Hoffman's syndrome: pseudohypertrophic myopathy as initial manifestation of hypothyroidism. Case report

Hoffmann's syndrome in the differential work-up of myopathic complaints: a case report

BACKGROUND

Hoffmann's syndrome is a rare form of hypothyroid myopathy in adults, which is mainly characterized by muscular weakness and muscular pseudohypertrophy.

CASE PRESENTATION

We report about a 61-year-old Western European man with myalgia, myxedema and pseudohypertrophy of the calf muscles. Laboratory tests revealed significantly elevated thyroid stimulating hormone (TSH) and creatine kinase (CK). Muscle MRI showed muscular hypertrophy of the lower limbs, but no signs of myositis or myopathy (no gadolinium enhancement, no edema, no fatty degeneration). In addition, electromyography (EMG) detected spontaneous activity. After the beginning of thyroxin-therapy it took six months until the muscle weakness improved and the myalgia regressed.

CONCLUSIONS

Here, we focus on diagnostic routines and typical findings to differentiate Hoffmann's syndrome from other myopathies. Clinical hallmarks of Hoffmann's syndrome are pseudohypertrophy and weakness of the calf muscles in combination with elevated CK and elevated TSH. EMG is well suited to detect the involvement of the muscles and muscle MRI helps to differentiate it from other myopathies. Hoffmann's syndrome is a rare myopathy due to hypothyroidism and plays a role in the differential diagnosis of myopathic complaints even if hypothyroidism has not been detected before.

Hoffman syndrome with the classic sign of myoedema and an unusual finding of systolic heart failure

A man in his 20s presented with a 6-year history of calf muscle hypertrophy, proximal muscle weakness and muscle cramps. Along with this, he also had patchy hair loss, facial puffiness and slurring of speech. On examination, he had mild symmetrical proximal muscle weakness, a delayed relaxation phase of his deep tendon reflexes and a rare neurological sign of myoedema. His laboratory investigations revealed elevated thyroid-stimulating hormone levels with high creatine kinase levels, and an echocardiogram showed left ventricular systolic dysfunction. He was diagnosed with Hoffman syndrome, a rare pseudohypertrophic myopathy associated with severe and prolonged hypothyroidism. He had an excellent response to thyroid hormone replacement.

Hoffmann's Syndrome Secondary to Pendred Syndrome: A Rare Case

Hoffmann's syndrome (HS) is a rare manifestation of hypothyroidism myopathy that presents with weakness, stiffness, and eventually pseudohypertrophy of muscles, especially calf muscles. We report a case of a 28-year-old male who presented with the history of generalized weakness with swelling in lower limbs and gradual progressive facial puffiness for the past few years. Physical examination of our patient showed diffuse bilateral pseudohypertrophy of deltoid and calf muscles with positive Gowers' sign (GS). Laboratory results of low serum thyroid hormones and muscle biopsy report confirmed the diagnosis of HS. Pendred syndrome (PS) is a genetic disorder leading to congenital bilateral sensorineural hearing loss with mild hypothyroidism. On account of his congenital bilateral sensorineural hearing loss and negative serum anti-thyroid peroxidase antibodies (anti-TPO Ab), PS was declared as the cause of HS in this case. Our patient showed excellent response to levothyroxine therapy with progressive improvement in his symptoms. We outlined this case due to its rarity.

MUSCULAR HYPERTROPHY AS ATYPICAL INITIAL PRESENTATION OF HYPOTHYROIDISM

Hypothyroidism is a common endocrine disease with characteristic symptoms and signs such as fatigue, weight gain, intolerance of cold, constipation, depression, mental slowdown and muscle cramps. Myopathic changes are observed in 30-80% of patients with hypothyroidism, but muscular hypertrophy with muscle stiffness has been reported in less than 10% of patients. Hoffmann's syndrome is a specific form of the hypothyroid-associated myopathy, rarely seen. Symptoms of this syndrome include proximal muscle weakness, hypertrophies in extremities, stiffness, muscle cramps, spontaneous muscle pain; and are associated with increased muscle enzymes. These findings can be seen at any time during hypothyroidism. Hofmann's syndrome has a very good prognosis. Its response to hormone replacement therapy is very good. Therefore, in patients with myopathy-like symptoms, considering in the differential diagnosis that the myopathy may be a reflection of hypothyroidism will facilitate the diagnosis and treatment. In this case, we aimed to present together Hashimoto thyroiditis and muscular hypertrophy, which is an atypical presentation of hypothyroidism and rarely seen in the literature, namely Hoffmann's syndrome.

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.

A Rare Manifestation of Hypothyroid Myopathy: Hoffmann's Syndrome

Hypothyroid myopathy is observed frequently and the resolution of the clinical manifestations of myopathy following thyroid hormone replacement is well known. However, a specific subtype of hypothyroid myopathy, Hoffmann's syndrome, characterized by increased muscular mass (pseudohypertrophy), proximal muscle weakness, muscle stiffness and cramps, is rarely reported. Herein, we describe a 34-year-old male who presented with proximal muscle weakness and non-pitting edema of the lower extremities. He initially visited the neurology department where he was suspected of having polymyositis. Additional laboratory evaluation revealed profound autoimmune hypothyroidism and elevated muscle enzymes including creatine kinase. The patient was started on levothyroxine treatment and, subsequently, clinical symptoms and biochemical parameters resolved with the treatment. The present case highlights that hypothyroidism should be considered in the differential diagnosis of musculoskeletal symptoms even in the absence of overt manifestations of hypothyroidism. To our knowledge, this is the first case reported in Korea.

Rheumatic and autoimmune thyroid disorders: a causal or casual relationship?

A number of dysfunctions may affect the thyroid gland leading either to hyper- or hypothyroidism which are mediated by autoimmune mechanisms. Thyroid abnormalities may represent an isolated alteration or they may be the harbinger of forthcoming disorders as is the case of well-characterized polyendocrine syndromes. Also, they may precede or follow the appearance of rheumatic manifestations in patients affected with connective tissue diseases or rheumatoid arthritis. The mechanisms by which autoimmune thyroid disorders may be linked to systemic autoimmune diseases have not been fully unraveled yet, however alterations of common pathways are suggested by shared genetic variants affecting autoantigen presentation and regulation of the immune response. On the other hand, the higher prevalence of autoimmune thyroid disorders over rheumatic diseases compels the chance of a mere causal concomitancy in the same patient. The aim of our paper is to provide an overview of available data on thyroid involvement in different rheumatic diseases and to go over the main rheumatic manifestations in the context of autoimmune thyroid diseases.

Hoffmann's syndrome with unusually long duration: Report on clinical, laboratory and muscle imaging findings in two cases

Two adult men presented with the rare Hoffmann's syndrome (HS). Case 1: A 35-year-old male patient had progressive stiffness of lower limbs of 13 years and generalized muscle hypertrophy and myalgia of 3 years duration. Had periorbital edema, dry skin, generalized muscle hypertrophy and spastic dysarthria with hoarseness. Muscle power was normal. Jaw jerk and deep tendon reflexes were exaggerated. Case 2: A 24-year-old male patient presented with muscle hypertrophy from childhood, slowness in motor activities and hearing impairment. For 6 months, he had severe muscle pains, cramps and further increase in hypertrophy. He had yellow tinged, dry skin, hoarseness of voice, gross muscle hypertrophy and minimal weakness. Both had markedly elevated serum creatine kinase (CK) levels and high thyroid stimulating hormone, low free triiodothyronine and free thyroxine levels. Levothyroxine treatment demonstrated remarkable reduction in muscle bulk at 2 months in both and no symptoms at 6 months. Magnetic resonance imaging of lower limbs in both cases revealed almost identical features with involvement of the muscles of posterior and adductor compartment of thighs and posterior and lateral compartments of the legs. Differential diagnosis of long duration muscle pseudohypertrophy and elevated CK levels should include HS.

Hoffmann syndrome: a case report

Hoffmann syndrome is a rare form of hypothyroid myopathy in adults characterized by presence of muscle weakness, stiffness and pseudohypertrophy. We report a 39 year old male with primary hypothyroidism diagnosed at childhood and not on regular thyroxine therapy who presented with fatigue, cold intolerance, constipation, exertional breathlessness, progressive proximal muscle weakness and swelling of the legs for one year. Examination revealed pseudohypertrophy of calf muscles with marked symmetrical proximal upper and lower limb weakness. His TSH and Creatine phosphokinase (CPK) levels were significantly elevated and electromyography (EMG) was compatible with myopathic disorder. After institution of thyroxine therapy his weakness improved markedly and pseudohypertrophy regressed in two months. We report this case because of its rarity.

Hypothyroid myopathy with manifestations of Hoffman's syndrome and myasthenia gravis

Although hypothyroid myopathy is seen frequently and the relationship with autoimmune hypothyroidism and myasthenia gravis is well known, specific forms of hypothyroid myopathy such as Hoffman's syndrome (HS) are rarely described. Here we describe a 40-year-old patient with Hashimoto thyroiditis showing symptoms and signs of two discrete forms of hypothyroid myopathy (HS and myasthenic syndrome) together. To our knowledge this is the first reported case with features of both of these syndromes. We discuss the diagnosis, speculate whether this patient may represent a unique form of hypothyroid myopathy, and report the 6-month follow-up of the patient both clinically and electrophysiologically.

Myotonie et hypothyroïdie

INTRODUCTION

Hypothyroidism is frequently associated with different neuromuscular disorders. However myotonia is rarely a revealing feature.

CLINICAL CASES

Two patients aged 28 and 31 years consulted for a progressive myotonia. Blood and thyroid analysis revealed peripheral hypothyroidism with low FT4 and high TSH levels. Outcome was favorable with thyroid hormone substitution. Myotonia regressed and thyroid hormone levels returned to normal.

CONCLUSION

Myotonia may reveal hypothyroidism. The pathogenic mechanism of this myotonia is an unknown. Good outcome with thyroid hormone substitution requires a systematic thyroid hormone screening in patients presenting neuromuscular manifestations.

[A case of myopathy associated with hypothyroidism and hyperprolactinaemia]

We report a case of a serious myopathy related to hypothyroidism with pituitary enlargement and hyperprolactinemia.

CASE REPORT

Mr D.L 33 years old man suffering from myalgia, muscular weakness and cramps for six months. The laboratory check-up revealed a high serum creatin phosphokinase level, an autoimmune hypothyroidism, hyperprolactinemia and pituitary enlargement. The electromyogram was normal and the muscle biopsy showed no obvious inflammation. The outcome was favourable under L. thyroxin.

DISCUSSION

The frequency of myopathy during hypothyroidism ranges from 30 to 80%. The main symptoms related are weakness, muscular cramps and myalgia. However, hyperprolactinemia and pituitary enlargement described in this case are due to reactional mechanism. These several hypothyroid manifestations improve remarkably under L.thyroxin.

CONCLUSION

Proximal myopathy may rarely be displayed as the sole manifestation of hypothyroidism. Therefore, it is recommended that hypothyroid myopathy should be taken into account during differential diagnosis of proximal muscle weakness.