Myopathy in acute hypothyroidism

Survey analysis of exercise participation and skeletal muscle symptoms in women with hypothyroidism

This study examined the effect of exercise on skeletal muscle symptoms experienced by women with hypothyroidism. An online survey on exercise participation was completed by female participants undergoing treatment for hypothyroidism (n = 580). Basal muscle symptoms (MS) and exercise muscle symptoms were analyzed by the type of exercise performed, cardiovascular/aerobic (CV), resistance training (RT), or both (CVRT). Exercise participation affected MS (F = 7.186, p < .01) with respondents performing a combination of CVRT reporting the lowest basal MS compared to those performing CV (p = .044), RT (p = .031) alone, or those performing no exercise at all (p < .001). Associations between muscle pain (χ² = 7.963, p = .019) and muscle fatigue (χ² = 14.240, p < .001) during exercise and by exercise type were found. Muscle pain during exercise was also associated with an exercise type and frequency (χ² = 24.164, p < .019). Finally, there was an association between recovery from exercise and frequency of exercise bouts (χ² = 32.185, p < .001). Women with hypothyroidism commonly experience skeletal muscle symptoms at rest and during exercise. The results from this study indicate the type of exercise performed may have an impact on the occurrence of these symptoms.

Hypothyroid myopathy: A peculiar clinical presentation of thyroid failure. Review of the literature

Abnormalities in thyroid function are common endocrine disorders that affect 5-10 % of the general population, with hypothyroidism occurring more frequently than hyperthyroidism. Clinical symptoms and signs are often nonspecific, particularly in hypothyroidism. Muscular symptoms (stiffness, myalgias, cramps, easy fatigability) are mentioned by the majority of patients with frank hypothyroidism. Often underestimated is the fact that muscle symptoms may represent the predominant or the only clinical manifestation of hypothyroidism, raising the issue of a differential diagnosis with other causes of myopathy, which sometimes can be difficult. Elevated serum creatine kinase, which not necessarily correlates with the severity of the myopathic symptoms, is certainly suggestive of muscle impairment, though it does not explain the cause. Rare muscular manifestations, associated with hypothyroidism, are rhabdomyolysis, acute compartment syndrome, Hoffman's syndrome and Kocher-Debré-Sémélaigne syndrome. Though the pathogenesis of hypothyroid myopathy is not entirely known, proposed mechanisms include altered glycogenolytic and oxidative metabolism, altered expression of contractile proteins, and neuro-mediated damage. Correlation studies of haplotype, muscle gene expression and protein characterization, could help understanding the pathophysiological mechanisms of this myopathic presentation of hypothyroidism.

Statin-induced bilateral foot drop in a case of hypothyroidism

Muscle involvement is a common manifestation of both clinical and subclinical hypothyroidism, with serum creatine kinase (CK) elevation being probably the most common manifestation, and is seen in up to 90% of patients, but is usually mild (less than 10 times the upper limit of normal). Rhabdomyolysis is a distinctively uncommon presentation of hypothyroidism described usually in the setting of precipitating events such as strenuous exercise, alcohol, or statin use. Rarely rhabdomyolysis and myoedema seen in hypothyroidism can be complicated by the development of anterior compartment syndrome leading to neurovascular compression. We describe a case of a patient with hypothyroidism who developed acute onset bilateral foot drop on initiation of statins. This case highlights the need for cautious use of statins in patients at risk for rhabdomyolysis.

Anti-thyroid drugs-related myopathy: is carbimazole the real culprit?

INTRODUCTION

Anti-thyroid drugs (ATDs)-related myopathy is rarely reported in literature, but once developed, it can cause significant morbidity to patient.

CASE PRESENTATION

A 28-year old Chinese female was treated with carbimazole (CMZ) for Graves' disease with hyperthyroidism. Two weeks later, she developed myalgia and proximal muscle weakness. Investigations showed evidence of myopathy. CMZ was stopped and rapid improvement of clinical condition and biochemical parameters ensued.

CONCLUSIONS

Rapid decrement of thyroid hormone level is recognized as an important association for anti-thyroid drugs (ATDs)-related myopathy; however, the drug effects on muscle tissue cannot be excluded. Further elucidation of pathophysiology and identification of risk factors are needed. After commencing ATDs, early recognition of this rare condition and close monitoring are the essence of management. Different treatment strategies: dose reduction of ATDs, switching to alternative ATDs, with or without addition of thyroid hormone supplement can be applied depending on clinical situation.

Thyroid disease and the nervous system

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

Kocher-Debré-Sémélaigne syndrome diagnosed by autopsy associated with disseminated intravascular coagulation

Kocher-Debré-Sémélaigne syndrome is a rare disease with little literature, which develops with myopathy in infancy associated with neuromuscular alterations, polymyositis with symmetrical proximal muscle weakness, pseudohypertrophy, muscular rigidity and spasms, exercise intolerance, myxoedema, short stature, and cretinism. Male patient aged 18 years old, 1.52 m in height, admitted in the General Hospital of Triângulo Mineiro Federal University on November 11, 2003, complaining of intense diffuse abdominal pain like severe cramps, without triggering factors, associated with asthenia and hyporexia. This seems to be one of the few reports of KDS syndrome diagnoses by autopsy, where alterations in the thyroid gland connected with hypotrophy and probable congenital hypothyroidism were described and resulted in complications such as disseminated intravascular coagulation and hemophagocytic syndrome with fast progression to death of an 18-year-old patient.

Kocher-Debré-Sémélaigne syndrome with pericardial effusion

Kocher-Debré-Sémélaigne syndrome (KDSS) is a rare association of muscular pseudohypertrophy and hypothyroidism in children. We report an 11-year-old female child with hypothyroidism and limb muscle pseudohypertrophy with pericardial effusion. The patient presented with hypertrichosis only. She had dull facies and marked hypertrophy of both calves and cervical muscles. Pericardial effusion was confirmed on investigations. Muscle pseudohypertrophy was a striking feature, and hypothyroidism was confirmed on thyroid studies. Pericardial effusion is known in hypothyroidism but has been very rarely reported with KDSS.

Myopathy Associated with Acute Hypothyroidism following Radioiodine Therapy for Graves Disease in an Adolescent

We describe acute myopathy following I-131 treatment for hyperthyroidism due to Graves Disease (GD) in an adolescent. A 15 year-old diagnosed with GD required treatment with radioactive iodine (I-131) therapy. Six weeks post I-131, he developed generalized muscle cramps. The CK was 19.800 U/L, the total thyroxine was 2.3 mcg/dL (29.6 nmol/L SI) and the estimated free thyroxine (EFT) was 0.5 ng/dL (6.4 pmol/L SI). The ALT was 112 U/L and AST was 364 U/L (normal <35 U/L). The muscle cramps and CK elevation normalized five months after initiation of thyroid replacement therapy. This observation shows that acute myopathy can rarely occur in pediatric patients with GD following treatment with I-131.

Coexistence of thyroid autoimmunity with other autoimmune diseases: friend or foe? Additional aspects on the mosaic of autoimmunity

Autoimmunity encompasses a wide spectrum of diseases from organ-specific diseases like Hashimoto thyroiditis, to systemic diseases such as systemic lupus erythematosus. These diseases are characterized by inflammation and the production of a wide range of autoantibodies directed against multiple autoantigens. Although their etiology is still poorly understood, genetic, immunological, hormonal, and environmental factors are major predisposing and triggering factors. These multiple factors, like pieces in a mosaic, may interplay in different forms, leading to the expression of various autoimmune manifestations and diseases. This phenomenon, which has been referred by us as the "mosaic of autoimmunity", illuminates the diversity of autoimmune manifestations among susceptible individuals. From this theoretical framework we conducted a wide search of the literature, on the prevalence of thyroid autoimmunity, the commonest of the autoimmune conditions, among other autoimmune diseases, and discuss the possible clinical significance of this association.

Hypothyroid myopathy with a strikingly elevated serum creatine kinase level

Although serum creatine kinase (CK) levels are frequently modestly elevated in patients with hypothyroid myopathy, elevations in serum CK to the levels usually seen in inflammatory myopathies or dystrophies are rare. We report a patient with progressive proximal weakness and a serum CK level of over 29,000 IU/L, in whom subsequent laboratory evaluation identified profound hypothyroidism. Thyroid hormone replacement therapy resulted in resolution of clinical symptoms and a marked reduction in the serum CK level. Such a high serum CK level in a patient with hypothyroidism underscores the importance of assessing thyroid function in patients with weakness, regardless of serum CK levels, even when systemic symptoms and signs of hypothyroidism are minimal or absent.

Polymyositis-like syndrome in hypothyroidism: review of cases reported over the past twenty-five years

Polymyositis-like syndrome, with proximal muscle weakness and elevation of muscle enzymes, may be a clinical manifestation of hypothyroidism. To define the clinical, biochemical, electromyographic, and pathologic characteristics of patients with this syndrome, we identified and reviewed by MEDLINE all cases reported in the English literature from January 1, 1975 through December 31, 2000. Thirty-two cases were considered. Fifty-nine percent of the patients were male with a mean age of 54.7 +/- 22.6 years, (+/- 1 standard deviation [SD]). Weakness was described in 100% of patients. Other common clinical manifestations were: delayed tendon reflexes with slow relaxation phase (41%), muscle tenderness (25%), and muscle induration (9%). The mean creatine kinase (CK) was 2164 +/- 1954 U/L (+/- 1 SD) and the mean thyroid-stimulating hormone (TSH) was 114.8 +/- 85.6 mIU/L (+/- 1 SD). Fifty percent of patients had electromyography; half of the studies were normal while the other half showed nonspecific myopathic changes. Biopsies were performed in 80% of the patients. The most common findings were type II fiber atrophy, type I fiber hypertrophy, central nuclei disposition, necrosis, increased percentage of type I fibers, and decreased percentage of type II fibers, inflammatory infiltrate and the presence of core-like structures. The characteristics of polymyositis-like syndrome in hypothyroidism did not differ from those of nonspecific hypothyroid myopathy. Clinical judgment alone may not be sufficient to suspect and detect these patients. Serum TSH levels should be routinely determined in all patients with muscle weakness or elevation of creatine kinase.

Stapedial reflex: a biological index found to be abnormal in clinical and subclinical hypothyroidism

There is only limited evidence for biological parameter abnormalities in subclinical hypothyroidism. The aim of this study was to investigate the impact of varying degrees of thyroid failure on the stapedial reflex as a biological index, and establish its role in the evaluation of the hypothyroid patient. We studied 10 patients with subclinical hypothyroidism, 10 patients with clinical hypothyroidism, and 20 controls. All three parameters of stapedial reflex (amplitude, decay, and threshold) were measured before and after restoration of euthyroidism through thyroxine administration. Data are given as mean +/- SEM. Stapedial reflex maximal amplitudes were different among the groups studied (p < 0.0001), as values in subclinical (4.3 +/- 0.4 mm) and clinical (3.7 +/- 0.3 mm) groups before treatment were lower (p < 0.05) than those of control (5.7 +/- 0.3 mm), and subclinical (6.4 +/- 0.5 mm) and clinical (5.6 +/- 0.4 mm) groups after treatment. Similarly, stapedial reflex decays were different among the groups studied (p < 0.001), as values in subclinical (81 +/- 7 ms) and clinical (89 +/- 4 ms) groups before treatment were higher (p < 0.05) than those in control (65 +/- 2 ms), subclinical (56 +/- 8 ms), and clinical (61 +/- 8 mm) groups after treatment. There was no significant difference among the groups for stapedial reflex threshold or significant correlation between stapedial reflex parameters and thyroid function tests. Stapedial reflex, a biological parameter that reflects neuromuscular status, is abnormal in patients with subclinical and clinical hypothyroidism and returns to normal when clinical and biochemical euthyroidism has been achieved through thyroxine administration.

[Hypothyroid hypertrophic myopathy in adults related to chronic lymphocytic thyroiditis. A case]

The authors report a case of hypothyroid hypertrophic myopathy which reveal chronic lymphocytic thyroiditis. This entity est uncommon, can be the most important sign of hypothyroidism and cure after the institution of thyroid hormone replacement therapy. The E. M. G. is usually myopathic and serum muscle markers (myoglobin and enzymes) increased. Pathologic studies of muscle show caracteritic but non specific and inconstant abnormalities. Hypothyroid myopathy could be caused by a mitochondrial oxidative phosphorylation deficiency or changes in muscle contractile properties (both in fibre type proportion and in the properties of the muscle contractile proteins).

Effects of hypothyroidism on bronchial reactivity in non-asthmatic subjects

The effect of hypothyroidism on non-specific bronchial reactivity was studied in 11 patients without pulmonary disease (mean age 40 (SD 13) years) who had had a total thyroidectomy and radioiodine treatment for thyroid cancer 41 (36) months before the study. All patients when mildly hyperthyroid while having long term thyroxine replacement treatment and once when hypothyroid two weeks after stopping triiodothyronine for the purpose of screening for metastases. Bronchial reactivity was assessed by measuring specific airways conductance (sGaw) after increasing doses of inhaled carbachol (45-1260 micrograms). The dose producing a 35% decrease in sGaw (PD35) was determined from the cumulative log dose-response curve by linear regression analysis. Mean baseline sGaw values were similar when the patients were hypothyroid and when they were hyperthyroid (1.35 (0.36) and 1.41 (0.56) s-1 kPa-1). The interstudy coefficients of variation of baseline sGaw were higher in the thyroid patients than in a euthyroid control group (14% versus 8%). Geometric mean PD35 was lower when the patients were hypothyroid (97 micrograms) than when they were mildly hyperthyroid (192 micrograms). It is concluded that acute hypothyroidism increases non-specific bronchial reactivity in nonasthmatic subjects.

Autoimmune thyroiditis and myopathy. Reversibility of myopathic alterations under thyroxine therapy

A female patient with Hashimoto's autoimmune thyroiditis and myopathic symptoms is reported. Besides a myopathic pattern, widespread spontaneous pathological activity was found in the affected musculature. Under thyroxin therapy, both the clinical picture and the electromyographic findings normalized completely within a few weeks.