralysis(HYPP) is characterized by intermittent episodes of muscular tremor, weakness, and collapse, and is probably caused by abnormal electrolyte transport in the muscle cell membrane. During an episode of HYPP, most animals are severely hyperkalaemic. HYPP is a hereditary disease and occurs only in American Quarter horses or crossbreds. Because these horses are now being imported into the Netherlands, HYPP should be included in the differential diagnosis of horses showing signs of muscle tremor, paresis, or paralysis. The present article reviews the literature on HYPP and describes a case showing typical signs of the disease.
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Penisson-Besnier I, Letournel F, Kerkeni N, Dubas F, Alquier P, Rohmer V. [Periodic hypokalemic paralysis disclosing thyrotoxicosis]. Presse Med 1998; 27:1430-1. [PMID: 9793040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/09/2023] Open
Abstract
BACKGROUND Hypokaliemic periodic paralysis is an uncommon complication of hyperthyroidism occurring sporadically almost exclusively in young Asian men. The clinical presentation is the same as in familial hypokaliemic periodic paralysis. Treatment consists of conventional management for thyrotoxicosis. CASE REPORT A Laotian man aged 42 years had suffered episodes of pain and fatigue in the lower limbs lasting 2 to 7 days over the last few months. The patient was hospitalized with severe limb pain. Clinical examination found severe motor deficit involving all four limbs. Laboratory findings induced hypokaliemia (1.8 mmol/l) and hyperthyroidism (free thyroxin 36 pmol/l, TSH < 0.005 mlU/l). Thyroid echography revealed multinodular goitre with two heterogeneous nodules. Strong uptake was seen on the scintigram. The motor deficit regressed within 8 hours and the kaliemia was restored with 1.50 g KCl. The patient was discharged with carbimazole (30 mg/d). Three months later he was euthyroid and symptom free. Total thyroidectomy was performed and L-thyroxin prescribed. The patient remains symptom-free at the last follow-up, 5 months after thyroidectomy. DISCUSSION The pathogenesis of hypokaliemic periodic paralysis involves the ATPase-dependent sodium-potassium pump whose activity is stimulated by thyroid hormones. The reasons for the ethnic and male predominance are poorly elucidated.
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Shishiba Y. [Current status of clinical and molecular-biological research on familial periodic paralysis]. Nihon Rinsho 1997; 55:3239-46. [PMID: 9436444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Types of periodic paralysis seen in Japan are numerous: the one most frequently seen is hypokalemic periodic paralysis. Among them, approximately 50% are secondary to thyrotoxicosis. Number of families of familial hyperkalemic periodic paralysis have also been reported so far. Several cases of hyperkalemic periodic paralysis secondary to thyrotoxicosis have also been reported exclusively from Japan. As the pathogenesis of hypokalemic periodic paralysis, depolarization block induced by membrane permeability change in the face of hypokalemia triggered by excess insulin was strongly suggested and supported experimentally in part. Recent linkage analysis on familial hypokalemic periodic paralysis revealed that the abnormality is linked to a mutation in voltage-gated Ca channel. The difficulty remains how to explain the cause of hypokalemia which is almost always preceding the attack of periodic paralysis of this type. The cause of hyperkalemic periodic paralysis was shown to be the mutation in voltage-gated Na channel. Failure of inactivation of the channel causes an increase in inward sodium current which results in depolarization and accumulation of potassium. The explanation of the pathogenesis of paralysis is straight-forward when compared to that of hypokalemic periodic paralysis.
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Koul PA, Bhat D. Distal renal tubular acidosis and hypokalemic paralysis--genetic and precipitating factors. J Assoc Physicians India 1996; 44:752-3. [PMID: 9251363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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Horne M. Periodic paralyses. Aust Fam Physician 1996; 25:1331. [PMID: 8771893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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27
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Bailey JE, Pablo L, Hubbell JA. Hyperkalemic periodic paralysis episode during halothane anesthesia in a horse. J Am Vet Med Assoc 1996; 208:1859-65. [PMID: 8675475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
A 7-month-old Quarter Horse filly was admitted for surgical repair of a right olecranon fracture. Anesthesia was achieved with xylazine hydrochloride, guaifenesin, ketamine hydrochloride, and halothane. Two and a half hours after induction of anesthesia, myotonia, muscle fasciculations, and sweating, concurrent with high serum potassium concentration and associated electrocardiographic changes consistent with hyperkalemic periodic paralysis, were observed. Treatment included intermittent positive-pressure ventilation, changing intravenous administration of fluids from lactated Ringer's solution to 0.9% NaCl solution, and administration of calcium gluconate, glycopyrrolate, dopamine, and sodium bicarbonate. Clinical signs resolved with the return of serum potassium concentrations to the reference range. The horse was confirmed to be heterozygous for hyperkalemic periodic paralysis by DNA testing.
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MESH Headings
- Anesthesia, General/adverse effects
- Anesthesia, General/veterinary
- Anesthetics, Inhalation/adverse effects
- Animals
- Blood Gas Analysis/veterinary
- Blood Pressure
- Breeding
- Electrocardiography/veterinary
- Female
- Fractures, Bone/surgery
- Fractures, Bone/veterinary
- Halothane/adverse effects
- Heterozygote
- Horse Diseases/etiology
- Horse Diseases/genetics
- Horses
- Hyperkalemia/etiology
- Hyperkalemia/genetics
- Hyperkalemia/veterinary
- Intraoperative Complications/veterinary
- Muscle, Skeletal/physiopathology
- Paralyses, Familial Periodic/etiology
- Paralyses, Familial Periodic/genetics
- Paralyses, Familial Periodic/veterinary
- Respiration, Artificial/veterinary
- Ulna/injuries
- Ulna/surgery
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Affiliation(s)
- J E Bailey
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Ohio State University, Columbus 43210-1089, USA
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28
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Thomas N, Ramakrishna B, Seshadri MS. Hypokalemic periodic paralysis: an unusual cause. J Assoc Physicians India 1996; 44:207-8. [PMID: 9251321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- N Thomas
- Department of Pathology, Christian Medical College and Hospital Vellore
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29
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Lerche H, Klugbauer N, Lehmann-Horn F, Hofmann F, Melzer W. Expression and functional characterization of the cardiac L-type calcium channel carrying a skeletal muscle DHP-receptor mutation causing hypokalaemic periodic paralysis. Pflugers Arch 1996; 431:461-3. [PMID: 8584443 DOI: 10.1007/bf02207287] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
A histidine substitution for the outermost arginine in II/S4 of the alpha1 subunit of the human skeletal muscle dihydropyridine (DHP) receptor has been reported to cause hypokalaemic periodic paralysis (HypoPP). This mutation shifts the voltage dependence of L-type Ca curent inactivation in myotubes from HypoPP patients by -40 mV without affecting activation. Based on the strong homology of II/S4 in cardiac and skeletal muscle alpha1, we introduced the corresponding mutation into the rabbit cardiac alpha1 subunit (R650H). Wild type (WT) and mutant constructs were transiently transfected in HEK cells together with beta and alpha2delta subunits and Ca and Ba currents were studied using the whole-cell patch-clamp technique. In contrast to the results obtained from human myotubes, R650H produced a small (-5 mV) but significant shift of both the steady-state activation and inactivation curves. When external pH was increased from 7.4 to 8.4 in order to favour deprotonization of H650, the only difference between WT and mutant channels was a slightly reduced steepness of the inactivation curve. Additional cotransfection of the gamma subunit which is only found in skeletal but not in heart muscle, shifted the inactivation curves of both WT and R650H by -20 mV. We conclude that R650 plays a different role in voltage-dependent gating of the cardiac L-type Ca channel than the corresponding residue in the human skeletal muscle L-type channel, since a distinct and selective effect on the midpoint voltage of steady-state inactivation could not be found for R650H.
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Affiliation(s)
- H Lerche
- Abteilung für Angewandte Physiologie, Universität Ulm, D-89069 Ulm, Germany
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30
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Gao X, Tang X, Du H, Li B. A clinical and neuroelectrophysiological study of hyperkalemic periodic paralysis. Chin Med Sci J 1995; 10:116-118. [PMID: 7647318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
A case of atypical hyperkalemic periodic paralysis is reported. The diagnosis was confirmed by hyperkalemic test, cold water test, and differentiation of attack period and rest period by the measurement of motor nerve conduction amplitude. Etio-pathology of this disease is discussed from the view of neuroelectrophysiology.
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31
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Kemperman FA, Hoff HC, de Klerk G. [Hypokalemic periodic paralysis as the sole manifestation of hyperthyroidism]. Ned Tijdschr Geneeskd 1995; 139:938-41. [PMID: 7753227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Hypopotassaemic periodic paralysis as the sole manifestation of hyperthyroidism. Hypopotassaemic periodic paralysis is a rare disorder that is found in certain families, sporadically or in association with certain diseases. The association with hyperthyroidism is almost wholly restricted to south-east Asian males. It is characterized by attacks of subacute paralysis, starting most often early in the morning and lasting some hours to a few days. We present a 42-year-old patient of Indonesian origin, who experienced four attacks of paralysis before underlying hyperthyroidism was diagnosed. The mechanism is based on potassium shift into the muscle cell due to higher activity of the Na-K-ATP-ase pump, under the influence of beta-adrenergic stimulation and thyroid hormone. Treatment with antithyroidal medication and beta-blockers led to the complete abolition of attacks.
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Affiliation(s)
- F A Kemperman
- Afd, Interne Geneeskunde, Kennemer Gasthuis, IJmuiden
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32
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Piraino Neuenschwander P, Pumarino Carte H, Bidegain González F, Zura Jiménez ML, Ferreiro Merino F. [Thyrotoxic hypokalemic periodic paralysis: 18 cases with different forms of thyrotoxicosis]. Rev Clin Esp 1995; 195:294-7. [PMID: 7617935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Thyrotoxic periodic paralysis (TPP) is a rare complication of thyrotoxicosis in whites but it is commonly reported in oriental populations. Eighteen males with TPP were studied from 1966 to 1993 (17 years) with a mean age of 32.8 years (range: 22-50 years). Their ancestor, traced back as possible, was hispanic in 15 and autoctonous indigens (mapuche) in three. They had one or more episodes of flaccid paralysis with complete recovery associated with thyrotoxicosis and hypokalemia (in the twelve patients who had their serum potassium determined). Two patients had respiratory compromise. Ten patients had their crisis onset after physical exertion and/or copious ingestion of carbohydrates. Only one of the patients had severe thyrotoxicosis and the diagnosis was made after the periodic paralysis in ten of them. The types of thyrotoxicosis associated with TPP were: Graves-Basedow disease in 13, subacute thyroitidis in three, and overdosage of thyroid hormone in two patients. In summary, TPP can occur in latin american populations, may be fatal, and is not always associated with Graves-Basedow disease.
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Affiliation(s)
- P Piraino Neuenschwander
- Departamento de Medicina, Hospital Clínico de la Universidad de Chile José Joaquín Aguirre, Santiago
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33
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Karantzias J, Giovannani A, Lago C, Diab M, Bagilet D. [Hypokalemic paraparesis caused by iatrogenic hyperthyroidism]. Rev Clin Esp 1995; 195:360-1. [PMID: 7617951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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34
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García García I, Ciudad Bautista J, Moreno Ruiz I, Martín González T, del Cañizo Gómez FJ, de Diego Gómez JM. [Thyrotoxic periodic paralysis in a Spanish male]. Rev Clin Esp 1995; 195:302-3. [PMID: 7617937] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
One of the few cases of thyrotoxic periodic paralysis in our country is reported. A twenty-one year old male patient with Graves disease for more than three years had a poor compliance with the therapeutical regimen, with mainly nightly episodes of self-limited limb weakness associated with hypokalemia. The patient has no familiar antecedents of periodic paralysis and the clinical manifestations resolved with treatment of hyperthyroidism.
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Affiliation(s)
- I García García
- Servicio de Medicina Interna, Hospital Virgen de la Concha, Zamora
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35
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Marlier S, Raccah D, Disdier P, Molle L, Harle JR, Vialettes B, Weiller PJ. [Thyrotoxic periodic paralysis. Discussion of the role of Na-K-ATPase, apropos of a case]. Rev Med Interne 1995; 16:209-11. [PMID: 7740232 DOI: 10.1016/0248-8663(96)80693-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
We report a case of thyrotoxicosis periodic paralysis (TPP), occurring as a complication of a Grave's disease in a 31 year-old Caucasian male. It has been suggested that the membrane Na-K pump was involved in the pathogenesis of this complication. In our patient, before treatment, the activity of erythrocyte Na-K-ATPase was significantly decreased, as compared with healthy subjects (228nmol Pi/mg prot/h versus 298 + 60 nmol Pi/mg prot/h) and went back to normal levels post treatment. The activity of this enzyme seems to be prone to genetics factors as well as environmental ones. This would explain the higher incidence of TPP in male and in asiatic people. However, other reports emphasize the role of Na-K-pump-independent potassium influx, which would be more specific of TPP.
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Affiliation(s)
- S Marlier
- Service de médecine interne, hôpital de la Timone, Marseille, France
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36
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Abstract
Twenty patients with periodic paralysis were evaluated and the aspects studied included epidemiological data, clinical manifestations, ancillary tests, treatment and evolution. Sixteen patients had the hypokalemic form (5 familiar, 5 sporadic, 5 thyrotoxic and 1 secondary). No patient with the normokalemic form was detected. Predominance of men was found (14 patients), especially in the cases with hyperthyroidism (5 patients). No thyrotoxic patient was of oriental origin. Only 4 patients had the hyperkalemic form (3 familiar, 1 sporadic). Attacks of paralysis began during the first decade in the hyperkalemic form and up to the third decade in the hypokalemic. In both forms the attacks occurred preferentially in the morning with rest after exercise being the most important precipitating factor. Seventy five percent of the hyperkalemic patients referred brief attacks (< 12 hours). Longer attacks were referred by 43% of the hypokalemic patients. The majority of the attacks manifested with a generalized weakness mainly in legs, and its frequency was variable. Creatinokinase was evaluated in 10 patients and 8 of them had levels that varied from 1.1 to 5 times normal. Electromyography was done in 6 patients and myotonic phenomenon was the only abnormality detected in 2 patients. Carbonic anhydrase inhibitors, especially acetazolamide, were used for prophylactic treatment in 9 patients with good results in all. Although periodic paralysis may be considered a benign disease we found respiratory distress in 5 patients, permanent myopathy in 1, electrocardiographic abnormalities during crises in 4; death during paralysis occurred in 2. Therefore correct diagnosis and immediate treatment are crucial. This study shows that hyperthyroidism is an important cause of periodic paralysis in our country, even in non oriental patients. Hence endocrine investigation is mandatory since this kind of periodic paralysis will only be abated after return to the euthyroid state.
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Affiliation(s)
- C H Tengan
- Disciplina de Neurologia, Escola Paulista de Medicina, São Paulo, Brasil
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Affiliation(s)
- D Ghosh
- Department of Neurology, Sanjay Gandhi PGI of Medical Sciences, Lucknow, India
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38
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Abstract
Thyrotoxic periodic paralysis (TPP) is an unusual complication of a fairly common disease affecting mostly Asian males. In the United States, there have been several reports of TPP in different ethnic populations and it appears that the incidence is approximately one-tenth of that found in Asian countries. Only six reports of TPP in African-Americans could be found in the literature; however, we are reporting four cases diagnosed within a 13-year period at our institution. We conclude that TPP may occur more often in Blacks than previously suspected and should be considered when patients present with unexplained hypokalemia, muscular weakness and rhabdomyolysis. The epidemiology, clinical manifestations, pathophysiology, and treatment of TPP are reviewed.
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Affiliation(s)
- R E Kilpatrick
- Department of Medicine, Louisiana State University Medical Center, Shreveport
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39
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Stewart RH, Bertone JJ, Yvorchuk-St Jean K, Reed SM, Neil WH. Possible normokalemic variant of hyperkalemic periodic paralysis in two horses. J Am Vet Med Assoc 1993; 203:421-4. [PMID: 8226220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Hyperkalemic periodic paralysis (HPP), characterized by intermittent episodes of muscle fasciculations, profound muscle weakness, and hyperkalemia, has been described in Quarter Horses, Appaloosas, and Paints. In previous reports, the hallmark of this syndrome has been the development of hyperkalemia during each episode. Two affected horses had episodes of paralysis without associated hyperkalemia, demonstrating that normokalemia during an episode otherwise consistent with HPP does not eliminate HPP as a diagnosis. This clinical presentation appeared to be a variant of HPP.
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Affiliation(s)
- R H Stewart
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Ohio State University, Columbus 43210
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40
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Cannon SC, Corey DP. Loss of Na+ channel inactivation by anemone toxin (ATX II) mimics the myotonic state in hyperkalaemic periodic paralysis. J Physiol 1993; 466:501-20. [PMID: 8105077 PMCID: PMC1175489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
1. Mutations that impair inactivation of the sodium channel in skeletal muscle have recently been postulated to cause several heritable forms of myotonia in man. A peptide toxin from Anemonia sulcata (ATX II) selectively disrupts the inactivation mechanism of sodium channels in a way that mimics these mutations. We applied ATX II to rat skeletal muscle to test the hypothesis that myotonia is inducible by altered sodium channel function. 2. Single-channel sodium currents were measured in blebs of surface membrane that arose from the mechanically disrupted fibres. ATX II impaired inactivation as demonstrated by persistent reopenings of sodium channels at strongly depolarized test potentials. A channel failed to inactivate, however, in only a small proportion of the depolarizing steps. With micromolar amounts of ATX II, the ensemble average open probability at the steady state was 0.01-0.02. 3. Ten micromolar ATX II slowed the relaxation of tension after a single twitch by an order of magnitude. Delayed relaxation is the in vitro analogue of the stiffness experienced by patients with myotonia. However, peak twitch force was not affected within the range of 0-10 microM ATX II. 4. Intracellular injection of a long-duration, constant current pulse elicited a train of action potentials in ATX II-treated fibres. After-depolarizations and repetitive firing often persisted beyond the duration of the stimulus. Trains of action potentials varied spontaneously in amplitude and firing frequency in a similar way to the electromyogram of a myotonic muscle. Both the after-depolarization and the post-stimulus firing were abolished by detubulating the fibres with glycerol. 5. We conclude that a loss of sodium channel inactivation alone, without changes in resting membrane conductance, is sufficient to produce the electrical and mechanical features of myotonia. Furthermore, in support of previous studies on myotonic muscle from patients, this model provides direct evidence that only a small proportion of sodium channels needs to function abnormally to cause myotonia.
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Affiliation(s)
- S C Cannon
- Department of Neurology, Howard Hughes Medical Institute, Massachusetts General Hospital, Boston 02114
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41
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Abstract
Muscle fibers from individuals with hyperkalemic periodic paralysis generate repetitive trains of action potentials (myotonia) or large depolarizations and block of spike production (paralysis) when the extracellular K+ is elevated. These pathologic features are thought to arise from mutations of the sodium channel alpha subunit which cause a partial loss of inactivation (steady-state Popen approximately 0.02, compared to < 0.001 in normal channels). We present a model that provides a possible mechanism for how this small persistent sodium current leads to repetitive firing, why the integrity of the T-tubule system is required to produce myotonia, and why paralysis will occur when a slightly larger proportion of channels fails to inactivate. The model consists of a two-compartment system to simulate the surface and T-tubule membranes. When the steady-state sodium channel open probability exceeds 0.0075, trains of repetitive discharges occur in response to constant current injection. At the end of the current injection, the membrane potential may either return to the normal resting value, continue to discharge repetitive spikes, or settle to a new depolarized equilibrium potential. This after-response depends on both the proportion of noninactivating sodium channels and the magnitude of the activity-driven K+ accumulation in the T-tubular space. A reduced form of model is presented in which a two-dimensional phase-plane analysis shows graphically how this diversity of after-responses arises as extracellular [K+] and the proportion of noninactivating sodium channels are varied.
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Affiliation(s)
- S C Cannon
- Department of Neurology, Massachusetts General Hospital, Boston 02114
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42
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Abstract
Acute hypokalemic paralysis is an uncommon cause of acute weakness. Morbidity and mortality associated with unrecognized disease include respiratory failure and death. Hence, it is imperative for physicians to be knowledgeable about the causes of hypokalemic paralysis, and consider them diagnostically. The hypokalemic paralyses represent a heterogeneous group of disorders with a final common pathway presenting as acute weakness and hypokalemia. Most cases are due to familial hypokalemic paralysis; however, sporadic cases are associated with diverse underlying etiologies including thyrotoxic periodic paralysis, barium poisoning, renal tubular acidosis, primary hyperaldosteronism, licorice ingestion, and gastrointestinal potassium losses. The approach to the patient with hypokalemic paralysis includes a vigorous search for the underlying etiology and potassium replacement therapy. Further therapy depends on the etiology of the hypokalemia. Disposition depends on severity of symptoms, degree of hypokalemia, and chronicity of disease.
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Affiliation(s)
- R E Stedwell
- Department of Emergency Medicine, Texas Tech University Health Sciences Center, El Paso 79905
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Abstract
A paralysis attack was induced by glucose load in a patient with hypokalemic periodic paralysis. A profound drop in serum phosphorus was observed (from 3.0 to 0.8 mg/dl) in parallel to the serum potassium decrease. The potential role of phosphorus metabolism in the pathophysiology of muscle weakness in this disease is discussed.
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Affiliation(s)
- R Delage
- Laval University Research Center, L'Hôtel-Dieu de Québec, Canada
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44
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Ramos Rincón JM, Rábano Gutiérrez del Arroyo J, González Muñoz MA, Arroyo Serrano S. [Thyrotoxic periodic paralysis]. Med Clin (Barc) 1990; 94:158. [PMID: 2325472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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45
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Oh VM, Taylor EA, Yeo SH, Lee KO. Cation transport across lymphocyte plasma membranes in euthyroid and thyrotoxic men with and without hypokalaemic periodic paralysis. Clin Sci (Lond) 1990; 78:199-206. [PMID: 2155749 DOI: 10.1042/cs0780199] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
1. To study potassium transport in hypokalaemic periodic paralysis in a model of striated muscle cells, we measured specific [3H]ouabain binding (the number of sodium-potassium pumps), sodium-potassium-pump-mediated (ouabain-sensitive) 86Rb+ influx and sodium-potassium-pump-independent (ouabain-resistant) 86Rb+ influx in lymphocytes in vitro. 2. The subjects comprised euthyroid and thyrotoxic men with hypokalaemic periodic paralysis between attacks, men with uncomplicated thyrotoxicosis, and healthy men matched for age and weight. 3. Thyrotoxic patients, both with and without periodic paralysis, had significantly more lymphocyte sodium-potassium pumps than normal, and a significantly greater sodium-potassium-pump-mediated 86Rb+ influx. Anti-thyroid treatment corrected this defect in patients with thyrotoxic periodic paralysis. Euthyroid patients with cryptogenic periodic paralysis had significantly increased sodium-potassium-pump-mediated 86Rb+ influx, but a normal number of sodium-potassium pumps. 4. Only untreated thyrotoxic and euthyroid patients with periodic paralysis showed a significant increase in sodium-potassium-pump-independent 86Rb+ influx (5.2 +/- 2.8 and 4.5 +/- 1.8 respectively, vs control 2.8 +/- 1.0 pmol h-1 10(-6) cells; mean +/- SD; P less than 0.001, P less than 0.005). 5. We conclude that thyrotoxicosis increases the number and activity of sodium-potassium pumps and facilitates, but is probably not necessary for, periodic paralysis. Hypokalaemic periodic paralysis is associated with an increase in sodium-potassium-pump-independent potassium influx.
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Affiliation(s)
- V M Oh
- Division of Clinical Pharmacology and Therapeutics, National University Hospital, Singapore
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46
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Schouten-van Meeteren AY, Brouwer OF, Felius A. [Attacks of muscle weakness; a diagnostic problem?]. Ned Tijdschr Geneeskd 1989; 133:2453-5. [PMID: 2594114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
A girl with periodic weakness since the age of two, is presented. Not until four years after the first symptoms appeared hypokalaemic periodic paralysis was diagnosed. Some aspects of this disease are discussed.
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47
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Zabelle JE. [Thyrotoxic hypokalemic periodic paralysis]. Harefuah 1989; 117:368-9. [PMID: 2620878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
A 50-year-old man with thyrotoxicosis complained of recurrent bouts of weakness. On admission all his voluntary muscles were paralyzed except for those of the face, and hypokalemia was found. Thyrotoxic, hypokalemic periodic paralysis is very rare among Caucasians. This is the first case to be reported from Israel.
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48
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Abstract
The cause of weakness was investigated in a patient with adynamia episodica hereditaria without myotonia. A pattern of exercise and rest produced episodes of hyperkalemic periodic paralysis. In addition, local muscle weakness was induced by forearm cooling. Investigations on isolated intercostal muscle demonstrated that a high potassium concentration in the bathing solution triggered a noninactivating membrane current causing depolarization of the muscle fibers. This current was carried by sodium as it could be inhibited by tetrodotoxin. The abnormal sodium conductance led to an increase of sodium within the fibers. This was demonstrated directly by intracellular recordings. Weakness induced by rest after exercise and cold-induced weakness appeared to have different pathomechanisms. In the cold, the muscle fibers retained a normal resting potential, but their excitability was reduced and their mechanical threshold was increased. These findings also provide evidence that the mechanism of cold-induced weakness in adynamia episodica is distinctly different from the cold-induced weakness that occurs in paramyotonia congenita.
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Affiliation(s)
- K Ricker
- Neurologische Universitätsklinik Würzburg, Federal Republic of Germany
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49
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Kelley DE, Gharib H, Kennedy FP, Duda RJ, McManis PG. Thyrotoxic periodic paralysis. Report of 10 cases and review of electromyographic findings. Arch Intern Med 1989; 149:2597-600. [PMID: 2818118 DOI: 10.1001/archinte.149.11.2597] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
We reviewed the clinical characteristics of 10 patients with thyrotoxic periodic paralysis. In these patients, a relatively uniform group of young men, the periodic paralysis developed nearly concurrently with the onset of hyperthyroidism. The attacks were precipitated most frequently by rest and by exercise and, occasionally, by ingestion of a large carbohydrate load. In each patient, the paralysis resolved on return of euthyroidism. The approximate incidence rate for thyrotoxic periodic paralysis in our largely white North American patient population (all hyperthyroidism cases) ranged from 0.1% to 0.2%, which is one tenth the rate reported for Oriental populations. In 7 patients, electrodiagnostic testing revealed characteristic changes in compound muscle action potential amplitude in response to exercise of the muscle being tested.
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Affiliation(s)
- D E Kelley
- Division of Endocrinology, Metabolism, and Internal Medicine, Mayo Clinic, Rochester, MN 55905
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50
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