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.     

High serum creatine kinase levels associated with cylindrical spirals at muscle biopsy

We studied the muscle biopsy from an asymptomatic patient with high serum creatine kinase values. Subsarcolemmal and intermyofibrillar granular inclusions were seen at the light microscopy level. Ultrastructural observation showed clusters of cylindrical spirals (CS). CS are a nonspecific, morphological finding, so far reported only in a few cases, presenting with a wide variety of clinical phenotypes. The case we describe is peculiar because of the complete lack of clinical symptoms. The nature of the CS is unknown; we studied a possible alteration of cytoskeletal proteins using a set of different antibodies against these structures, but none of them reacted with CS. Also, since CS have been described in association with mitochondrial abnormalities, and since in our case CS were strongly positive when stained for succinate dehydrogenase, we performed specific immunohistochemical and genetic studies which ruled out any major mitochondrial alterations.     

Retrospective study of a large population of patients with asymptomatic or minimally symptomatic raised serum creatine kinase levels

A retrospective evaluation of asymptomatic subjects with persistent elevation of serum creatine kinase (CK) levels (hyperCKemia) was made in order to verify the presence of subclinical myopathy or idiopathic hyperCKemia and to define the most appropriate diagnostic pathway. Persistently increased serum CK levels are occasionally encountered in healthy individuals. In 1980 Rowland coined for them the term idiopathic hyperCKemia. Despite the increase of scientific knowledge, several healthy subjects with hyperCKemia still represent a problem for the clinician. We made a retrospective evaluation of 114 asymptomatic or minimally symptomatic individuals with incidentally detected persistent hyperCKemia. They underwent neurological examination and laboratory/instrumental evaluation. Skeletal muscle biopsy was performed and thoroughly investigated. Biochemical and genetic investigations were added in selected cases. Logistic regression analysis was applied. We diagnosed a neuromuscular disorder in 21 patients (18.4 %), and found, by muscle biopsy and/or EMG, pathological but not conclusive findings in 57 subjects (50 %). The statistic correlation between elevated serum CK levels and the probability of making a diagnosis changed according to the age of the patient. Conclusions Muscle biopsy is the basic tool for screening asymptomatic subjects with hyperCkemia. It allowed us to make a diagnosis of disease in 18.4 % of patients, and to detect skeletal muscle abnormalities in 38.6 % of the subjects. Interestingly, 31.6 % of individuals had completely normal muscle findings. These best fit the “diagnosis” of idiopathic hyperCKemia. Received: 13 March 2001, Received in revised form: 3 July 2001, Accepted: 5 July 2001     

Familial scapuloperoneal-type myopathy associated with a marked elevation of serum creatine kinase and hepatomegaly

The proband, a 17-year-old boy, was admitted to our department because of the difficulty in standing on heel. Physical examination revealed a marked weakness and atrophy of bilateral lower legs, especially anterior tibial muscles. Patellar and Achilles tendon reflexes were abolished. Marked hepatomegaly and moderate splenomegaly were noted on abdominal echogram and CT scanning. Serum creatine kinase, lactate dehydrogenase, GOT and GPT were markedly increased. There were no abnormal findings in thyroid function, serum lipid analysis and serum lactate level after ischemic forearm exercise test. EMG of anterior tibial and calf muscles showed a mixture of myogenic and neurogenic patterns and biopsy specimen of calf muscle was compatible with a dystrophic change. Liver biopsy specimen revealed no noticeable change except a slight ballooning of hepatocytes in light microscopy. However, electron microscopic examination showed a marked increase of intracellular vesicles and enlarged smooth ER in which low-density, cotton-like materials were contained. In family study, both his father and paternal uncle were also affected with advanced scapuloperoneal-type myopathy associated with a marked elevation of serum creatine kinase and hepatomegaly. The disorder differs from Miyoshi's distal muscular dystrophy, which shows an early involvement of flexor muscles in lower extremities and is inherited as an autosomal-recessive trait. Although the etiology of hepatomegaly in this case remains to be elucidated, the special findings on electron microscopic study imply the possibility of some unknown metabolic disorder involving both muscle and liver. This disease seems to be a new type of scapuloperoneal-type myopathy, probably having an autosomal-dominant inheritance.     

Familial myopathy with elevated serum angiotensin-converting enzyme,creatine kinase and lactate dehydrogenase isoenzyme 5

Summary A family is reported in which two members presented with proximal myopathy associated with high serum levels of angiotensin-converting enzyme (SACE), creatine kinase (CK), and lactate dehydrogenase isoenzyme 5. Examination of three relatives revealed elevated SACE levels in all of them, but no myopathy. No evidence of sarcoidosis, the most common disease associated with high SACE levels, could be found. Muscle biopsies of the two affected men revealed myopathic features without granuloma formation. Extensive biochemical, metabolic, immunological, and microbiological studies were all non-contributory. Corticosteroid and, in one patient, azathioprine treatment resulted in an improvement of muscle weakness and in a decrease of SACE as well as CK levels.     

Infection-associated decrease of serum creatine kinase levels in Fukuyama congenital muscular dystrophy

BackgroundMarked decreases in serum creatine kinase levels have been noted in Duchenne and Becker muscular dystrophies as rare complications of autoimmune or autoinflammatory diseases.Subjects and methodsThe influence of systemic inflammation on serum creatine kinase levels was reviewed from the charts of three subjects with Fukuyama congenital muscular dystrophy.ResultsA total of 30 infectious events were identified. Elevated serum C-reactive protein levels coincided with decreased creatine kinase levels on 19 occasions. In one subject, administration of 2 mg/kg/d prednisolone for bronchial asthma resulted in a decrease in creatine kinase level on six other occasions.ConclusionApart from an increase in endogenous cortisol secretion, certain inflammation-related molecules could play a role in mitigating muscle cell damage in Fukuyama congenital muscular dystrophy during febrile infectious episodes. Corticosteroids may be a promising agent for the treatment of muscular symptoms in this disorder.     

Myasthenia gravis with inflammatory myopathy without elevation of creatine kinase

Cases of myasthenia gravis with inflammatory myopathy usually show elevated creatine kinase (CK) levels. There are few case reports of myasthenia gravis with inflammatory myopathy without elevated CK levels, and clinical features and useful diagnostic methods for these patients are little known. We describe the case of a 79-year-old man with myasthenia gravis that was complicated with inflammatory myopathy without elevated CK levels and successfully treated with immunological treatment. Initially, he was diagnosed with ocular myasthenia gravis and treated with pyridostigmine, but dysphagia and weakness in the neck and bilateral upper limb without fatigability gradually developed. Needle electromyography revealed myopathic changes, and the results of muscle biopsy were consistent with inflammatory myopathy. Blood tests showed normal CK levels throughout the clinical course and elevated myoglobin levels alone. The possibility of developing inflammatory myopathy in patients with myasthenia gravis cannot be excluded, even if CK levels are normal.     

Autosomal dominant distal myopathy not linked to the known distal myopathy loci

The distal myopathies are clinically, pathologically and genetically heterogenous. Thus far, seven types of distal myopathy have been linked to four chromosome loci. We recently examined four affected members from three generations of an autosomal dominant distal myopathy kindred. A muscle biopsy was performed on the index case. Muscle histopathology showed non-specific myopathic findings including increased variation in fiber size and increased internalized nuclei. No abnormal inclusions or vacuoles were present. Microsatellite markers for the four distal myopathy loci on chromosomes 2, 9 and 14 were studied on affected and several unaffected family members. Affected patients developed distal weakness in anterior foreleg muscles followed by progressive distal upper and proximal lower extremity involvement. Chromosome 2, 9 and 14 regional markers were informative and demonstrated recombinations with affected individuals in the pedigree. The resulting LOD scores obtained from the multipoint analyses gave no evidence of positive linkage to any of the regions and positively excluded (LOD score less than -2) all, or virtually all, of the candidate regions examined. This autosomal dominant distal myopathy family does not show evidence of linkage to any of the known distal myopathy loci, suggesting the existence of at least one more distal myopathy locus. Furthermore, the clinical and pathological features appear distinct from other previously described but genetically-undetermined autosomal dominant distal myopathies.     

Increased serum creatine kinase after exercise: a sex-linked phenomenon

The effect of 2 hours of exercise on the serum creatine kinase (CK) level was investigated in 11 men and 9 women. The mean increase of CK 24 hours after exercise was significantly greater in men. The relative lack of CK elevation in women may: (1) indicate that female muscle is less susceptible to damage by adverse factors; and (2) explain discrepancies in previous reports.     

精神运动性兴奋对血清肌酸激酶活性的影响

肌酸激酶（CK）主要存在于骨骼肌（MM型）、心肌（MB型）,少量（BB型）存在于脑、胎盘、甲状腺。有研究显示精神分裂症患者处于精神运动性兴奋时,血清CK显著升高。本研究探讨精神运动性兴奋和血清CK问关系。     

Increased serum creatine kinase due to hypocalcemia in vitamin D deficiency

An 8-year-old boy with vitamin D-deficiency rickets, increased serum creatine kinase (CK), and hypocalcemia is described. At 5 years of age, he was evaluated because of recurrent tonic seizures. He had growth retardation, microcephaly, quadriplegia, mental retardation, and epilepsy. Muscle strength was difficult to assess because of multiple joint contractures. Deep tendon reflexes were hyperactive. Laboratory data indicated rachitic changes on x-ray, hypocalcemia, low serum 25-hydroxyvitamin D3 (25-OH-D) and 1-alpha-25-dihydroxyvitamin D3 (1-alpha-25-[OH]2-D) levels, a normal response to the Ellsworth-Howard test, and markedly increased CK. Electromyography and nerve conduction velocities were normal. The patient responded to 1-alpha-OH-D treatment with increased serum calcium and normal CK activity; a significant correlation (p less than 0.01) was observed between calcium and log CK. The clinical course and laboratory findings supported the hypothesis that the increased CK was due to hypocalcemia, which in turn was due to the vitamin D deficiency in the severely handicapped child with malnutrition.     

Serum creatine kinase B subunit levels in neurogenic atrophies

Summary This study is an attempt to determine the creatine kinase B (CK-B) subunit levels in neurogenic atrophies. A group of 69 patients was studied and the results were compared with those in a group of 32 patients with muscle disease. The results showed that the CK-B levels are considerably higher in patients with amyotrophic lateral sclerosis (P<0.001) and peroneal muscular atrophy (P<0.001). Further studies in the various subgroups of neurogenic atrophies showed that, regardless of the nosological entity, the CK-B activity is considerably higher: (1) in the widespread as opposed to limited forms (P<0.001); (2) in the chronic than in the acute neurogenic atrophies (P<0.001); and (3) in the active as opposed to residual forms (P<0.02). It is suggested that the increase of CK-B in neurogenic atrophies is a strong indication of an active regeneration process in the denervated muscle.     

血清肌酸激酶与肌萎缩侧索硬化的相关性

目的 探讨血清肌酸激酶(CK)与肌萎缩侧索硬化(ALS)疾病进展率的相关性.方法 分析144例ALS患者和100例健康体检者的临床信息,分析不同亚组ALS患者血清CK差异及与疾病进展率(△FS表示)的相关性.结果 ALS患者血清CK水平男性与女性分别为224.6± 19.3U·L-1、137.8±15.1 U·L-1,对照组分别为63.5±5.3U·L-1、60.2±4.8U·L-1,P值分别＜0.001和0.023,表明无论男性还是女性ALS患者血清CK水平均较对照组升高,差异有统计学意义.另外从年龄来看,无论是＜60岁(209.1±19.6 U·L-1)还是＞60岁(161.3±18.3U·L-1)的ALS患者血清CK水平均较对照组明显升高(P值分别为0.001和0.005).然而ALS患者血清CK水平与ALSFRS-R评分及△FS不存在相关性.对发病部位进行调整后,仅肢体起病ALS患者血清CK与△FS存在弱相关(R2=0.18,P=0.006).结论 ALS患者血清CK水平升高,与疾病进展率不存在相关性.